Oil leaking from exhaust port...

[Guest]

so im sure that title will draw a few in, let me explain. and ill cut straight to the chase and then some backround info

bought an 81 gs650g for cheap knowing it would need work but was able to be riden. 40k on it all hard miles from what it seems.

the exhaust bolts decided they wanted no more to do with this engine over time and like 3 or 4 are missing bought it like this and have yet to helicoil them so the exhaust ports on the outer cylinders dont seal completely.
well ive riden it like this for about 1200 just seeing what it's going to need and what direction i wanted to go with it...

now the last time i rode i got home and noticed my right boot was nice and shiny, it looks like the oil is coming from the exhaust port, and it's not a slow drip really....

any ideas?

(really hoping it's not the ring(s) but it seems like it might be)


P.S.

so i got the bike from a previous coworker and he told me it was a bit beaten but at the price i couldnt really pass it up.
i know it needs exhaust header stud kit/clutch springs if not whole kit/soon tires/could use a rewiring
otherwise its been a fine bike so far
so i guess for giggles does anyone know how much it normally costs to fully rebuild one of these motors?
or how much on avg a decent motor all done can be? im trying to decide if it's worth doing or trying to sell and try to find a larger GS (though i did fall in love with this specific bike, love it's proportions and styling)

[Nessism]

Most likely a valve cover or tach gear leak. How long since the last valve adjustment?

[boredinmemind]

Great question, not in the 1200 miles ive owned it.

i was thinking valve cover also, and it's leaky on the opposite side of the motor but looking at it theres no way it would cross over and get on my right boot only, and left boot side is clean except the old sludge.

but actually to support the valve adjustment idea, i did alot of cold riding with this bike, like almost always below 60f, i mean i rode on xmas day (in central NY) running 10w40 now this oil leaking only really poped up in the last couple weeks where it's been into the 70's and 80's so oil getting thinner slipping past because out of adjustment? sound like it could be it?
if so, would putting 20w50 in should theoretically slow it down, maybe confirming and allowing me to ride it to my mechanics house?

also i apologize, im not well versed on GS's the tach gear i assume you mean where the tach cable goes into the motor? (ill check that) (EDIT: i checked where it goes into the motor casing and it's totally clean)

[Nessism]

Clean the engine and find the leak source, then fix it. At the same time, do some maintainance. Valves must be maintained or the engine will fail.

[tom203]

If you're willing, get a cam cover gasket, check/ adjust valve clearances and you might find the leak disappear. Otherwise dump it and move on. Rebuilding this motor is expensive- you'd be better off finding another bike.

The 81 gs650 used a different cover gasket than the later 82 and 83 years, so beware. The cover bolts are held on with about 8 ft-lbs of torque - overtightening creates problems.

[geol]

The comment aboui the exhaust bolts being missing... not really familiar with your bike but almost all bikes use M6 or M8 studs to retain the exhaust flange clamps. I would guess your smaller bike uses M6. When you try to remove the nuts from the studs, the nuts will often be galled onto the studs and the studs will turn out. If there is empty thread, consider that the hole contained a stud.

As far as your leaky carb holder, first cylinders are numbered 1 to 4, left to right as you sit on the bike. If the #4 carb holder has oil on the outside, it came from either the valve cover gasket leaking or less likely, the intake cam plug on that side. The cam chain tensioner can leak but it likely will just mess up the block and top of the engine behind the block.

It is time for you to adjust valve clearances anyway... get a new valve cover gasket and have at it... pretty sure that will end the oil leak. As I looked at the title of your post, it said exhaust port but the carb holder is on the intake side... just a little confused.

[tkent02]

If you're willing, get a cam cover gasket, check/ adjust valve clearances and you might find the leak disappear. Otherwise dump it and move on. Rebuilding this motor is expensive- you'd be better off finding another bike.

The 81 gs650 used a different cover gasket than the later 82 and 83 years, so beware. The cover bolts are held on with about 8 ft-lbs of torque - overtightening creates problems.

8 ft lbs. = 96 inch lbs, way too tight.

[geol]

All the Suzuki factory service manuals I have seen note four types of M6 bolts. Two are the "not marked" and the "4" on the head. These have a torque value of 3 to 5 ft/lbs. The other two types of bolts have a Suzuki "S" on them or a "7" and the torque value of 5 to 7 ft lbs. That makes 84 in/lbs the highest M6 torque value for these engines or even the frame, etc. I can't recall what type bolts are on the cam cover but I am pretty sure they are not the latter type, if memory serves. I replaced all mine with socket head stainless bolts.

[boredinmemind]

hey guys, sorry for the gap there.

after talking with some people i do believe it's in the head.

but i'd like to explain a bit more.(also ill be taking some pictures shortly)

idk when they switched to studs, but all of mine are grade 8 bolts, if PO did that or it was like that previously idk.

for the sake of ease, lets consider looking at the motor from the front of the bike so your looking at the exhuast, from left to right, cylinder 1,2,3,4.


so picture there being no bolts in cylinder 1's exhaust flange, it is held there by the exhausts rigidity only, so naturally oil would seep out over time, what im talking about is oil coming down past the valves for some reason on this cylinder more,
so i guess the question is, is there any guide for the head rebuild? i'd like to try to narrow down a list of parts to see what it might cost, or if anyone would have a quick basic list of what i would need for a head refresh i'd be grateful.

[Nessism]

Purchase bike, perform no maintenance, ride 1200 miles until it starts puking out oil. Now instead of performing some maintenance and looking for the source of the leak (and replacing missing bolts), you want us to estimate the cost and provide rebuild info?

[cowboyup3371]

for the sake of ease, lets consider looking at the motor from the front of the bike so your looking at the exhuast, from left to right, cylinder 1,2,3,4.
.

You actually have this backwards; if you are looking at the engine from the front of the bike, #4 is on the left (throttle hand) and #1 is on the right (clutch). Two is next to 1 and 3 is next to 4.