If its gearbox oil then your crankcase seal is gone..you need to split the engine and replace at least parts

3, 11 and 12 but it would be better to replace all the seals and bearings too.

http://twostrokemoto...lding-tsm-tech/

The crankcase of a two-stroke engine is sealed from the tranny. It’s important that the two crankshaft seals be in optimum condition. One side of the crankshaft uses a dry seal and the other a wet seal. The dry seal runs on the magneto side and the wet seal runs in oil on the tranny side. When the dry seal wears, the crankcase sucks in hot air, causing the mixture to run lean and overheat the engine. When the wet seal wears, the crankcase sucks in tranny oil, causing the engine run rich and eventually wet-foul the spark plug.

Had a mechanic look at the piston and rings. Said they were good, said the CDI was no good. I don't think that's the problem but I'll try it and see what happens. What do you guys think?

But, what kind of deal do you have with him?

Meaning if he swaps out the CDI & the problem still exists will he slap yours back in & not make you pay?

Or are you having to buy all the parts as he goes through the process of elimination?

I'd suggest you eliminatre the simple options before going ahead and replacing everything, the expensive parts at that.

Drain the tank from gasohol, and disconnect the fuel pump - run premix with benzine.

If you're seizing the engine that much, it's most likely due to fuel/air/oil ratios being off.

You may find that the fuel pump is shot (it's shit anyway) - running premix will eliminate any pump issues.

Is this a recent problem, to a bike you've owned for a while, or is it a new bike that came with the problem?

I would agree with Kiske's sugestions,not to replace expensive items willy nilly.

You could try disconecting the 2T oil pump hose from the carb and plug it up ( for the time being )

mix some 2T oil in to the petrol tank 30:1 ratio ???

remove the spark plug and put a cloth over the hole then give it a good kickstarting to blow out all the accumulated oil

in the crank case ( this wont help a lot if the seals are gone though )

put the plug back in and start her up if it was just that the 2T oil pump was oversupplying the problem should now be gone

( no oil on the spark plug )

if it still fouls the plug well ( flame proof suit on ) you could try running the engine without transmision oil with the bike in neutral for a short time to proove the point.

I can't see how the CDI would be the problem.

Hi guys,

Sorry for the interruption, I don't mean to.

I'm a French Honda NSR 150 enthusiast. I got a French version of the NSR 125 which I wish to turn into a Thai version.

I think all the specs are similar between those 2 bikes, only paint jobs differ.

Here is the bike I'm looking for; Honda NSR 150 SP Repsol Prom Arm 1996

My request is: where can I buy a decal set for this bike?

Thank you in advance;

Julien

catface

Ask Brian at Sumetcycle he is very helpfull.

[email protected]

www.hondasumetcycle.com

Did you find out what the problem was, and how to fix it ??

Seedy unfortunately no, I took it too what looked to big a "big bike' shop in Pattaya on Sukhumvit next to the Cock pit. It's been there since the 11th. I took him to check the piston/rings and the crank case seals he seemed to understand. I went back in later that week he said it was all fine. Then he proceeds to tell me "cdi no good". Now I'm like <deleted> because I know that has nothing to do with gearbox oil getting on the spark plug. So since the Dec 18th he's been waiting on a new Cdi. I dont think he even checked the crank case seals though. What can you do though LIFE.

I have been following the posts here as I too have an old 150 NSR, She had over 171,000 k on her and it has seized for the first time.

Papa ran it out of oil. I did not realize the cylnder was porcelin coated, I wanted to bore mine out bigger as long as we had stripped it down. I am thinking if it is a porc. coat maybe I can get a different larger sleeve that is uncoated, it would seem logical.

What do you folks think?

Went to pick up my bike the other day and took a test ride before I was going to pay and the piston seized about 1 km down the road. I pushed the bike back and said fix it and walked off. I think the bike is a lost cause, time to start over with diffrent NSR. Anyone know of a NSR for sale?