Stripped Exhaust Camshaft

[Guest]

When I pulled the valve cover on my GS550B to do a valve clearance check I discovered that the tacho drive skew gear on the exhaust camshaft was stripped and the corresponding piece of alloy had broken out of the valve cover which houses the tacho drive. I have purchased replacement parts for both. My problem is can anyone give me a quick run down on replacing the exhaust camshaft. How do I get enough slack in the cam chain. Do I replace the cam and sprocket or is it easier to slip the new cam through the existing sprocket and bolt it back up together.

Any ideas from you helpful people that have done this kind of thing before will be greatly appreciated. Obviously I dont want to disturb any more of the top end than I have to.

Cheers

Don

[Redman]

In your description you did not mention anything about the cam chain tensioner. The tensioner needs to be removed to get slack on cam chain. ANd then tensioner needs to be replaced and reset, which I dont fully understand, I just follow proceedure in the Clymers manaul.

Remove and replace the cam(s) along with the sprocket(s) attached to cam(s).

You will also need to know about how to align the cams with the ignition timing (crankshaft), which I do understand but still follow proceedure step-by-step in Clymers manual..

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[themess]

The Clymer manual should give detailed instructions with some grainy photos. Drop $25 on the manual. You'll also need Plastigauge, a torque wrench, and some gaskets.

[Nessism]

The Clymer manual should give detailed instructions with some grainy photos. Drop $25 on the manual. You'll also need Plastigauge, a torque wrench, and some gaskets.

No need for plastigauge.

Remove tank, spark plugs, engine cover over ignition points, rotate engine till No 1 piston is at TDC, remove valve cover, cam chain tensioner, remove camshaft bearing blocks, remove camshaft.

Timing new camshaft during install is a little tricky. Post back when you get ready for that part.[-o<

[Suzuki_Don]

No need for plastigauge.

Remove tank, spark plugs, engine cover over ignition points, rotate engine till No 1 piston is at TDC, remove valve cover, cam chain tensioner, remove camshaft bearing blocks, remove camshaft.

Timing new camshaft during install is a little tricky. Post back when you get ready for that part.[-o<

Nessism is that No. 1 piston at TDC on compression stroke.

[Nessism]

Nessism is that No. 1 piston at TDC on compression stroke.

Yes! (sorry I forgot that part).

Photo is not the most clear but you want the 1.4 T mark aligned on the crank.

#1 hash mark on exhaust cam parallel with the gasket surface

20 pins between the #2 and #3 mark on the intake cam.

Hope this helps.

[Steve]

... 20 pins between the #2 and #3 mark on the intake cam...

Be careful here, many people don't get the count right.

The pin over the #2 mark is counted as #1, the pin over the #3 mark is counted as #20, so there are only 18 pins between the marks.


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[Nessism]

BTW, repairmanualclub.com has the factory GS550 manual available for download. It's a big file so it will take a while to download but at least it's free.

[Suzuki_Don]

BTW, repairmanualclub.com has the factory GS550 manual available for download. It's a big file so it will take a while to download but at least it's free.

Yes I downloaded that one pretty soon after I bought the bike.

Thanks.

I gather that I have to remove the valve cover to verify that both inlet and exhaust valves are closed and that #1 cylinder is on compression. There is no other way to get #1 on compression without taking off the valve cover to observe the cam lobes is there.

[Suzuki_Don]

Be careful here, many people don't get the count right.

The pin over the #2 mark is counted as #1, the pin over the #3 mark is counted as #20, so there are only 18 pins between the marks.


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Thanks Steve for highlighting this to me, I would have had a sick running motor if I'd got that wrong.