Replacing valve seals, which one?

[Maddevill]

And...

.. along with the valve seals I heartily recommend at least lapping all the valves in. Will help restore any valve sealing issues. I also agree with the guys who said it could be rings. I would definitely look into that as well.

[overboostin]

Thanks for all the suggestions guys. I'll see what I can do to clear it up.

[Steve]

I think an Italian tune-up will take care of it.

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[Agemax]

I think an Italian tune-up will take care of it.

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thats pretty cool............

[hikermikem]

Thanks for all the suggestions guys. I'll see what I can do to clear it up.

Well, if you do decide to pull the head, valve stem seals, and valve cover gasket & half-moons from Z1 are much cheaper than OEM and just as good. Use only a Suzuki head gasket though, the after-market ones don't get a lot of good press here...

[chuck hahn]

Just to expound on the Italian Tune Up a bit.


Ever notice that on an engine with a blown head gasket and coolant gets to a cylinder that the cylinder is as clean as the day the engine was made?


Heres why...the coolant instantly crystalises the carbon and its expelled out the exhaust. Its much like if you fry a burger in the skillet and theres the crunchy stuff left behind and you dump water in the hot skillet...the crusty stuff releases rather quickly and you can easily clean the skillet.

So heres what you do to "de-coke" the bikes cylinders. Pull the airbox so you can get directly to the crabs and start the bike with a fan blowing on the engine. Let it warm up real good..say 10 minutes or so that the cylinders are good and hot inside.

Next take a squirt bottle and fill it with cold water. Run the RPMs up to 6 or 7 grand and start squirting the water into the carbs...keep on the throttle and keep the bike running. Squirt the water just to the point that the bike will almost stall,,, but not stall. Do this on each cylinder 4 or 5 times and youll have an engine that is spotless inside the cylinders and the tops of the pistons. It will even knock carbon deposits off the valves.

[mrbill5491]

Back in the day, if a car/truck had a lot of carbon build up on the pistons, we would set it up on a high idle and slowly pour transmission fluid down the carbs and let it smoke like the devil. Then we would take it out and run it hard for a few miles, seemed to work.

[hikermikem]

So heres what you do to "de-coke" the bikes cylinders. Pull the airbox so you can get directly to the carbs and start the bike with a fan blowing on the engine. Let it warm up real good..say 10 minutes or so that the cylinders are good and hot inside.

Next take a squirt bottle and fill it with cold water. Run the RPMs up to 6 or 7 grand and start squirting the water into the carbs...keep on the throttle and keep the bike running.

Seems I've read on here a slightly different technique - instead of removing the airbox to get access to the engine's intake, remove the sync screw from each cylinder intake port & inject water at that point using an eye-dropper or similar...

I don't like messing with airbox removals myself - too many tools get tossed .

[chuck hahn]

I like to be able to mist the water into the carb intakes...and wouldnt removing the sync screws cause a heck of a vacuum leak and make keeping the engine running harder...and youll need all 4 open at the same time, so I cant see the practicality of doing it that way.

Many bikes you can get to the throats without totally removing the airbox..such as the 750s. And you can access the intakes thru the airbox on the 1000s by removing the upper half and squirting into each hole from the back.

Also on the 1000s, you have to remove the carbs before you can remove the airbox.
My 750 airbox is off in a matter of a few minutes..and no removing the carbs first.

[tom203]

Yeah that's what I figured would be best. It's a shame because the engine only has 14k on it. I think it was just sitting for awhile.

Since it's left hand pipe smoke, make sure you rule out the possibility of petcock dribbling gas into #2 before you go tearing into an engine at 14k. Personally, I'd run it some more and offer sacrifices. Find out if oil is disappearing.

[1948man]

I think an Italian tune-up will take care of it.

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Ferarri, huh? I always figured that phrase came from a bunch of Italian guys in Jersey getting rowdy. Didn't know it was so "sophisticated."

[1_v8_merc]

A lot of these bikes smoke when they come out of storage. It could be running rich, or carbon build up in the cylinders or exhaust.

If the bike rides and pulls strong....just ride it. It's not going to explode.

[Weeksz]

Valve seals will smoke at startup and when you close the throttle when riding.
If it smokes on accel most likely it's rings.

This. I've got the same problem, 81 GS750. Smokes out of left 2 to 1 pipe on start-up. Usually (blue)smokes when revved, not really sure about when I close the throttle(its been a while and I dont ride behind me much) and burns oil. Goes away after a while of riding. I'm looking to get work done soon or attempt it myself and would like to buy the bits to fix it.

I laid down the bike this past fall so a compression test would require me to re-assemble and fill with oil to fire. can you do a compression test without turning over the starter?

Edit: So by re assemble I've got my carbs off and stator cover removed.

[Steve]

I laid down the bike this past fall so a compression test would require me to re-assemble and fill with oil to fire. can you do a compression test without turning over the starter?

Edit: So by re assemble I've got my carbs off and stator cover removed.

If you have a kick starter and a strong leg, you could do it without using the starter.

If all you have off is the carbs and the stator cover (which means there is probably no oil in it) put a 2x4 under the left foot of the centerstand, put in at least 3 quarts of oil, then go ahead and use the electric starter. Not having carbs on is actually a PLUS, as there is NO restriction. You are supposed to hold the throttle wide open, anyway.

By the way, where do you live that you managed to get an '89 GS750?

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[Weeksz]

If you have a kick starter and a strong leg, you could do it without using the starter.

If all you have off is the carbs and the stator cover (which means there is probably no oil in it) put a 2x4 under the left foot of the centerstand, put in at least 3 quarts of oil, then go ahead and use the electric starter. Not having carbs on is actually a PLUS, as there is NO restriction. You are supposed to hold the throttle wide open, anyway.

By the way, where do you live that you managed to get an '89 GS750?

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ok thanks. well I've got no centerstand. and i was just kidding its an 81..