Honda CR125 - What else for I need to make it run?

Tim Salvino · Joined: 20 Nov 2010 Posts: 258

Anything other than a "Stock" 1999 Honda CR125 (obviously its not 100% stock) would run as an Open Moto. In most places they would just be grouped as Open Shifter.

There are really only 2 sanctioned shifter classes in the US. Stock Moto, and ICC/KZ.

Stock Moto is, as we already discussed, ONLY "Stock" 1999 Honda CR125.
ICC/KZ is for purpose-built, european 125cc shifter engines.

Brian Degulis · Posted: Tue Oct 09, 2012 1:23 pm Post subject:

I understand the 6 speed transmision now was that only produced in 99 I thought it was up to 99?

Ceasar you mentioned earlier that you wern't interested in getting into racing right away. Why not get a 99 CR25 dirt bike with a running engine then take the engine off buy the parts needed to get it on a kart and use it. You'll get to see if it suites you and how it all works out then if you want to compete just get that engine built or buy the hot set up and use your conversion parts.

Like you I'm new to this and for me laying out 4K for the best right from the start on something your going to put together yourself may not make sense. As long as you start out with the right engine what diffrence does it make if it's not producing peek power as long as it's capable of it down the road.

Just a thought.

Brian

Tim Salvino · Joined: 20 Nov 2010 Posts: 258

From SKUSA rulebook:

"Five (5) speed as originally delivered in motorcycles or six (6) speed available through Honda in kit form. The six speed transmissions must be 1994-96 OEM components. All transmission components must remain OEM."

Cesar Rull · Posted: Tue Oct 09, 2012 2:09 pm Post subject:

^

20.3.2.6.1. Approved engines: The 1999-2002 Honda CR125R

20.3.2.6.4. Cylinder: 1997 to 2002 cylinders are legal. No
modification of the cylinder is allowed, such as porting,
adding or deleting of ports, decking, or re-nikasil. Stock
power valves may be removed and aftermarket plugs used,
with no filling, welding, or modifying of the cylinder. No
machining of any portion of the exhaust port is allowed.

20.3.2.6.9. Transmission: Five (5) speed as originally delivered in
motorcycles or six (6) speed available through Honda in kit
form. The six speed transmissions must be 1994-96 OEM
components. All transmission components must remain
OEM. No aftermarket parts are permitted.

20.3.2.6.13.1. CDI: Must be OEM 1999 with no modifications to
internals or wiring.

So basically, the only things that need to be '99 are the CDI.
This is good news, because it gives us a bit more room to shop.

Cesar Rull · Posted: Tue Oct 09, 2012 2:16 pm Post subject:

joseph hollinger · Posted: Tue Oct 09, 2012 2:32 pm Post subject:

Brian Degulis · Posted: Tue Oct 09, 2012 2:43 pm Post subject:

Yeah I got it I thought the diffrence in money was much greater.

What is the diffrence in HP between stock Honda and ICC ?

Brian

Cesar Rull · Posted: Tue Oct 09, 2012 5:30 pm Post subject:

Unless you have a dirt bike mechanic who can work on your engine you should be ok. I think any qualified dirt bike mechanic can rebuild and tune a cr.

For example, I can get a 2004 motor not working for 200 bucks , the mechanic tells me he can make it work for a few hundred... in the end I could have a motor for less than 1000 to get me driving in the beginning.

Its true, Im not going to lie I would love to buy new but i don't have 4K. Plus I have a long way before I can get into SKUSA or any racing for that matter.

Cesar Rull · Posted: Tue Oct 09, 2012 6:26 pm Post subject:

If I were to buy a working CR125R after taking the motor from the bike, what modifications do I need to have a mechanic make for the engine to work on a gokart.

Is this something feasible? / documented somewhere?

Tim Salvino · Joined: 20 Nov 2010 Posts: 258

http://metal-matrix.com/stockmoto/index.html

Troy V Smith · Posted: Tue Oct 09, 2012 7:13 pm Post subject:

Cesar - I think much of what you are asking is going to be based on what your intent is. If your plan is just to attend club level/weekend racing, then i think you'd be ok with just about any CR125 brought up to kart standards. If however, you are looking at getting into the serious, upper levels of competition, you might look at investing the cash for a premium motor.

I really don't think you need a mechanic to build or work on a CR125. They are not that complicated or complex. I fyou can read and follow a manual, you can rebuild a CR125. Only a few tools you'll need to do it proper and they are not expensive. Again though - if you intend to get into serious competition, you may want to spend the bucks for a motor builder - which needs to be kart specific - not your local honda dealer. Huge differences in the performance requirements of a dirt bike and a kart.

No real "mods" are required - most of which will need to be replaced is pretty much a smiple "take out, and drop in" approach. The articles on Fastec site are pretty cut and dry as to what is required.
_________________
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"We may not be the fastest on the track...
but we're having the most FUN!"

Cesar Rull · Posted: Tue Oct 09, 2012 8:02 pm Post subject:

Thank you. I will look at the fastec site.
You are right, for know I plan to run at club level. I just want to get seat time.
So getting a true 99 is not important. It is ideal but not important.

Cesar Rull · Posted: Tue Oct 09, 2012 9:59 pm Post subject:

did some careful reading of the article and learned quite a bit.
I have a question about the SwedeTech O-ringed Power Valve Plugs. Do they only fit a '99 cylinder?

what is the difference between a CR from '99 and a CR from 2004 for example? I ask because many of the part of some of these site say '99-2002..

Aaron Bunch · Joined: 30 Jul 2012 Posts: 19

I suspect what you are reading about 1999-2002 refers to what total year range is "legal". The 1998 and 1999 cylinders are identical. The 2000-2002 cylinders are identical (but different from the 98/99 cylinders. The power valve setup for the 2000-2002 cylinders is different than the 98-99 cylinders. I think SRS's page explains the differences in more detail.

I just replaced the top end on my 99 stock moto CR125 motor and bought power valve plugs from Shark Shifter. I was kind of worried because I know you can't blend them in place for fear of touching the cylinder, but the Shark Shifter 98/99 Power Valve plugs fit almost perfect. I think I spent only about 120 seconds with my dremel making them as good as I could get.

Aaron

Cesar Rull · Posted: Wed Oct 10, 2012 7:02 am Post subject:

Do you guys anything about a 2004 cylinder head / motor?
The motor came from a kart but I wonder if was properly plugged etc. The way it sound it seem like I will need to buy a new cylinder and I wonder if I can use a 1999-2002 cylinder on it with a matching piston and the swetdethech power plugs.