GS750 engine start, 16yrs

[stevetower01]

I am restoring a GS750 that has been stored for 16 years. It has oil in the crankcase and WD40 in the cylinders. Any suggestions on how to go about getting the engine ready to run again. I plan to do a compression test. Should I flush the crankcase? With what, kerosene? Engine has 42K mi. What should I not do?

[barnbiketom]

I usually do not flush it with anything but OIL. by flushing it, do you mean before starting? i'd at least drop the old oil and put in new. after you get it runing i'd changethe oil and filter AGAIN!!!
THEN:

also, depending on HOW it was stored and where.. I think i'd spray lube into each cylinder and turn the crank either with a wrench on the stator side, or by snicking it into 3rd gear and on the sidestand turn the rear wheel. that way the engine will turn over and not get hot . I usually do this on bikes i get that have sat. If theres any rust in the cylinder walls, that will help.

Barring a complete teardown and rebuild that's what I'd do first.


If you've already used the electric starter and it turns over, now you'll find that the fuel system is more than llikely messed up.
by that I mean is the tank spotless inside? does the petcock turn and the gas flow on the prime position? is the petcock filter clean? and finally but most importantly:

will the carbs deliver fuel to the bike on all four cylinders and let it run on idle, midrange, and wide open. I hope so but probably not!!!!
I rarely see a bike run properly that has sat or been 'stored' for any length of time, so each one is different. lots of times the #1 carb is plugged up totally and the others are not so bad. Why? the bike leans that way and that carb will, over time, get all the fuel if the petcock leaks!

that said, even if it starts up and runs PERFECTLY, then I'd check VALVE CLEARANCE no matter what . I've ruined a few GSs by riding them after getting them running only to burn a valve cause it was corroded from sitting.

hope this helps

[mrbill5491]

Restart

Well for one WD40 isn't a lube so it has evaporated a long time ago, I would squirt some light oil on top of the cylinders and rotate the engine a few times to help the rings out some, chances are they could have seized by now but one never knows. For sitting for that long, drain the oil and probably flush it with a #1 kerosene then maybe pull the oil pan off and clean when you can from it. You are gonna have to pull the carbs off and clean them for sure (resync the carbs) and check the valve adjustments to make sure none of the springs have collasped. Also check and clean the fuel tank, sitting empty that long it is sure to have rust in it, change the fuel lines too. When you get ready to fire it up, I would add a light oil 30w with a new oil filter (get a couple oil filters for this) and run the bike just enough till it heats up to operation temps then drain it, it should flush out any thing left in there, oh yeah have the bike on its center stand and run the the gears to clean them off as well too, then drain the oil and pour in your choice of lube and change the filter again. You'll have a bit of blue smoke from the residue oil on the pistons, it should clear out in few, though if the bike continues to smoke after you put in the other oil, then you have problems. As you can see this is a long process though a careful one, last thing you want to do is have new rings installed. Have fun!

[1_v8_merc]

If it was mine, I'd just put some diesel oil down each cylinder and fire that bitch up.

If it's gonna break, it's gonna do it then.

No special treatment. I wanna see it run in unfavorable conditions right away, just to give me an idea of how tough the motor is.

[stevetower01]

Thanks

Thank you all for the suggestions; I find them very helpful.

I do mean to flush, if at all, before starting.