GSX1100EF 1985 Compression Help!

[akronos]

this morning I decided to do a compression test on my new Gsx 1100 Ef. During the past few days I realized that the performances were not good. To my astonishment I found these values:


cylinder 1: 2.5 Bar
cylinder 2: 10.5 Bar
cylinder 3: 11 Bar
cylinder 4: 10.5 Bar


How is so much difference possible with cylinder 1? I think it's a valve problem what do you say?
Tomorrow i'll dismount the head and verify..

 

[fastbysuzuki]

Yes could well be a valve problem before you remove the head check the valve clearances.

 

[akronos]

Valve clearance are good on all cylinder. Between 0.7 and 0.12.
If i remove head i need a new gasket and bolt or only gasket? Do you think it could be a problem with elastic bands?

 

[fastbysuzuki]

Valve clearance are good on all cylinder. Between 0.7 and 0.12.
If i remove head i need a new gasket and bolt or only gasket? Do you think it could be a problem with elastic bands?

If you remove the head you will need a cylinder base gasket as well as a head gasket as you will break the seal on the base as for bolt and elastic bands not sure what you mean unless its cylinder head bolts and cylinder base orings if that's the case you likely will not need either.

 

[londonboards]

I would get the bike going and go for a spirited run for at least an hour, taking it up to maximum revs.

Come back and redo the compression test. Make sure you do it with with the throttle fully open, engine hot and the other plugs out.

You might just find that it has come good.

 

[akronos]

I decided to take everything apart. I'll do some pictures tomorrow. What head and base gasket do you recommend? In Italy I find very few ... only Athena gaskets. What do you think?

 

[londonboards]

Most people recommend that you only use genuine Suzuki gaskets.

You can always get gaskets from the UK Suzuki guys. They ship worldwide. Best bet is to call them or email:

https://www.robinsonsfoundry.co.uk/...4-1986.htm?vehicle_id=25#!gsx1100efecylinder1

 

[akronos]

I dismount the engine. Bore and piston are good. Rings perfect. What do you think?

 

[fastbysuzuki]

Given the no1 low compression reading you supplied there must be a problem with that cylinder was the rings free in the piston?

 

[akronos]

the piston rings are free, the seats clean. I inserted the rings into the cylinder and fit perfectly into the dimensions of the manual. (exactly 0.28m, in practice as new). The valves and valve seats, on the other hand, are very bad, even the o-rings at the base of the cylinders are damaged.