Front cam chain Guide removal

If it's broken or just needs tweaked

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mikexyz
Posts: 1
Joined: Wed Feb 08, 2017 5:15 pm

Front cam chain Guide removal

Postby mikexyz » Thu Feb 09, 2017 7:47 am

Hello,
I'm new to this forum but I'm in a process of renovating my 1982 nighthawk (CB650SC) and after a little advise.
It's not been used for 19 years till I bought it off an 80 year old guy who was giving up riding, unfortunately it's suffering from shrinking cylinder head seals + a blowing head gasket. I've stripped the top end but cannot remove the front cam chain guide - it is loose but there's not enough room to twist + remove as recommended by the Haynes manual, the guide's side wall are too big.
I do need to remove it as both the head + cylinder block surfaces have suffered from the blowing gasses, (almost looks sponge-like) + will need re-facing.

So, I'm wondering....
1. How to remove front guide?
2. How much metal can I take off before problems of valves meeting pistons occur?

Any advise gratefully received.

best regards, Mike

User avatar
tario
Posts: 166
Joined: Sat Mar 07, 2015 2:26 pm

Re: Front cam chain Guide removal

Postby tario » Thu Feb 09, 2017 2:33 pm

It sounds like you might need to shoot it with pb blaster or something similar. I know people make copper head gaskets for racing. They would add back some clearance. You can reuse them a few times too.
1979 cb650
1980 cb650

jeffjeff
Posts: 2
Joined: Mon Feb 13, 2017 1:31 pm

Re: Front cam chain Guide removal

Postby jeffjeff » Tue May 09, 2017 10:00 am

The cam chain guide seems stubborn but it will come off. You have to apply enough torque on it for it to turn and slide out.

Sorry to reply so late.. :-(


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