A few weeks back I picked up a very neglected 1996 LS650 (6000ish miles). The major issues were as follows:

- The bike had not been started in at least 6 years, and sat inside a shed (yay), under a tarp (boo).
- A critter ate the main harness under the tank, and the tank wiring. I swapped the main harness out for a 1998 one, that is all fixed. I also fixed the tank wiring myself. All is well there.
- The gas tank was full of 1/3 gas, 1/3 murky water. I completely drained that out and flushed out all the crap I could. There is a little rust in the tank, but not a worrying amount.
- Airbox had a lot of oil/water in the bottom of it, air filter was toast because of that. I removed the filter entirely (a new one is on order). Everything was cleaned and re-installed, except the filter which we left out for testing purposes.
- Engine oil appeared to be empty. In actuality the case was full of oil AND fuel. I drained the engine and put back in the proper amount of 10w40. All good here. And no, we never tried to crank over the bike with all that crap in it, thankfully.
- The jets in the carb were completely stopped up with gunk, and the float was covered in goo. I cleaned everything out, and got as much out as I could. The slide and diaphragm also appear to be in good shape, no tears, good seal on the diaphragm, needle was pretty clean. Overall the carb appears to be AOK inside now.
- With fresh gas in the tank and the rest of the issues sorted, we tested the petcock. No fuel flowing on the PRI setting, or any other setting (with vacuum). I'm not surprised. We grabbed a little fuel bottle and used that as our gas tank instead. Raptor petcock on order.

With the tiny "tank" hooked up, the bike fired right up and idled after two attempts. Not bad. No evil noises coming from the case (I'll check the cam tensioner soon to verify). Sadly though, whenever we touch the throttle at all the bike chokes out and dies.

At this point it seems like a carb/fuel issue. I'm guessing two things:
1.) The little bottle we were using as a "tank" wasn't flowing fuel fast enough. Maybe the raptor petcock on the real tank will help?
2.) There is still some part of the carb that is gummed up that I didn't get to. Any ideas where else I should look? I didn't check the TEV part of the carb, should I? Is there a total carb rebuild kit I can buy?
3.) Would the auto decompression system cause this? Could it be out of adjustment? This is a shot in the dark.

Thanks for reading LS650 experts! I'm hoping someone can point me in the right direction.

S-P wrote on 03/14/14 at 07:19:51:


That's what I'm thinking. I got the float area and the diaphragm area very clean. I'm just not sure about some of the smaller passages. I also never removed the pilot air jet or the other air jet (main air jet?). Maybe there was gunk in there too.

You definitely need to take the carb main and pilot jets out and clean them, along with the little passages in the carb body.  To do this properly the brass cover over the idle mixture screw will have to be drilled out, and the idle mixture screw removed.

There is an article in the Tech Section showing how to take a carb apart and clean it.
http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1191899985

I have never taken the jets out of the TEV or top of the carb body.....it is most likely the jets down near the float bowl that are causing you problems.

Running without an air filter can upset the air/fuel mix. This might be contributing to the off-idle stalling.

Just take it apart, you wont miss any rubber.. its not that complicated, theyre just finicky, & make sure the gas ya go back with is fresh, just regular gas,

there is an o-ring in the float valve seat.

interesting to note, the carb specs diagram does not show the idle mixture screw.  And supposedly, there might be an o-ring in there to hold the adjustment.

You said "bottle" for your temp gas tank.... did you vent the bottle?

Even if the bottle flows slow, once the float chamber fills up, you should be able to rev it higher than idle for a short while.  At least until until the float level lowers too much.