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2006 Spec Moto 125 Standards (Stock moto)
1.0 Induction System
Air Filters and Air Boxes
Motor must be equipped with either Air Filter or Air box. Air Box Requirements may be imposed by Local Track requirements. In cases where an Air box is required they may have some form of filtration and must be commercially available for under $60
USD from the Track Operator or a supplier designated by the Track Operator.Fuel Pump
Fuel Pump(s) must be driven by pulse pressure in the motor, no Electronic Fuel Pumps. Dual Fuel Pumps for Pump around Carburetors allowed. Fuel Pump must be a separate component from the Carburetor.Carburetor
Pumper Carburetors not allowed.
Pump around Carburetors are allowed.
Any make/model of Float Bowl style carburetor allowed
Venturi Diameter not allowed to exceed 38.6 mm in diameter.
Using Inside calipers measure widest point downstream from slide.Carburetor Boot
The stock 1999 CR125 30? Boot is recommended. As this part is is optimal from the factory and measurements very subjective, there are no other restrictions on it.
For Seat Clearance Purposes, the RS125 Straight Boot or the RS125 5? boot are allowed. As a handicap the Stuffer Lobes of the Straight Boot and the 5? boot must be cut off flush with mounting surface and may not extend into Reed cage.Reed cage and Reeds
Reeds are open.
Reed cage must be 1999 CR125 6-Petal Design. No material may be added or removed.
Reed Stops must be 1999 CR125. Bending stops to fit into unaltered reed throat of crankcase allowed. No removal of material from Reed Stops allowed.2.0 Exhaust System
Pipe/Expansion chamber Max Circumference: 17-1/8 (440mm)
Pipe is restricted to the following RLV 6800 series, RCE T3, and RLV-R4 The maximum size of circumference of any portion of the pipe is 17-1/8″. (440 mm) Addition of exhaust gas temperature lead is legal, but hole must be plugged if exhaust temp lead is not used. External mounting brackets may be added.
Measure largest diameter of the drum section (between convergence and divergence cones) with a flexible tape measure. Pipes may have obstructions such as mounting flanges, metal tags, seams, or weldments in the way. It is the racers obligation to assure there is an area where the circumference can be measured by tech.Silencer
Silencer should be a minimum of 10″ long by 2-1/2″ in diameter. Tracks that have noise emission requirements shall provide any necessary supplemental rules for where noise abatement is required.Exhaust Flange
OpenCylinder Head Model
3.0 Cylinder Head
1998-1999 CR125 Cylinder Head only. This cylinder head has 5 holes for mounting studs in a concentric circle.
Cooling spigots may be replaced with a substitute in the original location. One spigot may be plugged for single water outlet.Combustion Chamber Profile
Using approved Shockwave 99 CR125 Cylinder Head Gage, inspect Parabola of Chamber Dome and Squish recess for apparent gaps greater the .005″ deep. Competitor may clean off carbon build up with abrasive pad. Spark Plug sealing surface must be above spark plug stem of gage. The overall height is measured also.
“The “go” portion of the stem of the profile gage should protrude above the spark plug sealing surface. The “No Go” portion of the stem should not.”Piston – Cylinder Deck Minimum is .020″ (.50mm)
Rotate flywheel to bring piston close (to but not at) Top Dead Center. Set Depth Gage on Cylinder Deck with edge facing down over piston. Rotate piston to TDC and past. Piston impact with gage should not felt by inspector. – Alternate method (not preferred) – measure depth at TDC with Depth Gage.Cylinder Head Gasket thickness range – .008″-.012″ (.20 – .30 mm)
Aftermarket Head Gaskets may be used.
Measure thickness of Head Gasket with calipers4.0 Cylinder-Bore-Stroke-Piston
Cylinder must be unaltered 1999 CR125.Exhaust Port – Cylinder top Minimum Distance: 1.145″ (29.08 mm)
Note 1: This measurement is taken from the top of the cylinder to the exhaust port opening. It is not intended to measure opening in relation to piston travel alone. Note 2: Exhaust Valves may be plugged. Plug is a non-tech item. Plugs may have blades removed or angled to blend flow into passage. In some cases the blades may appear to provide a false reading of depth – this is OK as long as inspection does not indicate any grinding. CR125 Exhaust ports have a height that is controlled by the machining operation of the Exhaust valve and is very accurate in controlling port location.
Insert Approved Port Height Check Gage (1.140″ Step) tool into Cylinder in line with Exhaust Port Center. Inspect through Port – Gage end should not extend past Port Opening at edge. Check both ports at highest points.Stroke:2.149″ (54.59 mm) maximum
Piston may rock on pin. Measure depths directly above pin. Measure Piston depth at TDC. Measure Piston depth at BDC. Subtract TDC from BDC to get the stroke.Bore: 2.129″ (54.10 mm) Maximum
Measure with Inside Micrometer.Cylinder Height Minimum: 3.305″ (83.95mm)
Remove Cylinder and measure Base Surface to Head Surface with calipers.Base Gasket Thickness: .010 – .030
Measure Base GasketsPort Inspection
If Ports appear substantially different the Tech Inspector should follow up with a close inspection for any evidence of grinding to modify the port sizes. Small differences in sizes make very little difference in performance gains. Any DQ actions should be based on obvious modification evidence.Ancillaries
Studs Bolts and washers are non-tech.Piston
Flat Top design only.
Distance from Piston Pin edge to top of Piston – .800 – .810″ (20.32 mm – 20.57
mm)
Slide piston pin out of piston with no more than 1/4″ protruding. Measure depth from top of piston to pin top edge with caliper slide.
Piston Ring Minimum Thickness: .038″ (.96 mm)
Measure with calipers.Stock 1999 Honda CR125 Coil
5.0 Ignition
Stock 1999 Honda CR125 Capacitive Discharge Ignition (CDI) System. Denso Part Number 071000-1410 should be legible on Tag. CDI cannot be DQ’d over TAG legibility. This only serves to validate component.
CDI Grid Swap
The Tech Steward shall have the option to collect CDI Units between heats and redistribute them at impound. This is at the Tech Steward/Promoters discretion. It is only recommended when some motors appear by sound to be revving a little higher then others, or needing less gearshifts on a given lap.Stock 1999 Honda CR125 Flywheel and stator.
No material may be removed from Flywheel. Flywheel Key may not be machined to offset timing. Stator may be mechanically advanced or retarded. Stator Plate may be slotted for adjustmentSpark Plug and Ignition Wires are non-tech.
No additional components may be electrically connected to the CDI or Coil. Only an inductive RPM sensor may be used
6.0 Crankcase
Kick Start Boss may be removed and plugged. The 5? horizontal RS Boot does not require the boss to be removed to fit most carburetors.
Internal Crankcase modifications are not allowed. No excessive material removal or addition. Some grinding of flash is be allowed not to exceed .04″ in depth. (Some cases come with flash removed)
Legacy Cases- The use of legacy cases, ie, fully modified cases may be utilized. The use of a legacy motor must utilize the other stock components such as cylinder, head, ignition etc. A weight penalty may be imposed (10 pounds). The use of Legacy motors is good through 2007.Crankshaft must be OEM Honda CR125 any year. May be polished for slip fit of bearings. This does not enhance performance but allows for easier assembly/disassembly. Precision alignment of crank is allowed. No material may be added or removed from Crank Wheels or Rod.
Main Bearing Balls to be steel material.
Seals and gaskets are non-tech. Seals must be same size and diameter as OEM.
7.0 Clutch and Gearbox
Stock OEM Honda CR125 Clutch components only. All 7 Clutch Disks and 6 Clutch Plates must be installed. Stock OEM 1999 CR125 Clutch Basket and Pressure Plate. Any Clutch Springs allowed.Transmission Bearing Balls and Rollers to be steel material.
Micro-polishing of Gears allowed. There are no power gains with this treatment, and seldom any performance gains. Occasionally Micro-polishing may help solve a sticking gear problem that normally corrects itself after a few hours of use.
Five or six gears are allowed.
Gears are per the 1994-96 ratios as follows; First – 14/33
Second – 15/28
Third – 19/29
Fourth – 21/27
Fifth – 23/26
Sixth – 24/24Gary
The set of rules you posted have gone through a couple of revisions to tighten up a couple of loopholes. The final set of those rules will be up and posted on the internet with a day or two. (From right now, 7:24 am, March 8th) It may all change in a hour!!!!!!
What the CSC is going to do I have no insite to offer. I can only assume they will be some version of SKUSA’s last years rules or the new ones developed by Dave Larson and friends. Actually they are very similar except for the limitation to 1999 cylinder/head only and the inclusion of the RS boot. Dave’s group has also made provisions for “legacy” cases as a way of boosting entrants.
If I were building an engine today, I would restrict myself to the 1999 stuff, slot the stator to advance the timing, use the RCE T3 pipe with the big M4 silencer and go have fun. With the exception of the stator and pipe, you will be legal in most parts of the country including those tracks with sound issues. Grand Junction will love the M4. Even without an airbox, a stocker with the M4 is quieter than most ICCs!
Most rules makers have figured out that they have to allow slotting of the stator. The intent of the rule “not” to allow slotting is to control timing. However, its possible to “cheat” the timing by moving the trigger point on the back side of the stator and it’s impossible to detect that the trigger has been moved. The racer/engine builder who know this trick will be able to gain a pony that the racer without such abilities can not get. Better to open up the rules to allow slotting so that everyone can get that pony. Most of the better builders don’t charge for slotting anyway as it makes their job easier.
The reason for not allowing the 2001 stuff has to do with tech. The 1999 cylinder is very easy to tech as the exhaust port height is machined. It doesn’t vary more than .003″. The overall cylinder height doesn’t vary more than .001″. These numbers are well known and very easy to measure. Alterations just jump out. Even a replated cylinder is easy to find for they grow in the plating process and will be out of spec on height!
The 2001 exhaust port height is as cast and can vary .015″ or more. It opens up the class to the “magic” cylinder (one with a very low port height) and there is no way to tech for it or prevent a builder from charging big bucks for it. The magic 1999 cyclinder just doesn’t exist.
There is also a huge problem with ignitions. It is possible to get a PI (programable ignition) potted in an OEM case and without some very, very sosphisticated testing equipment, you can’t tech it. The way to prevent altered igntions is to perform grid swaps with the CDI boxes. However, 1999 and 2001 are not compatable and can not be swaped. They have already had this problem in SO-Cal. Just another reason to limit it to the 1999 only. If the tech people suspect an altered ignition, they can just come through the grid collect all the CDI boxes and redistribute them. Fair and simple.
The final nail in all this is our cylinder head profile tool. With this one tool, we can measure the cylinder head profile and overall cylinder head height. Any alterations from stock just jump out. A guy in Florida found out the hard way. The same gage also checks piston deck height. This will catch anyone who machined the cases or the crank to increase compression.
The Rules that Dave Larson (Tag USA) and company have developed are the best set of rules for spec Honda. They are fair, techable and do the best job of limiting modifications and creating a level playing field. There are no secrets.
Nice, not that it really matters to me, but one thing sounded sort of weird to me.
“If the tech people suspect an altered ignition, they can just come through the grid collect all the CDI boxes and redistribute them. Fair and simple.”
Simple ya, but fair to the guy that ended up with the other guys suspect ignition box to run the main with?
How sosphisticated is it to be able to test stock boxes? :loony:
Let me ask you, would you spend $1500 on a PI in stock case if you knew you could lose it in a grid swap? The guy who gets the cheater box gets to go like stink! (at least for that day)
A couple of years ago Mike Speed made a PI in a stock case and from looking at, you could not tell it from a stock box. Its a real problem. The best solution is to go to a spec igntion that has tech features built in to prevent tampering. I’ve talked wth Mike about that and it can be done easily. But there’s no way we can introduce such a box now.
We are very close to answering this question.
The funny part of the equation is availability. I am a fan of ’99 only, however nobody can get one untill May.
2001, or 2000 is a “tech” issue, not a performance issue.
The real question is
Do we let the customer buy a motor now, and get ready for the season, or do they have to wait until May? (Just to make tech easier)
The reason behind the RS boot is for larger seats and fitting the carb.
I have an XL seat, am 60lbs over the weight limit and the stock boot works just fine.I know that a stock motor with a 2001 head combo will be dyno’d to fully answer the question on hp. soon!! That is what we are really waiting on.
sorry for the delay.
If you built a stock motor following the SKUSA rules from last year, Colo and southern Calf. would be on the same page.
Who knows what the SuperNats would follow, as that is where most of us would go to.
Standing by.
Thanks for your patience.
(if you wanted to buy a motor right now, you would have to wait till May for a top end, so I’m trying to get the “facts” so we all can move ahead.
As Doug stated, Dave Larsen keeps changing his rules by the hour. It is best to let the dust settle before any final desision is made.
Once again, sorry for the delay.Thanks, I allways woundered why the CDI swap.
I have herd that there is more power to be had in a 2001 cylender – is that true?
What are the rules going to be on legacy cases, or are they going to be allowed at all – I think SKUSA had a weight penelty, and that legacy cases were supposed to be gone by 2007.
Thanks for the input!!
Gary
While the 1999 cylinder and head are currently on back order from Honda, there are plenty of them available if a person wants one. There is NO shortage of them today. I made 5 calls on Friday of last week and found plenty of engines available and plenty of cylinders available. If a person wants a 1999, he can have one right now! There is no need to wait till May. One of the many advantages of having a supply chain with thousands of outlets! The argument to allow 2001 because of shortages is a non issue as far as I’m concerned.
Dave is changing his rules because of loopholes we are finding, ie, ways to cheat. The SKUSA rules of last year have more holes than Albert Hall as they are finding out in So-Cal.
Doug,
Will you answer Gary’s question?
Does the 2001 have more HP Stock?
What are the loopholes you speak of?
I have a note from you last week talking about how good Daves rules are, and now they have totally changed.
Could you please list the facts, loopholes and hp advantages of a 2001.
Thanks,
JimThanks EVERYONE!!
This is a discussion I have wanted to see for some time. Personally, I think the more discussion – the more input – the better the rules. Personally, I can put my motor in compliance with any set of rules – and I certianly will take advantage of what is allowed. I think if we had a set of rules hammered out and set in stone it would save a lot of money to the racers (depending), and prematurlay end a lot of race day confusion.
I’ll bite my tung on my opinon of having a nationaly sanctioned set of rules for stock moto (I’m a former stock yami guy), and concentrate on what were doing locally here.
My main concern is that the racers should be aware of what the rules are (what ever they may be) WELL in advance of any race series – give the guys a chance to configure / test / tune.
Special thanks to Doug and Jim (Keep up the good work!!), as well as anybody that gives input to what we really want here – it’s OUR sport…
Respectfully,
Gary
Does the 2001 make more power, the short answer is yes but its not much. More importantly, it develops the power differently and in different parts of the curve. Its mainly the ignition. The curve is such that the top is flatter with more over rev. And you can’t just mandate the 1999 ignition. The 2001 cylinder has the advantage because the 2001 ignition was developed for its port timing. With two quality drivers with equal chassis, the 2001 will be the winner everytime. The more open the track, the more the 2001 has the upper hand.
To make matters worse, you can’t actually buy a 2001 kit engine with a 6 speed box. You have to buy a 1999 and have them swap you parts. Or you buy it from the one and only engine builder in the country who is pushing the 2001 option. It’s really that simple.
The thing is this whole thing is so unneccessary. For a class to grow as this one has the potential, the more spec the better. The fewer options the better. Like Rotax and other spec classes, there is a very strong attraction for them. The tighter the rules and the more developed the tech preocedures, the more likely this class will become the class that will move shifter racing back to the forefront. I have no interest in a class that means you put a 2001 top on for long tracks and a 1999 for short tracks. How stupid is that? How does this help control costs? Isn’t cost control one of the central points of the stock moto class? Why screw that up?
Have we learned nothing in the last 10 years? Five years ago shifter racing was huge. We would get 150 shifters to a single PMT. We had LCQs for most classes! The SuperNats used to draw 350 racers for 5 classes, now it can’t draw that many with 10! There was a license structure that you had to earn your way to the top. It took 3 years for a racer to attain the top level. But it all fell apart when we let the rules get out of control. There were too many options and the costs got absolutely silly. It cost $6,000 for a blessed moto package and they blew up with regularity. Kind of like ICCs now! If you look back over the last 20 years of karting, the classes that have grown and flourished have all been very tightly controlled. That is why Yamaha based single speed karts are still the most popular sprint 2 cycle karts going. And they have changed very little and every dimension is tightly controlled. Spec honda should be the same, very limited options, very tightly controlled.
Actually, if you have been reading Dave’s rules and been involved as I have in their development, you will notice that the basics have not changed at all. There is nothing that is now allowed that wasn’t allowed 6 weeks ago when we started. What has changed is that Dave has added dimensions and tech procedures. What good is a rule if you can’t tech it? Every word has been gone over and over to look for and stop every possbile chance for a builder to screw this class up. The rules are very solid now. At least 10 different builders and tech personal around the country have gone over them to find and plug every possible loophole.
The bottom line is this, outside of PKC, there is NO support for the 2001 cylinder. Not a single series in the entire country that has a stock moto class allows the 2001. The only place to allow the 2001 is PKC. If a guy builds a 1999, he can race everywhere. If he has a 2001, he can only race in So-Cal. And don’t think for one second that racers don’t look for holes. In Florida, they dq’ed a guys at both Homestead and Moroso. After the dq’s, several guys dropped out for they knew they wouldn’t pass.
What maybe hard for some to understand is how much fun it is to race in a class where the motor is not the reason you win or lose. When we were in Florida, the Rotax senior class had over 46 drivers in Homestead. 46 karts with equal motors. Do you have any idea how hard it is to pass when you don’t have a hp advantage? You actually have to drive the kart! Whats more cool is that no matter who builds the engine, not matter how much money you spend, the engine you buy from Rotax has just as much power.
Spec Honda has every bit as much potential. Shifter engines that all have equal power, cost less than $3,500 complete and last all season. The class could become huge. Opening up to more options just rachets up the costs and makes the engines less equal. This goes againest the very reason for having the class in the first place. We did this before and it didn’t work. Why do we have to do it again?
Thanks for the history lesson on fully built moto’s and entries at the SuperNats.
How much more HP difference is there.
Facts based on dyno runs?
“Not much” isn’t the answer.
What are the loopholes?
Thanks,
Jim
ps. I didn’t ask who was selling 2001, I was asking what the loopholes were and how much hp difference there was. How did ICC come into the thread?History lessons are for those who are fairly recent to the sport. There is an old adage, “Those who don’t understand history are doomed to repeat past mistakes.” or something like that. I try to point out the past so that we don’t continue to make the same mistakes over and over again.
Moto died when we let the rules get out of control, costs escalated and racers dropped out or moved to other forms of motorsports. ICC’s have followed the same rocky road. It now costs $6,000 for a blessed motor, they don’t last very long and people are dropping out. Sales of built ICCs have dropped to almost nothing. I talked with one of the major importers of ICC engines in Florida and he told me he had only sold 3 engines so far this year. I’ve sold over 4 dozen CR-125 motor mounts so far this year and I’m not the big seller of mounts in the country. They are all going on stockers. I think that small fact should be of interest to track owners, rules makers and promotors of our sport. It is screaming at you, telling you where the market is heading.
On the dyno, the 2001 has a bit more hp. The overall number varies from dyno to dyno but the difference is around a pony, maybe a bit less. In the grand scheme of things, thats no much. But its far more important as to where the power is and the hp curve. The 2001 has better over rev and a flatter top hp. The 1999 has more bottom end and mid range. The 1999 should be stronger on tracks that require better acceleration where the 2001 should do better on more open tracks where over rev and a flat curve of peak hp will be an advantage. So as the class grows and becomes more competitive, some racers will use a 1999 top and ignition for acceleration tracks and 2001 on open fast tracks.
As we have found in dynoing Tag engines, total hp is not nearly the whole story. The power curve is what’s important. If you look at the original work SKUSA did with Tag, they dynoed every engine and set weights based on dyno runs. As we found, there isn’t a single set of “magic” weights that works well at every track. Every engine develops the power differently, even if they all develop the same TOTAL power. And it gives one an advantage over the other.
Spec Honda is no different. While the over all power is not significantly different, the power curve is signficantly different. One will and does have the advantage over the other in certain circumstances. This very fact will hurt the class. The entire point is why go down this road unless we have a compelling reason to go!
The primary reasons for this class are as follows.
1. Level playing field
2. Lower costs
3. Easy and controllable techAdding the 2001 cylinder does not level the playing field. In fact, it does just the opposite.
It does not lower costs for its more expensive to put a 2001 together. It also opens up the possible need for multiple top end/ignition combinations depending on track conditions. Potentially more expensive.
For a varity of reasons, the 2001 is harder to tech. Certain dimensions, particularly port height, are far more open and variable than on the 1999. Since the ignition is so critical to the power curve, opening up the ignition to multiple years that are not compatable across the years means you lose control of one of the most important aspects of the engines. As I stated earlier, limiting it to just the 1999, we have easy and fair ways to control the CDI boxes.
You want loopholes, here they are. You can’t tech a 2001 for port height alteration. Since they are as cast, they vary. A sharp builder could alter the height and you can’t tech for it. The 1999 is machined and doesn’t vary more than .003″ Alter it, you can be easily nailed.
Just using a cc head volumn is not enough. I can open up the ring gap so that more oil flows out through the ring gap while you are filling the head with oil giving a false reading. Plus, many tech guys don’t even know how to use a burrette.
With out profile tools, you can not detect an altered head. No such tools exist for the 2001 nor is there any interest in developing them.
Ignitions are almost impossible to tech yet they have tremendous inpact on power production. Things like stators, coils and CDI do not interchange across years. The best and easiest way to control ingnitions is to perform grid swaps of CDIs. If you have multiple years and multiple combinations, you take this very powerful tool away from the tech guys. You might as well just open up ignitions. But then for those who don’t know history, we already been down that road and it didn’t work.
I given you the facts on power, explained the reasons for the differences, showed several loopholes and given what I think are factual reasons, based on both past experiences and logic as to why we don’t what to open it up to multiple years.
THANK YOU!
That’s what we are looking for. Not all the jumbled up past, what happened, who is wrong, that didn’t work, this is bettrer, blah, blah, blah.
Since you make a very good point for 1999, why do they allow fully built cases? Who decided that 10 lbs would level that field?
If 10 lbs. does, what are the hp numbers and power curve of a “legacy” motor?
It’s a good thing you are calling it “spec” because it’s far from “stock”.Bad? No, but perception is what we have to fight against, not reality.
Jim
For the record, I love my stock moto. I just need to know why and what to sell the new customer, and be able to tech at the CSC races.
The only downside, the new guy isn’t going to know what he can do to “spec” his motor to compete againt you.
If we only had a tuning guide for “spec” motors so the field really is level…Ok, I don’t think you can better explain the reasons for running a single year jug better than Doug has.
a racers prespective:
I’m no motor genius – but through talking to different people, understand what Doug is saying – basically its the TAG thing all over again. Thus – to be competitive in a series that allows 2 different top ends, to me – means that I need different configurations for different tracks. That meens the extra expense of the parts, twice the testing and cost involved in doing so. This would keep me out of the series – I figure at that point it’s gonna be the guys with the dyno’s and the money that are gonna be up front, so why bother – I’ll just go run a couple club races and weekends for fun.
I think stock moto has a lot of potential to pull people into the sport and would hate to see the motor builders / tuners kill it off. Keep it simple – eliminate as many options as possible now – even the RS boot thing – the less options and the more spicific the rules (in my opinion), the more money I can spend on tires / track time / fun.
Just my opinion,
Gary
Jim it doesn’t take a dyno to figure the end result the racers would have to spend to play in stock moto. Doug is spot on with the forseen problems the stock moto class has.
ICC is into this thread, because $3500.00 can buy you a 2006 kart racing motor that is allowed to be run in many shifter classes rather than just one.
Shure they cost more to maintain at a competitive level. But with out the elimination of loop holes the stocker honda is going to cost more to maintain to a competitive level too. Isn’t May when the CSC will release the rules we are going to use anyway? Tech issues, are always performance issues, when they are not, it’s called safety tech.Doug said:
“Let me ask you, would you spend $1500 on a PI in stock case if you knew you could lose it in a grid swap? The guy who gets the cheater box gets to go like stink! (at least for that day)”Ya you know me, I wouldn’t spend $1500 on that, but I am sure I and many others would spend it if it ment that I could make a nother PI out of the stock box I got from the previous race to try it again at the next race.
Are you tring to say that the people that can do it now are going to stop doing it? Some people buy speed and some people make speed. The people that make speed are the ones that sell speed, because they know how to make more.
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