Porting

[VintageBlueSmoke]

Actually the porting  and exhaust valve mods are designed to fix several problems with the 2001 CR125 motor. Read the budget racer project these guys did. The bike is a turd, It has no top and and takes forever to wind up. Its saving grace is a killer chasis and good suspension. I picked it up for 800 bucks, this is the last thing that I have to tackle. Its a dog, so yes, it will lower my lap times. Every other 125 I owned used to light up with a dab of the clutch, this thing does not. And the jetting is right on. So its a matter of fixing the flaws on the bike.

Read here to see what I'm dealing with..

http://twostrokemotocross.com/2009/05/budget-racer-2001-honda-cr125/


You say your not hating but How could you possible make such a statement without knowing about my bike, or my riding ability?

Over 40 years of riding, racing, testing and training...that's why. Look, I can tell you are not a school boy A125 rider because you are trying to improve on an $800 eleven year old bike. That is admirable. And there are many things with that model that can improve performance. However, you are looking at an expensive job, a job that you are considering doing yourself because you read it in a magazine. Rarely is a (relatively) modern motocrosser a "turd" when tested by the magazines. All the bikes are so close in performance that they (the testers) have to pick at hairs to differentiate them. Keeping everything fresh is expensive enough without adding half the cost of the value of the bike to it. Your lap times would fall twice as far if you took that money and spent a weekend with a trainer or at an MX school.

And that you can take from bike to bike.

It's your money (and your cylinder). Part with them if you want. I am just passing on advice to improve performance. Something you solicited.

[dbroc78]

I appreciate the advice, maybe it was your delivery.

funny thing about the Budget racer article is that they described the performance of their bike before the mods and it is identical to how my mine is performing. Then I got a news letter from Eric Gorrs website about specific Mods for my bike.

http://www.eric-gorr.com/pdfs/modeltuningtipsHondaCR.pdf

The Eric Gorr letter contains the same mods HP did in the Budget racer article which didn't come out of a magazine, it was a project produced by Twostrokemotocross. At this point I figured it was legit, wasn't just going off what I read in a magazine. 2 sources confirming the same information.

Unless there is something else seriously wrong with the bike I don't know what else to do. I've been riding and racer for 20 years and it is by far the slowest 125 I have ever ridden, honestly man its like i'm dragging around an anchor.

so my initial investment was 800, and the thing is restored to near perfection except for the power issue. I sure as hell won't sell it, i have my heart and soul poured into the thing. So getting the head done so the bike can perform so I can do some local races again sounded like a great idea. Maybe I was wrong.

And the bike has a fresh top end, 5 hours on it maybe.

[VintageBlueSmoke]

Yes, I admit I come off a little strong sometime. For that I apologise.

I know a lot of people complained about the CR125 but I for one liked it. Once I got the clutch issue sorted, it was pretty easy to ride especially is the slipperies (logs, roots, clay, etc). I know what you are saying but I set one up for one of my friends (competitors). I didn't notice it being any slower (lap times - not feel) than my stock '01 YZ and it had some really appreciative qualities. I really liked the suspension straight out of the box; the YZ needed springs and valving. I wasn't doing supercross style jumps in '01 but ravine and creek crossings along with smaller doubles were no problem. If I remember though, we wasted a lot of clutches.

[dbroc78]

I love the suspension and the handling for sure. At the rate i'm going I could see myself smoking a clutch in no time. Someone mentioned to me about exhaust valve maybe not operating correctly. Thats next on the list.

[Super Trucker]

I remember that budget 01 cr125 post,didn,t they split the cases and stuff the cases. I asked my motor guy about stuffing the cases,when I moded my 04. He said the pre 04 benefit from stuffing the cases. I,m not sure about going that route tho,the engine guy better have experience stuffing cases. Sounds like you want to send it to Eric G.,his info matches the budget racer info. So I would send it to E Gore, alot of people know the name, that will help if you ever want to sell it. I,m not up on 01 cr125 hot mods, I do know there,s an aftermarket ignition avail. in USA, last year for the cr125. I would go with a pc pipe,if your looking to get a pipe. I wouldn,t overborre,the gp wiseco piston 56mm is heavy-slow responding,great piston tho. The 04-07 have thin exhaust port bridge,when over borred, not sur about the 01. I would port for mid to top,borre carb,pipe if needed, etc.

[dbroc78]

They did split the cases, thats one deal that I am shying away from. You can either build up the case for low end, or build up the head for top end. At least that what Eric Gorr is telling me. I have an FMF SST pipe on there now, well, it came with it. Not sure about how that pipe racks up. I found a few other cheaper mods that deal with the exhaust valve and the exhaust manifold. Using the 2002 parts are supposed to help with low to mid range power, which is where I am getting murdered. This is all from the Eric Gorr link that I posted earlier in this thread. going to work with these before I decide to port it, Top end is brand new anyways.

whats the deal with the ignition? First time I have heard of it.

Thanks for the advice, I really appreciate all the feedback.

Dave

[Super Trucker]

Pc has a jd ignition for the 00-01 for 100 bucks,can,t beat that. I would sell that sst pipe,always heard that pipe takes forever to come on the pipe,very slow response,with no increase anywhere. Put the stock pipe on,or get a pc or hgs if possible. If low to mid is where you want an increase,get the radvalve,you don,t have to get a 05-07 intake boot then,which is the best,but not sure if it fits the 01 or not. Remove reeds then polish all the inside smooth. In 06or07 one of my pals raced a 01cr125 in b class,totally stock everything,he was 1st in the northern cup series.He was never out of the top 5 in overalls,he was prob 170 lbs.then,never made mistakes tho.He just rode the bike in the strongest part of the mid.

[dbroc78]

wow great info man. Maybe its that pipe thats killing me? I'll look at replacing that pronto! I already put the 05 boot on, fit like a glove. I am planning on an aftermarket valve this winter and I'll most definitely look at that ignition.

Thanks again!

[dbroc78]

by the way by ignition to you mean the whole set up? coil and all? or just the CDI box??

[Super Trucker]

Just the cdi box,it,s a jd ignition,I never used a jd ignition,but at 100 bucks it,s cheaper than a icat. The jd ignition is on pc,s website. There,s a cool vid on youtube oca-helmetcam-cr125-brappp, of a yz250 chasing a 01 cr125 blackfoot ex pro bike,deff a upper mid-topend motor,sounds awesome.

[dbroc78]

cool i will check that out! I had the RC valve apart this weekend. Turns out whoever had it apart last was a hack. The linkage was all jacked up, wasn't working correctly, if it was working at all it would have been a miracle! Waiting for some seals to come in, Looking forward to seeing how it runs now. At least this explains why it was such a dog!