smoke from valve cover breather tube

[Elkon]

Hello folks,

I will preface this by stating that I have limited mechanical knowledge but do pick up on things fast (its a matter of knowing what to research). my '80 gs850 is having a few issues:

The carbs sputter when cold and sometimes when running very little throttle. PO bought bike from "friend" who rebuilt the carbs a year or 3 ago. The boots are nice (although some rtv appears to have been used on carb 1 where it attaches to the boot.(Need to be torn down and cleaned per Bike Cliff's site but they may be contributing to the issue). I will be taking care of this as time and finances allow (1st baby incoming in about 5 weeks).

There is a set of el'cheapo pod filters on it that sometimes will have some fuel in them (appears to puff out when carb sputters)

After some riding (15-20 min) the breather tube from the valve cover will start to show smoke coming from it. The smoke is not thick but is noticeable. The moment I turn the bike off the smoke stops.

The valve cover may be painted (i read in another post via the search option that this may be causing some local heat buildup causing the smoking) The pic is of the cover. The bare area is after some mild scraping with a roofing nail. I had the bike out on Memorial day and that is when I first noticed the smoking. I also saw what appears to be a bubbling of the paint on the cover (visible in pic).

There may be some (minimal) fuel somehow in the valve area (no idea here). I could be very wrong on this and am waiting a second opinion. Will update when able.

I had the shims checked and all is within tolerance.
I checked the compression (starting with cylinder 1): 123 130 129 130. From what I read this should be good.

Any thoughts are appreciated. (i did utilize the search function but had minimal results...most likely a fail on my end. )

[Ghostgs1]

Hello folks,

I will preface this by stating that I have limited mechanical knowledge but do pick up on things fast (its a matter of knowing what to research). my '80 gs850 is having a few issues:

The carbs sputter when cold and sometimes when running very little throttle. PO bought bike from "friend" who rebuilt the carbs a year or 3 ago. The boots are nice (although some rtv appears to have been used on carb 1 where it attaches to the boot.(Need to be torn down and cleaned per Bike Cliff's site but they may be contributing to the issue). I will be taking care of this as time and finances allow (1st baby incoming in about 5 weeks).

There is a set of el'cheapo pod filters on it that sometimes will have some fuel in them (appears to puff out when carb sputters)

After some riding (15-20 min) the breather tube from the valve cover will start to show smoke coming from it. The smoke is not thick but is noticeable. The moment I turn the bike off the smoke stops.

The valve cover may be painted (i read in another post via the search option that this may be causing some local heat buildup causing the smoking) The pic is of the cover. The bare area is after some mild scraping with a roofing nail. I had the bike out on Memorial day and that is when I first noticed the smoking. I also saw what appears to be a bubbling of the paint on the cover (visible in pic).

There may be some (minimal) fuel somehow in the valve area (no idea here). I could be very wrong on this and am waiting a second opinion. Will update when able.

I had the shims checked and all is within tolerance.
I checked the compression (starting with cylinder 1): 123 130 129 130. From what I read this should be good.

Any thoughts are appreciated. (i did utilize the search function but had minimal results...most likely a fail on my end. )

Hi Elkon, Welcome to the GSR. Looks like you might want to check the carbs carefully to be sure they are clean and assembled correctly, jetting etc. I doubt that you have enough paint on the valve cover to cause any smoking issues. Probably a bit of blow by and that is to be expected on these older bikes, your compression says it's in descent shape so not to worry. Good luck with the bike. Best Regards, Ray

[Big T]

As you've realized, the carbs need a good cleaning and adjustment

Sounds like you'll have to be scraping RTV off everything

As for the valve cover, some smoke should come out of the top of it. Most people hook up a hose and a filter to the connector on top and vent it back behind the carbs

As for the paint peeling, it's really hard to tell what's going on there. Could just be a crappy paint job coming off, I doubt your motor has gotten so hot that the paint is bubbling off

[Elkon]

Thanks for the insight folks. On the Memorial day ride i did a sizzle test (outside temp was high 90s) after about 60 miles at 40-70mph. sprinkled some water on the intake side and it kind of popped and rolled (semi violently) on the fin as it boiled away.

As far as the carbs go...what would you think an estimated cost would be to take care of them? (from what I can tell I need to purchase all new rubber bits and possibly jets(the jets calc. is beyond me though as the exhaust is not stock...now 4-2 and has mufflers from an 80-81 virago on..))?

On the same note, what would a time frame be for it? is it possible to do in a 3 day weekend / have heard nothing but warnings about how bad it is to work on carbs and that there is no way i can improve it..only mess it up worse...



( I know i derailed my own thread a bit and apologize)

[Ghostgs1]

Should be able to reuse bowl gaskets, if you are carefull. New orings from Robert Barr - cycle orings less than $20, carb cleaner and elbow grease. Ray

[Big T]

Cost - about $50 for O rings, carb dip and carb spray

Lots of people do them during the week as a 24 hour dipping per carb body is recommended

You will need an impact driver, but that's something that will be useful for other repairs

No new jets required

Plenty of info available here on how/what to do

[BassCliff]

Hi,

The carbs need to be properly cleaned. You can do it yourself cheaply as has been described and documented. If you absolutely don't want to do them yoursef, send them to one of the GSR members who advertise in the Services section.

Have you adjusted your valves? Or did you pay a shop to do it?

If you don't want to see the smoke coming out of the bare naked breather, then put a filter on a breather hose, something like this:



Pictured above is a UNI product. They are available all over the place.

"Fuel in the valve area"? What does that mean?

If there's fuel in the oil then you'll have to change the oil and find out why your carbs or petcock are leaking.

If there has been RTV used on the carb intake boots then they are not "nice". I would suspect they are leaking. That's why there's RTV on them. You won't regret installing new intake boots and intake boot O-rings, also available from http://cycleorings.com.

After the carb cleaning, valve adjustments, intake repairs, you'll have to vacuum sync the carbs and set the idle mixture screws. But don't worry, it's all well documented on my website and in the forums using the search function.

Here's what NOT to do: Top 10 Newbie Mistakes


Thank you for your indulgence,

BassCliff

[Suzuki mad]

OK, I'm not a GS850 expert but as with all GS's the removal of the standard airbox and fitting of pods has an effect on GS's that will cause popping or running problems. Few people have the time and effort to sort out the jetting correctly when the change the airbox's.

The smoke's been covered by basscliff (there should have been a pipe that went back into the airbox and you wouldn't have seen it in standard trim.

I wouldn't be bothered by the paint on the cover unless its too unsightly for you. As for compression there's nothing in it to say that its a poor motor.