I recently acquired an 86' LT230S which was in rough shape. It was ticking loudly. A friend of mine helped me install a new oil pump.. it had been running dry for some time. Someone forgot a shop towel in the clutch cover.. Anyways its got a new oil pump and still ticks, not as loud, but ticks. Rockers and cam are scoured moderately, so I went out and bought a wiseco .20 over got jug bored to match and hotcams stg. 1 cam. I know I need rockers but I'm not sure what else to get after. The exhaust valve looks like chalk/very very light brown. I'm assuming this means its either leaking or its been running lean since forever?. I was always about the two strokes and would like a reliable 4s for all-season riding.

I also was wondering if anyone has done a Mikuni TM carb (flat-slide). It was a night and day improvement on my two stroke 250 /w oil injection (same plug for 2 months so far - starts 1st or 2nd kick)

 

Left a shop towel inside??? lmao! A few guys I know of around here have a 28mm flatslide (including me). One or 2 have a 32mm (not sure if flat or not). I agree about the night n day improvement,,, mine runs like a 2-stroke since the new carb. I had all kinds of problems getting the jetting right with the new carb though (I still have a rich idle and just above idle). I think the 28 is slightly on the big side for the little 1/4 liter engine, but it will work. You should take your head n valves to a shop for them to check the guides, springs, and see if you need new valves. I doubt it would cost even $100. You might be right about the lean condition, not sure, but with a shop towel inside nothing would surprise me at this point. [img]i/expressions/face-icon-small-smile.gif[/img]

 

JustRandy: what you got for a main and pilot? Did you buy the carb off of like bikebandit and swap jets?

 

Yeah, I got it from bikebandit. I drilled the jets with numbered bits (ie #57, #58, etc). It makes things easier for me since I start with a small jet and gradually get bigger until I hit the right size. I don't have to worry about keeping a lot of jets around either, even a piece of brass with the right threads will work, lol.

 

Oh, I forgot to talk about porting. I haven't ported mine yet, but a couple guys here have, who knows if it helped or not. I was talking to a guy at Vince Cycles http://vincescycle.tripod.com/newparts/lt230s.html (didn't catch his name, but I guess it was probably Vince). Anyway, he had done a lot of flow testing the 230 back in the day and told me that porting makes negligeable difference in flow. I don't know what kind of porting he did though, but I assume since he used to build race bikes he knew what he was doing. He also told me any cam with a lift over .280 is a waste and will just beat your valvetrain up for no reason. He recommended no higher than a stage 1 cam for this reason.

Come to think of it, do you have the specs on the hotcams stage 1 cam? I emailed the guys that sell them and I don't think they know what they are doing. They gave me some 300 something duration on the exhaust and that is just WAY too much for a stage 1 cam. Its too much at .050 lift for my software to accept. You simply can't simulate that duration. I think there is a misprint and was wondering if there was anything that came with your cam that has the specs.

 

U should check the connecting rod since that is supplied thru oil passage in clutch cover. It would be good idea since u had past oiling problems. I know the carb i have uses same style jets as the stocker but not same size. Ill have to pull the bowl on of these days and see what jets im using.

 

I would really really appreciate it if you could tell me the jetting specs you have on your TM. and the needle too.

 

It's good now, the valve inspection cover was leaking oil. I still have the jug apart, its being matched to the piston at a machine shop. I just was hopeing someone had jetted this thing on a TM before. Maybe 24 is the way to go for these.

 

24??? What do you mean? Do you have the hotcams stage 1 specs?

 

I'll check it out when i get home.

BTW if you convert the drill bit u use to mm it = the Dynojet #. So eg a 1.81mm jet hole = DJ180. Charts will convert DJ180 -> Mikuni #210..(mikuni is based off flow rate).

How is 1/8 to 1/4 if you blip the throttle or launch with that needle/idle combo?