Exhaust sparks & smoke

[gtzuki750]

working on a 77' gs 750 for a while now.. the bike currently doesn't have the mufflers on ,neither air filters (for the sake of constantly taking stuff on and off) . FIRST: yesterday i started the bike (with a little starter fluid) started it up in intervals , meaning let it start up and run for a little while and shut it off did this 3 times third time smoke started coming out of the carburetor #2 (engine off and WHITE smoke) I don't know if its some kind of oil thing or what, issue ? or just paranoid? SECOND: when I started the bike today same process, started the bike up with a little starter fluid got her running choke all the way up , bike started getting super hot "Obviously" ya I know.. a handful of sparks came out of the pipes and then the bike died and something just didn't feel right , now I didn't start the bike up after this because I was kinda scared that something may be going on between these sparks and the smoke. whether its piston/engine related or if im just being really paranoid. so ive come to hear from the experts before I make any rash decisions like yanking out the engine.

sincerely your average paranoid forum noob
-Gabe

[almarconi]

Clean your carbs, install some mufflers and an aircleaner, you should be good to go.

[hjfisk]

It kind of sounds like you are running it way lean and are burning all the carbon deposits off everything inside, next is the motor melt down . STOP with the starter fluid, install some air cleaners, and an exhaust, clean your carbs PROPERLY, and check out the read first Newbie mistakes, this should help you save your bike.

[Brendan W]

I agree with the others. I'm not going to get on your case about running without cleaners and mufflers because I had to do it as well - just to see, a long time ago with a Z.
I would not be too worried about white smoke wandering back after shutdown. Sooner or later the crank stops at an inlet opening at the end of a power stroke on some cylinder.
Sparks probably happen more often than we realise - that's what mufflers are for.
What did you mean by ' super hot '. Air cooled motors don't like extended idling especially indoors with ambients over 70F (?). Most would recommend a fan even for something like a carb balancing session. On top of this you used rocket fuel and derestricted the airflow , leaned out the mixture which will be slow burning,meaning the fire is not out when it hits the exhaust valves and headers so it runs hot.
It's hard to imagine you managed to burn a valve or melt a piston with little or no load on the motor for shortish runs.
With my optimistic hat on I would say you need to check compression and valve clearances just as you would for a first start after a rebuild and normal fuel and all the cleaners and mufflers fitted.

[gtzuki750]

Alright, so correct me if theres anything im missing anything but this is what im gonna do since ive already cleaned the carbs thoroughly. 1.valve adjustment / compression 2. put stock exhaust and filters (I bought the bike with pod filters, so those will have to do) and go from there. Also I didn't care to think about this but I did put about half a bottle of sea foam in the tank so that is probably playing a role in the sparking. and I should be alright with figuring out the fuel mixture. But does that sound about right ? & ill check out the newbie page.

[eil]

Alright, so correct me if theres anything im missing anything but this is what im gonna do since ive already cleaned the carbs thoroughly. 1.valve adjustment / compression 2. put stock exhaust and filters (I bought the bike with pod filters, so those will have to do) and go from there. Also I didn't care to think about this but I did put about half a bottle of sea foam in the tank so that is probably playing a role in the sparking. and I should be alright with figuring out the fuel mixture. But does that sound about right ? & ill check out the newbie page.

If you've cleaned your carbs (the proper GS Resources way), the seaform will do nothing aside from make your exhaust white. (And I maintain that it does nothing in any event, but some claim otherwise and I'm not trying to start an argument about it here.)

If you're running pods, you more than likely have a long road of carb tuning ahead of you to get the bike to run right.

Don't use starting fluid, it can cause damage to the engine and the fact that you have to use it to start the engine says something else is seriously wrong.

Most of all, read your butt off and get caught up on all of the bike's regular maintenance before trying to troubleshoot anything. Good luck!

[Brendan W]

Alright, so correct me if theres anything im missing anything but this is what im gonna do since ive already cleaned the carbs thoroughly. 1.valve adjustment / compression 2. put stock exhaust and filters (I bought the bike with pod filters, so those will have to do) and go from there. Also I didn't care to think about this but I did put about half a bottle of sea foam in the tank so that is probably playing a role in the sparking. and I should be alright with figuring out the fuel mixture. But does that sound about right ? & ill check out the newbie page.

Go for it. Life is short. Double check the fuel hasn't been priming away filling the cylinders.