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TTR Ignition Timing


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Well, I did a seach, and their really isn't much info out there for TTRs, infact, I only found one member that did it, and he didn't really post any in-depth results. I just bought the wife a TTR 125L last year. It is a great little bike, and she has had a lot of fun on it. I have already done the airbox mod, played with the Jetting, and made my own exhaust tip for it. I assume the bike came with fairly retarded timing from the factory to comply with BS emissions standards. I want to know if anyone has advanced the timing in the little bikes, and if so, was it a noticable improvement? If you did advance your timing, how much did you advance it, and how did you do it?

Thanks for the input...always in search of the extra power!

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i have a situation where i feel like my timing has jumped? it bangs out on 3/4 to full revs. happened when putting in hot cam. now stock one was put in at race track sat morning and bangs with it. do you have any advice? rejetted no help plug looks perfect. runs good just no hp on top. even tried my cdi on a perfect running ttr, no banging out. this bike has only 8 hrs on it. started banging at 4 hrs. about timing? who makes an internal rotor for ttr125? we race with street tires on gokart tracks. i want all the hp's i can get.

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Yes i've done it. Can say that it has helped. RPM's jump up quicker, more noise, a bit more power, more bottom end, a bit more heat in the motor. It's kinda a sketchy mod since there is no real way to measure the advance. Here is what i did. Pop open your flywheel cover. Locate the timing pick up. It's held in place by two allen head bolts. On the timing pick up mount you need to cut sections out where the allen bolts hold it in place to allow you to slide the pick up towards advance. Slide in in the oposite direction the flywheel turns this will advance the point in which the pick up meets the timing mark on the flywheel. You wont be able to move it much, i probably got it to slide/advance 3-4mm. I always run premium or race gas just to make sure the motor won't detonate. I've ran it this way for over a year and have alot of hours on the motor with no issues, track and desert riding. Good luck.

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PS

the best mod i did was to port the intake and head. The head is the limiting factor with these bikes very poor air flow. I opened up the intake port, smoothed the bowls, and opened up the exhaust port quite a bit. This combined with the BBR Cam and 150 kit realy brought out some power. The second best mod i did was an experiment with a CRF230 carb. I was certain it was going to be over carbed but the CRF230 carb fixed the flat spot off idle i had with the BBR carb and also gave the bike much more power across the curve. I can do roll on wheelies in 3rd and with a little pull get it up in 4th. Next i'm going to try milling the head to increase compression, i'll let you know how it goes.....

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Thanks rdahl! What did the 150cc kit cost you? I haven't really given much thought to putting a big bore kit on it...I just planned on keeping the bike a 125cc for reliability issues...I am starting to consider a Wiseco 11:1 piston though. Porting the head sounds like a good project, I modified the stock exhaust - pulled the spark arrestor/tip out and built my own. I also smoothed the inlet to the pipe - ground the weld off and rounded the flange into the pipe. I don't think there is much to gain from an aftermarket pipe over a modified free-flowing stocker...not $250 worth anyway. I have a Mikuni VM26 carb I am going to be working on jetting here soon. I have heard good things about the CRF230 carb...what is your elevation, and where do you have your jetting set? I will look into advancing the timing per your method...I figure the thing came with fairly retarded timing from the factory for emissions standards.

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Four Paws,

I bought the 150 kit from BBR i believe they're running around $400?? If you go with the high compression Wiseco let me know what you think. I'm not sure but i think the BBR kit is only 10:1 compression.. If you port the head, google head porting tools. It's well worth $50-60 to get the Porting Kit, makes the job a piece of cake and real enjoyable. O and you'll deffinately need a spring compressor to take out the valves. I made my own which i don't recomend, probably cost me 3 hours of tinkering by not buying or renting a real spring compressor.

I'm here at Sea Level and don't remember where i set my jetting. I know with the Mikuni VM26 i would always get bobbles durning G outs. With the 230 Carb i never get any bobbles.

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Rdhal

Reading the threads was very interesting, was that CRf230 Carb easily attaches to the rubbler manifold that the TTR125 has???? Did you have to play with the Jetting to dial it in to run like you said??Like to do that to my TTR.

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The CRF 230 Carb isn't a straight bolt in. Yes it does fit to the intake boot. I'm not sure about the airbox boot since i have removed my air box and run a sock style filter. The Carb is very tall so i had to run a foam spacer under my fuel tank to raise it .75". Only now the seat bends up slightly more than before. I honestly can't remember what i did for jetting. I want to say i'm running a 120 main??? If i remember i'll check tonight when i get home. I was very impressed with the performance this carb gave me over BBR's kit. The carb was somthing i found on Ebay and pretty much stole it for $50. I'm pretty sure i have pics somwhere. I'll post them if i can find them.

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The CRF 230 Carb isn't a straight bolt in. Yes it does fit to the intake boot. I'm not sure about the airbox boot since i have removed my air box and run a sock style filter. The Carb is very tall so i had to run a foam spacer under my fuel tank to raise it .75". Only now the seat bends up slightly more than before. I honestly can't remember what i did for jetting. I want to say i'm running a 120 main??? If i remember i'll check tonight when i get home. I was very impressed with the performance this carb gave me over BBR's kit. The carb was somthing i found on Ebay and pretty much stole it for $50. I'm pretty sure i have pics somwhere. I'll post them if i can find them.

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Four Paws,

I bought the 150 kit from BBR i believe they're running around $400?? If you go with the high compression Wiseco let me know what you think. I'm not sure but i think the BBR kit is only 10:1 compression.. If you port the head, google head porting tools. It's well worth $50-60 to get the Porting Kit, makes the job a piece of cake and real enjoyable. O and you'll deffinately need a spring compressor to take out the valves. I made my own which i don't recomend, probably cost me 3 hours of tinkering by not buying or renting a real spring compressor.

I'm here at Sea Level and don't remember where i set my jetting. I know with the Mikuni VM26 i would always get bobbles durning G outs. With the 230 Carb i never get any bobbles.

www.mx-performance.com has the bbr 150 bbk for $400 thats what it cost after shipping and handling

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