Hey KNOWSALOT or any one else, I'm putting my '86 lt230s top end back together and I'm not sure about a couple of things. Came back from a long ride a few weeks ago, unloaded, cranked up and it was smoking like a mosquito fogger! It got worse after a short ride around the yard, but ran and sounded fine. So I tore it down expecting to find a broken ring, grooved cylinder wall or something like that. Looked really good. Machine shop checked it out and everything was within spec. Piston measured 2.596, bore measured 2.5985 and was not egged out at all. Stock bore spec is 2.598. Everthing else looked very good and clean, checked with original owner and this is the first time the engine has been apart! I went ahead and told the machinist to do a valve job and 1 of the valve seals was a little mushy but intact. I also ordered a new stock piston/ring kit in std. bore size. Two questions, is there anything that might cause this motor to smoke like that so suddenly? It never smoked before, and looked to be in such good shape internally. Oil down the guides? Don't want to put this back together and overlook something. This is my first quad or bike motor I've ever worked on. Done dozens of automotive engines and always found a smoking gun upon teardown. Not on this one. Also I ordered a K&N with outerwear to put back on it. Will I need to rejet at all? Exhaust is stock. Any help will be greatly appreciated.

bobcatv8

 

It sounds pretty much like you covered everything already.

You said that you unloaded it and it started smoking. Did it not smoke when you loaded it up the last time you rode?

Did you do anything to the machine between the time you loaded and unloaded it? Did you change the oil? Anything at all?

Sounds puzzling if you answer no to both of those questions.

In all likely hood, since you covered all the basics, I would assume that the valve seal was the problem. They don't always cause problems gradually. It could very well be the valve seal.

Did you check to see how much compression the engine had before taking it down? If so what was the reading?

As far as your jetting question is consered. No, installing the K&N with outer wear will not necessarily mean that you have to rejet. Especialy with a stock exhaust. Just be sure to use your airbox lid. If you don't then you may have to re-jet. Do a plug check after you put it on.

Let me know how your engine does after you get it back toghether. Oh,..and don't put the K&N filter in until you get everything back together and in running order.

 

Thanks,KNOWSALOT. I rode it pretty hard that day and the weekend before too. I was keeping up with bigger, newer quads with lighter, more experienced riders on board. I was guttin' it pretty good. Did not smoke at all during the ride or upon loadup. About 3 hrs between loadup and unload. Oil level was fine, 10w40 honda 4-stroke oil used. Was getting close to oil change time though. Is the .025 piston to wall clearance about right? Top 2 rings gap was .011 upon disassembly, sound about right? Machinist is putting a cross hatch pattern back in the wall without adding clearance, good idea? I did not take a compression check, I just assumed the worst and tore it down figuring with its age and all. The engine was the only thing I had'nt gone over on the quad. I really appreciate your knowledge and quick reply! Thanks.

bobcatv8

 

You must re-crosshatch a cylinder anytime you replace the rings to remove the glaze and give the rings something to wear into. Usually it's just a cheap cherryball type hone. Just a handfull of passes is all it usually takes.

Without a manual .011 doesn't sount like much wear for the compression and scraper rings. Check it up and down the cylinder wall to get an idea of the overall wear. Ususally the oil ring will visually show wear on the 2 ring surfaced. All that dirty oil will flatten them out.

I've got an old 230 that's doing the same thing. intermitting bug fogger. Still runs and starts ok. Just a pain to be behind.

Did you have to pull the engine or just the top end?

Good Luck,
Rob

 

Thanks Rob, got a new std. bore piston and ring set coming, when it gets here we will fit it to the cyl. at .0025 clearence. Machinist said the walls were in great shape, needed no more than a new crosshatch finish to reassemble. Bought the new piston because it was part of a kit, since I've gone this far, why not? I went ahead and took the motor out of the frame, it was a snap. Had it out in 1 1/2 hrs. I wanted to clean & inspect everything and replace as needed. I think you could pull the head on the quad, but not the cylinder. After messing with cars all my life, these quads seem easy!! I could not find a connecter for the 6 wires going into the case so I cut them. That was the only thing that I did'nt like about the job. I guess I'll get weatherpac connectors to put it back together with. My machinist said the same thing as KNOWSALOT about the valve seals, and also said possibly oil drainbacks might be partly plugged and slow, causing oil to puddle up top and suck down the guides. Got new seals from local Suzuki dealer and valve job is being done. I've got the engine out but I'm not going to get into the bottom end at least not now. Don't be shy about pulling your Q-sport down, it really is an easy quad to work on. Those long head studs will probably prevent taking the cylinder off in frame. I'll have it back together in a week or so. I'll post back how it came out! thanks for the replies!

bobcatv8--rookie Suzuki mechanic.