GZ250 Smokes on cold start, stops smoking after running

[DBG]

My bike spews blue/white smoke every time i start it after letting it sit a while. After a few minutes, the smoking stops and it purrs like a kitten. I've done some research on the issue, and it looks like it might be a sticking valve or worn valve seals causing oil to drain into the cylinder after i kill the engine. Then upon start up the oil that drained into the cylinder burns off in a cloud of ninja smoke. I ordered some new valve seals and plan on replacing them later this week. I'm also going to soak the entire cylinder head, inner block, etc., in Seafoam to get rid of any excess carbon. If this doesn't fix it, I'll move on to checking the cylinder walls and piston fit, etc. (engine has good compression already). If anybody has any suggestions, send em my way. I plan on posting the results once all is said and done.

[alantf]

I'll move on to checking the cylinder walls and piston fit, etc. (engine has good compression already).

If you've got good compression, I don't think that piston fit would be the problem. :)

[Road_Clam]

My bike spews blue/white smoke every time i start it after letting it sit a while. After a few minutes, the smoking stops and it purrs like a kitten. I've done some research on the issue, and it looks like it might be a sticking valve or worn valve seals causing oil to drain into the cylinder after i kill the engine. Then upon start up the oil that drained into the cylinder burns off in a cloud of ninja smoke. I ordered some new valve seals and plan on replacing them later this week. I'm also going to soak the entire cylinder head, inner block, etc., in Seafoam to get rid of any excess carbon. If this doesn't fix it, I'll move on to checking the cylinder walls and piston fit, etc. (engine has good compression already). If anybody has any suggestions, send em my way. I plan on posting the results once all is said and done.

How many miles are on your engine ? Sounds like a bad valve seals.

[Water Warrior 2]

How often and how much oil do you need to top it up ??

[DBG]

Still waiting on the valve seals to arrive. Yeah I read some "mechanic" on an alternate forum say that if your engine is smoking, you have bad piston rings and should immediately replace them to avoid catastrophe. This sounded more like chicken little than sage advice, and I figured I'd put my case up for posterity. My impression is that it is the valve seals (and I get the impression that you guys agree) because the bike runs great and has good compression. Also I would fix them first anyways because it's a $10 fix.

The bike barely consumes any observable oil. I can't even see a change through that little window, but it smokes a little bit on start up. 8000 miles on the engine. Thanks for the comments. I'll be sure to give the results when I get the seals replaced. By the way, any tips on getting in there and replacing the valve stem seals would be greatly appreciated. I got the manual, but would also abide any advice.

[Water Warrior 2]

The bike runs well and has good compression. Little to none oil consumption ! Could it just be moisture build up from a parked situation and then a burn off of the moisture. All it takes is condensation in the exhuast system and it goes away as the system warms up.

[Road_Clam]

Yeah I read some "mechanic" on an alternate forum say that if your engine is smoking, you have bad piston rings and should immediately replace them to avoid catastrophe..

This is not a true correct comment. There is different types of "smoking" issues. There is different suspect components.

When your engine only blows a small amount of smoke out the exhaust after startup but then the smoke stops, you have a bad valve stem seal(s). If your engine smokes most all the time under acceleration then you have bad rings. The reason your bike only smokes for a short period is that while the bike sits in between rides the oil is dripping past the valve stem seal into the cylinder. When you fire the bike up, the combustion is also burning off the accumulated oil in the cyl. Since the leak is very minimal, after about a min your engine has burnt off all the residual oil and is now running clean.

[mrgz250]

do it right 58k now going on 80k tear it down needs valvs seals & if u ge down futher you may see more parts waren out cam guides carb oring to head I was lucky I had a crack in the spark plug hole so what i did took every thing down to the base & build it back up with factory parts thats how its done the the right way even a new clutch & stator

[Water Warrior 2]

do it right 58k now going on 80k tear it down needs valvs seals & if u ge down futher you may see more parts waren out cam guides carb oring to head I was lucky I had a crack in the spark plug hole so what i did took every thing down to the base & build it back up with factory parts thats how its done the the right way even a new clutch & stator
Please make use of the time honored punctuation we all learned in school. We would have less trouble reading your replies and comments.
Now read this slowly and remember I am normally very polite and will always try to show respect to all forum members no matter what the issue.....BUT
YOU ARE REALLY STARTING TO PI$$ ME OFF!!!

I don't care who you are, what you are or why you are but you don't join up to any forum and tell everyone they are wrong and only you have the answers to all situations that arise. Do you think we are all beginners with absolutely no common sense or experience? The combined knowledge of this forum is awesome and we trouble shoot problems of every kind without a major rebuild as the only solution. All parts and products need not have a Suzuki label on it to work properly and reliably.
Your idea of maintenance and repair is bordering on insanity and you might need some better meds as soon as possible. Oops, I may be wrong.........you already know what is best for your particular ailment.

[alantf]

Hey WW, have you noticed that mrgz250 has only been a member for 3 days, and all he's done is piss everyone off. I'm rapidly coming to the conclusion that he's just a troll, trying to cause arguments. Let's hope he vanishes up his own ars*hole in the near future.

[Water Warrior 2]

Hey WW, have you noticed that mrgz250 has only been a member for 3 days, and all he's done is piss everyone off. I'm rapidly coming to the conclusion that he's just a troll, trying to cause arguments. Let's hope he vanishes up his own ars*hole in the near future.
Yeah, I came back from vacation just in time to meet a new troll. He won't be here long thankfully.

[scully]

Hey these are great responses - I am wondering if they apply to my problem? Just picked up the bike and started riding a week ago and now I'm having idle issues. No smoke, the gas was pretty old but most of it has run through the carb already :\

I use the choke (full choke is super loud so I've been finding a "sweet spot". Bike will run ok when warmed up, but after 20 minutes of riding, the engine stalls when coming to a stop. Sometimes it stalls just sitting at a red light.

Should I just follow the advice on this thread already or could it be something else?

[BigBoss319]

Hey these are great responses - I am wondering if they apply to my problem? Just picked up the bike and started riding a week ago and now I'm having idle issues. No smoke, the gas was pretty old but most of it has run through the carb already :\

I use the choke (full choke is super loud so I've been finding a "sweet spot". Bike will run ok when warmed up, but after 20 minutes of riding, the engine stalls when coming to a stop. Sometimes it stalls just sitting at a red light.

Should I just follow the advice on this thread already or could it be something else?
Sounds like your bike is running too lean on fuel. Maybe from some kind of crud blocking it. Try B12 chem tool or Seafoam in your gas and install an inline filter to prevent it in the future. Here's the stuff you will need to install a filter.

https://goo.gl/12hdik
https://goo.gl/TMXtv4
https://goo.gl/8d865v
https://goo.gl/l6PQRQ

You may also want to clean your carburetor by removing it and getting personal. Even if none of this solves your problem it's good to do for your bike regardless as it's preventive/standard maintenance.

[wacio]

First make sure choke is turned all the way off. It may be causing mix too rich on warm bike.

There is idle adjustment screw on the right sire of the carb (plastic knob). I need to tinker with it (about half turn) depending how hot the bike is. This bike likes high idle (about 1400rpm). If adjusted too low it may stall when coming to a stop from cruising speed (engine little cooler).

My philosophy on the carbs in bikes that sat for a while is to try to run them for two or three tank fulls. Often the little varnish in the carb will eventually clear up. Prior to taking carbs apart, watch few videos on youtube made by Shane Conley about carb cleaning to avoid common mistakes. Parts for carbs are not cheap and easy to screw up. I bought mine in april and it runs much better now (after 400 miles). I still hesitate to take carb apart - my problem is very small leak causing carb to be little moist on the lower half. I bought rebuild kit that has all seals needed to rebuild and float needle valve (although opinions on the aftermarket kits and esp valve are mixed). Will eventually get it done if it doesnt stop by itself. Best luck.

[suzukix668]

I had the same problem cracked spark plug hole @ 58k & found that the head bolts were lose so I did a compleate top end tear down & clutch factory parts only now runs perfect 97k on her now