Hey everyone,
So I have been doing some work on the bike (replaced spark plugs, new coils and wires) and i decided to start it up and see what would happen. It was a little hard to start but once it finally did it had a hard time getting a good smooth idle. I played with the choke settings and all and once I got it to what seemed to be warmed up i decided to rev the motor and it just would bog down and not do much. I finally got it upto 4k RPM's but that was serious work and it was blowing white smoke out of the exhaust. Im used to working on cars so I know what white smoke typically means there but what does it mean with a motorcycle? Could it also be that I have a vaccum leak somewhere in my lines?

 

White smoke means the same on a bike, coolant or moisture if it's been sitting awhile. What did the old plugs look like? Did one look different than the others, like it may be burning coolant? If the radiator builds pressure quickly, I'd be looking at the head gasket.

 

Thats what i figured, i did pull the coolant cap and noticed that the coolant was nice and green, and looked fresh. I think that maybe i have a clogged thermostat or clogged line, because i have no coolant in the overflow tank. When i pulled the old plugs they all looked the same dark at the end, looked like maybe the bike bad been run hot... not too sure. I cant ride it yet, still working on a title issue but shouldnt take long.. any reason that its bogging down? It was struggling hard to build revs, should i run some cleaner through it. I figure it cant hurt anything.. of course it could always be a vacuum leak too. Who knows explorative surgery is always helpful. Thanks for the help in advance and thanks for the advice thus far!

 

If you're leaking or burning coolant through the engine that would also explain the empty overflow bottle. It will empty the reservoir first before you start losing coolant in the main system if everything is functioning properly. Is it constantly producing white smoke while running or was it just that one time that you were running it?

Did the bike run ok before you started having these problems or is this the first time you have got it running? The bogging and running poorly problems could be as simple as dirty or misadjusted carbs, but the white smoke is definitely not normal even if it was running very rich or lean.

Might be a good idea to do a compression test on the engine. If the head gasket is blown or head warped bad enough to run like that it should be pretty obvious looking at the relative compression between all 4 cylinders..

 

Thanks for the reply, It doesnt constantly smoke when under throttle, just that one time. I have had it "running" before but nothing over 3k rpm and it was always sluggish to get there, i always just assumed that it was that I didnt allow it enough time to warm up. When i got the bike the guy i got it from ran it and it seemed to be running well, I am pretty naive about motorcycles, being that I am a car guy. I think I will do a compression test and see what happens, or since i have to have some new tires mounted on it maybe ill just have the mechanic look at it while its in the shop. I hate to say that but it wanna get it on the road again for the first time in like 7 years.

 

If it's been sitting for 7 years I would almost guarantee that the carbs are varnished and the jets are plugged up. Those are pretty common symptoms of dirty and/or out of sync carbs with the bogging down and having trouble revving to higher rpm's.

If it isn't constantly blowing white smoke it's probably not a head gasket issue.. the engines on these bikes are pretty tough unless you overhead them badly. But any aluminum engine that's overheated badly isn't going to like it

If it were me, I would pull the carbs and disassemble & clean everything out really well, and sync them after getting it back together. Maybe also reset the mixture screws if there is a possibility they could have been tampered with. Carb sync is very important with 4 individual carbs. Even if they are clean if they're far enough out of sync w/ each other the bike will never run right.

 

sound advice! I think I will pull the carbs sometime soon and clean them, i called a few shops and asked how much they would charge to do the job and 325 was the lowest I got a quote for. I honestly think that I have figured out the white smoke. I just cleaned and re-oiled my K&N filter and i let it dry out for a day but i think maybe some of the excess oil may have gotten into the carbs and caused the white smoke. Either way i ordered a new thermostat and I am going to replace that when I do all the fluid on the bike change out.

 

The carbs are pretty easy to clean.. you don't have to completely disassemble everything just pull out the whole assembly then you can remove the float bowls and access the jets. Clean the bowls & jets out real good and blow compressed air through all the jets to get any junk out that's stuck inside.

I had the same problem when I re-oiled my uni foam filter awhile ago, but not sure if it was making white smoke or not. Definitely ran like crap after sucking some of the oil into the carbs though!

 

so i did more work today, and i figured out that the filter wasnt what was causing the white smoke. I took the filter assembly off and ran the bike and it still smoked, so i looked more closely at the carbs and they had what looked like oil on them, so im gonna look for a used carb set, i honestly think something is wrong with my carbs, and dont feel like messing with, i am having one problem, how do i get the throttle cable off the carbs? I couldnt figure it out, and probably spent 30 minutes trying to get that off.

 

The oil may just be varnished gas and junk leaking from the seals from sitting.. you can probably also pull the carb assembly out and have a shop rebuild it off the bike for less than buying an unknown condition set of used carbs. Just a thought..

As far as the cables if I remember correctly you have to back the nut off each cable to where you can slip it out of the bracket at the non-threaded part that is thinner. Then you can rotate the butterfly and slip the cable out. I might be wrong as I'm going by memory here, but you can also download the service manual from the sticky post in the forum & it should have the info as well.

Feel free to ask any questions you may have.. I've rebuilt my bike from the frame up and many other members have good info to share as well.