So here is a little background info. 1987 exciter 570l/c that's sat for a couple years. Ran good when it was parked. Drug it out of the shed, mice had their way with her. Cleaned the carbs, installed new needle and seats,gaskets, and bowl gaskets. Removed the air box, cleaned. removed the fuel tank, drained and flushed, installed new filter. Tors is disconnected. Fired it up, let it warm up and seems to have good throttle response. The problem is its smoking bad. Pulled the plugs after running it a few minutes, and they are wet. Gas coming out of the exhaust. Not a ton, more like a fine mist. Floats are adjusted to spec, air screws are 5/8 turns out. Adjusted throttle free play and oil pump cable to specs. All the adjustments that I have made above have had no effect. After reading several threads on here, could it be the fuel pump?? Oil pump?? I checked the pulse line and looks good with no gas in it. I pulled on the oil pump cable while it was running to give it full oil, and I couldn't tell any difference in the amount of smoke. Anybody have any suggestions, I'm all ears. Any and all suggestions are welcome and are very much appreciated. Please Help!
A couple of bucks
VIP Member
Did ya take it out and really get to run her pretty hard? Just get some fresh fuel pulsing through the ol girls veins. Even with the fresh fuel, does it still smell a bit varnishy.
I have run it around the yard a couple of times. Had it on the jack stand idling, rapped it up to 2500 rpms, and up to 4500. Have done this several times, before and after needle and seats and other adjustments. Still smokes you out and wets down the plugs. Went to a br8es plug, that had no effect. I've ran about a 1 1/2 gallons through it trying to dial her in but no change. Was thinking about pulling the exhaust and running it straight manifold for a couple of minutes to see if the pipe is just saturated, but I'm not holding my breath......well actually I am holding my breath, every time the things running!
check your pipe.. might have obstruction from said mice!!
Seems to be breathing well with the pipe on, good throttle response, no bogging. Pulled the pipe off this morning, let it run a minute, started smoking and left fuel residue in the manifold. Any other ideas? Fuel pump? How do I check the fuel pump for proper operation? Choke seems to be working properly but I cant find any specs to check free play. Not a sled mechanic, more or less learning as I go. Thanks for the reply and once again, any ideas are greatly appreciated!
Yamaha Nutz
New member
if it seems to be running fine take it out for a good run don't be so worried about excess fuel or oil as long as you are happy with it and the plugs are not following you should be fine ......my 88 would smoke like crazy and ran great .....motor finally died after 10k miles
are the choke plungers hanging up or need cable adjustment?
I pulled the plungers from the carbs today and they aren't froze up, and move up and down when operating the lever. Seems to be functional, cold started it today, ran for 20 seconds or so, flipped the choke off and there was a noticeable difference in the way it idled. Would you happen to know what the free play is supposed to be? Took it out for a good hour this afternoon. Ran decent, didn't foul the plugs, it seemed to smoke a little less but still bad at idle. Went back to the br8es plugs, couldn't tell much of a difference. Broke the pull cord 5 minutes after unloading it, me and this sled are really starting to have issues.
Throttle Junkie35
New member
I guess I would check the oil pump cable adjustment. Does the oil consumption seem excessive?? What brand of oil are you running in it?? Some tend to produce more smoke than others.
Oil cable free play is set at 25mm. I haven't ran it enough yet to be able to monitor oil consumption yet, I marked the tank before I rode on sunday for an hour or so, and didn't see much of a change. Yamalube2s is what I'm using now. No idea what the previous owner ran, so I asked the guy at the local shop since they had an entire wall of different 2 stroke oils. Anything better out there or what you would recommend, I'm all ears.......or eyes!
Thanks, I'm going to check that tomorrow after work. I did notice that the amount of threads showing on the adjusters is different. But they seem to pull the same distance when the choke lever is engaged.
I think he means that the choke flipper should move 1mm before the plungers start to move to make shure it is seated properly.
I may be crazy, but check your thermostat. I had an issue with my Vmax where it was smoking like an SOB and plugs were getting wet. I finally figured out that it was not getting up to temp. Pull the housing off, and seen that there was no thermostat. Replaced it and it stopped acting like it was. Runs good now.
Thanks for the tip. I will look into that, hopefully this weekend. Ordered some parts for ole girl this week since I saw some signs of life out of her last weekend, now all I want to do is hide out in the garage and tinker.
