oil in carbs?

[newbie851519]

i have a 1980 gs850gt
i'm pretty new to this whole thing, have some popping problems when i'm decelerating or maintaining speed, so i've taken the bike apart to try and fix it up.
1) found that there was no gasket from one of the exausts to the cylinder - might that cause the popping? i've ordered 4 new ones
2) there is oil leaking from the boot where carb #1 (farthest left when sitting on bike) meets the air cleaner housing. is this normal? there is also a small puddle of oil in the bottom of the air cleaner housing, also normal?
3)the carbs all look really clean, i think they were cleaned not too long a go (i just bought the bike)
4) the exhaust pipes are all black inside, except one which is white (#3 from left) - what does this mean?
5) the breather hose from the crankcase to the air cleaner has some gummed up oil in it (not much, but its definitely there) - is this a problem? also it smells slightly of gas - is this bad?

any help would be much appreciated - i've consulted the shop manual but haven't found many answers...
thanks!
-nick

 

[chiphead]

In my opinion:
1)yes
2)Not normal. Oil is being forced through the breather on top of the valve cover back into the airbox. Is your oil overfilled? I seem to remember cam timing being off can cause this too but I'm not sure about that one.
3)Clean inside or just looks clean and purdy on the outside?
4)#3 is running lean.
5)yes.

 

[fgh]

What chiphead said. Oil in the carbs is a crankcase ventilation problem. I don't know how your bike is supposed to be set up. On mine there is a 1.5" by 2.5" cover bolted on top of the valve cover. There is a hose from the cover to the air box. There is also a drain on the air box. The drain looks like its pinched shut, but there is a small opening. It would be wise to get your vent/intake system back to stock set up and make sure its clean, no plugged passages. That should take care of the oil in the carbs problem. Clean your plugs and go for a trip, if performance seems normal. Check your plugs when you get back. If they aren't all the same let us know.

 

[sissonk]

I remember reading on this site of the trouble a petcock that doesn't seal properly causes .Gas slowly floods into the carbs and back into the air box , it evaporates leaving behind a substance that could be mistaken for oil . this happened on my bike and at first I thought it was oil . if that is the case that would explain the black pipes , running rich and the popping could be #3 running lean. to check its seal just pull off the gas line and if fuel is coming out well that is one problem , make sure the petcock is in the on or res postion .

 

[newbie851519]

2)Not normal. Oil is being forced through the breather on top of the valve cover back into the airbox. Is your oil overfilled? I seem to remember cam timing being off can cause this too but I'm not sure about that one.
3)Clean inside or just looks clean and purdy on the outside?

No, I don't think the oil is overfilled. I run it for about 5 min, let it sit for 5 min to drain the oil back, and then fill it to the top line in the sight window, right?

Clean inside. I'm pretty sure this was done a year or so back.

Thanks for the advice, I'll get back to you all with results...

 

[newbie851519]

need more help

need more help

I remember reading on this site of the trouble a petcock that doesn't seal properly causes .Gas slowly floods into the carbs and back into the air box , it evaporates leaving behind a substance that could be mistaken for oil . this happened on my bike and at first I thought it was oil . if that is the case that would explain the black pipes , running rich and the popping could be #3 running lean. to check its seal just pull off the gas line and if fuel is coming out well that is one problem , make sure the petcock is in the on or res postion .

The petcock doesn't leak.

I did put the petcock switch on the "pri" position, thinking it was the "off" position for about 2 weeks every time i parked the bike...could this have caused the backup of gas?

How do I adjust #3 to run richer?

Do I need to re-synch the carbs after taking the whole unit off the bike, even if i didn't open them up at all? should i re-synch anyway? if so, how cheap can i get a carb synch kit, and where is best? LAPS?

Thanks for the help!

 

[fgh]

The petcock doesn't leak.

I did put the petcock switch on the "pri" position, thinking it was the "off" position for about 2 weeks every time i parked the bike...could this have caused the backup of gas?

How do I adjust #3 to run richer?

Do I need to re-synch the carbs after taking the whole unit off the bike, even if i didn't open them up at all? should i re-synch anyway? if so, how cheap can i get a carb synch kit, and where is best? LAPS?

Thanks for the help!

Yes, Leaving the bike on "pri" for a coupla' weeks could greatly contribute to the gas problem. In a perfect world the floats should close the valves and keep the gas out. But the world ain't perfect so Suzuki did the right thing and built the vacuum actuated petcock. Leave it in the "on" or "res" position and it won't overflow, as long as the petcock is OK. To check it put it in "on" or "res" and remove the fuel line from the petcock. Put a piece of hose on the petcock and put the other end in a gasoline tolerable container. No gas should appear in the container. Give it an hour or so. If gas appears rebuild or replace the percock.

As far as I know the only lean/rich adjustment on most stock carbs is the idle mixture screw. And as the name indicates it only impacts the mixture at idle. They don't have enough capacity to enrichen the mixture at speed. That is done by the slides in the carbs. Pull the cover off the top on the #3 carb and check to see that the springs OK and that theres nothing in there that would prevent the slide from rising. The slide should pull out without any resistance. It must move freely. You might have something plugging the jet and could try a gentle shot of air or carb cleaner to clean it out. With some mods, on some carbs the needle will be raised by putting a washer under the needle head before its inserted back into the piston. I would probably pull another and compare the two to make sure they are set up the same.

Now I really don't know if the slides will come out with the carbs on the bike. You'll have to try and see what you can do. It could of course be other stuff. A stuck float, a stuck needle valve, a blocked passage or something else I don't know about. I've always been able to keep my carbs in order by making sure they are clean, all parts install as intended and operate as intended. LOL

 

[t3rmin]

This thread reminded me that I forgot to re-attach the crankcase breather hose when I re-mounted my carbs yesterday. Thanks, and good luck with your issues! ;-)

 

[jeddininja]

Trying to get #3 to run richer may not be required (and would take a rejet for anything above idle). Which exhaust manifold was missing the gasket? If it was the same cylinder, there's your problem. An exhaust leak translates into less back pressure. less backpressure means more airflow. More airflow (without a corresponding increase in fuel) means a lean mixture.
If it was a different cylinder, I'd check the boots that connect the carb to the cylinder head (look for cracks or tears). If you can get 'er started, spray a bit of wd40 in the area where the carbs connect to the head. If the idle changes, you've got a leak, which will also cause a lean condition.

btw, are you sure the gasket was missing? I'm assuming you mean the copper crush gaskets. Sometimes they're hard to see stuck in the head. If you've already got one stuck in there, and you put in another one, you'll have a leak for sure.

 

[newbie851519]

btw, are you sure the gasket was missing? I'm assuming you mean the copper crush gaskets.

yea, the gasket was missing, for sure. the white lined exhaust was on a different cylinder than the missing copper crush gasket.

i've been replacing the spark plugs, and just found out that the plug on #3 (the one with the white lined exhaust) is REALLY hard to get out. i've been working it with wd40, no luck so far. am thinking maybe the plug has been in there so long, maybe it isn't firing...that would explain the white exhaust and maybe the popping too... right?

this still doesn't explain the oil in carb #1, though...that's still a mystery.
any advice for getting that pug out?
thanks...

 

[jeddininja]

usually, white means lean (white and ashey). this is because the perfect fuel/air ratio burns very hot. Running an engine this way will burn it up pretty quickly. The 'proper' fuel/air ratio has a little extra fuel that evaporates, taking heat with it and helping to cool the engine. If the carb is really running lean, I'd suspect a clog somewhere or an air leak. If the bike was running fine at some point in time, the jetting probably would not change, unless the jets worked loose and fell out (ask me how i know) . At any rate, i'd go through the carbs again.
when you had the pipes off, were they white all the way up to the head? did the outside of the pipe have a blue tint (excessive heat turns chrome blue)? If it was not firing, you would get a wet pipe and probably lots of carbon build up.
I would soak the plug a few times a day with liquid wrench ( i think people recommend pb blaster around here, but i've never tried it). do this for a few days and try it again.

 

[newbie851519]

updates.

updates.

well, I don't think I have the ambition quite yet to pull apart the carbs and completely rebuild and clean them. if it was the breather system being clogged (did I understand it right that that might have caused it??) then that is all cleaned up with a new breather hose and the chamber from the breather hose in the air filter housing, which was completely clogged is now free and open. so it should be fine.

The plug on #3 I finally got to come out, and it looked fine to me, a brown look with no goo, black oily stuff, or white pimples, and no buildup of any kind. maybe the crush gasket was on the same one, I can't seem to remember now...Any how, I'm thinking of running some carb cleaner additive in the gas through the system to see if it helps at all.

Do you all think that could help at all??

The petcock doesn't leak, so that's not the problem...

I've ordered a carb synchro kit, so that might help performance, too...

Thanks for the advice, once I get the bike back up and running completely I'll let you all know if there are still problems.

-Nick

 

[GregM.]

Hey Nick... I see you're working away at it.
I didn't realize, when I sent you that long email a few days ago about checking your intake boots, that you had a couple other threads going. The only one I'd seen was the airbox one. So anyway, I see you got lots of good advice, and those boots were brought up. Sounds like they're Ok... so, that's good. Someone mentioned a good test - to spray carb cleaner on 'em to see if idle changes... This showed a leak in mine.

And now that I've read more about your oil leaking between #1 carb and airbox situation... Well I don't know the answer. But I have the SAME thing, so let me know when you figure it out. :-D
Are you always parking the bike on the sidestand? One thing someone here suggested to me was, park it on the centerstand. Then everything doesn't go down to carb #1. That's how I park mine most the time now. Still have the oil issue though, but it seems to have spread out the mess over a more balanced area.:shock: :? :-D

 

[newbie851519]

Greg,
Yea, of course I will let you know what happens with the oil thing. I always park it on the sidestand...I'll do the boot test soon, just to make sure, but i think they're fine.
And let me know if you figure out the oil thing, too.
-Nick