GS674 won't start???

[Badooka]

Agreed. Too much alcohol will dry out even the best of us...

The liver is evil and deserves to be punished!

[ashdricky]

so I checked cam timing and tested the compression, the cams were off by 1 tooth on all four and this is what I got on the compression test...

TEST 3 (AFTER CAM ADJUSTMENT)

Cylinder 1 70-PSI
Cylinder 2 115-PSI
Cylinder 3 105-PSI
Cylinder 4 110-PSI

Terrible, and I also striped out the block at one of the small 6mm bolts at the very end of the head trying to torque it to spec....

[UK-GT]

so I checked cam timing and tested the compression, the cams were off by 1 tooth on all four and this is what I got on the compression test...

TEST 3 (AFTER CAM ADJUSTMENT)

Cylinder 1 70-PSI
Cylinder 2 115-PSI
Cylinder 3 105-PSI
Cylinder 4 110-PSI

Terrible, and I also striped out the block at one of the small 6mm bolts at the very end of the head trying to torque it to spec....

Did have the throttle fully open when you did the Compression test?

[megatwin]

after all the ether spraying,it wouldn't hurt to put a little oil in each cylinder,turn it over a few times,and re-check compression.
It seems all of them are low,a leak down test would be better than compression check at this point.

[tkent02]

If it hasn't run at all, it can't be expected to have perfect compression. Rings need to seat. At any rate compression is not the reason it isn't running, it's just not that low. It's actually within Suzuki's specs except for #1.

[ashdricky]

Did have the throttle fully open when you did the Compression test?

I actually remove the carbs completely for all tests.

after all the ether spraying,it wouldn't hurt to put a little oil in each cylinder,turn it over a few times,and re-check compression.
It seems all of them are low,a leak down test would be better than compression check at this point.

And also put oil in each cylinder which did increase compression slightly

If it hasn't run at all, it can't be expected to have perfect compression. Rings need to seat. At any rate compression is not the reason it isn't running, it's just not that low. It's actually within Suzuki's specs except for #1.

I havent tried to start it with the cams adjusted, I will take this time to put the 550 sprockets on the 650 cams and use those as I used the original 650 tappets. is the only way to adjust the tappets to replace the shims?

[tom203]

".....is the only way to adjust the tappets to replace the shims? "

Does this mean you have not checked clearances yet?

[ashdricky]

".....is the only way to adjust the tappets to replace the shims? "

Does this mean you have not checked clearances yet?

yes I have not, I was told, that the 650 ran prior to me getting it, and made the amateur mistake of just putting the top end back together after lapping the valves.

[ashdricky]

".....is the only way to adjust the tappets to replace the shims? "

Does this mean you have not checked clearances yet?

wow..... I just read the service manual regarding shim adjustment..... amazing how a small amount of research can save me embarrassment.

[cowboyup3371]

Might I suggest this would be a good time to contact Steve for his valve adjustment spreadsheet. It will help you with the procedure.

[ashdricky]

Using a 0.0015 in feeler gauge I was able to get it between the cam and bucket on 1 out of eight valves, on all the others there was no clearance at all, so I am guessing that since the lobes are still in contact with the shims that the valves may be open ever so slightly?

[tkent02]

That's the usual case if they are never adjusted. Next comes burnt valves, and usually a trip to the shed to sit for twenty years or so.

My trick for this, is to put the cam in the position to check a pair of valves. See if the shim will spin easily in the bucket, or is it stuck? If it spins, it's got at least a tiny bit of clearance, go one shim size smaller. This should put you around .05 - .08 or so. If it's stuck, it's got zero or negative clearance, going two sizes smaller should put you somewhere under .10mm, which is OK.

You may have some even worse, where two sizes smaller is still not enough, but in most cases this will get you in the ballpark.

[JayWB]

I actually remove the carbs completely for all tests.


And also put oil in each cylinder which did increase compression slightly

If your compression problem was with the rings your compression would have risen a lot more than slightly with the oil in the cylinders.

Check it again after getting the valve lash right. You should get much better numbers then. If not, you've burned some valves.

[ashdricky]

ok so since my last post, I ordered the appropriate shims as well as took the cams out and timed it from scratch, took many kicks but it did ROAR to life. so now I have a new issue, SEVERE oil loss...


I did notice oil in plentiful supply appearing around these two stud bolts,



However by far the majority of the oil was coming from underneath the sprocket cover, after removing the cover it was not entirely clear where the source was, it appeared to be from this hole in the case.

[Nessism]

Did you install the copper washers under the outer four head nuts?

Photo of that hole in the case has my head spinning. What angle did you take that photo at. Looking up at the bottom of the engine?