cb750 exhaust gides

[williamc89]

ok everyone i hope tango can help me out on this but i want to hear if anyone else has heard of this,

my coworker is rebuilding a 78 cb750 ss and the bike only has 9,000 on it and the exhaust gides were lose,[they had play] he said alot of people has told him that it is a comon problem on the 750s but i havent heard or seen anything about that on the sohc forum,


is it true or people just pulling his chain,

[cb500bobber]

Why don't you see if he would join the forum so he can post pics

[williamc89]

i ve been tryin to get him to but he says he doesnt have time to ,

[cb500bobber]

Well atleast give him the invite to our hang out spots

[tango911]

exhaust guides? id have to see what he is talking about. Theres the pipe, the clamp, and the Flange and the exhaust gaskets. you insert the gaskets, then connect the flangs to the engine, then connect the exhaust to the flange. so not sure what he's talking about.

steve

[felkman]

I am guessing he means valve guides!

[cb500bobber]

What are exhaust gides and I am pretty sure tango you're on the right path

[gr1976]

I'd guess valve guides as well. I had to replace them on my '74. If they are loose just get them replaced. AAA cycles did mine.

[williamc89]

ya sorry the exhaust valve guides,,,

i told him were we go on friday night and what night the sterr inn is,

[tango911]

u guessed it felkman. Honda $16 each on westernhonda.com the intake and the exhaust are different part number fyi. I think i have some new ones i might sell for $12 each.

[leadkrm]

Well his question hasn't been answered. Has anyone heard the rumor that was told to his friend about the valve guides being faulty or prone to being "loose"?

[felkman]

My thought on this and maybe I am going to far but here I go... William is asking if it is common or not because people have told him it is common even though he never read this on a forum. Ok, why would "a lot" of people make this up? It is not just one person telling you this, you say it is "a lot" and just because, you didn't read about it on a forum doesn't mean it doesn't happen! William, you are a mechanic, if this engine has only 9,000 miles on it but the oil has never been changed, you can bet those valve guides will have wear.

I don't know the cb750s at all but if he or somebody else is rebuilding the engine and the valve guides are loose, then, they need replaced regardless of if it is common or not. If he thinks the person is pulling his chain and he doesn't trust the guy rebuilding the engine, find someone else to do it that he does trust.

Another thing, Who is to say that the engine doesn't have more miles on it than that. You break a speedo, you replace it with another one that may or may not have close to the same miles on it.

There are a ton of factors here but if they need replaced, replace them, especially If he is rebuilding it anyway!

[leadkrm]

Yea good insight felk. If they are faulty too soon after they are replaced then u have an answer I suppose

[tango911]

Felkmans got it right, its def a no brainer to replace the valve guides during a rebuild along with lapping the valves themselves and or replacing the valves altogether. Ive not heard the rumor of them going bad all the time.
The best place for info Honda single over head cams is forums.sohc4.net/index.php
im no expert by any means but i am most familiar with the 750.

[williamc89]

we have some things that a engine shop has so he got them out at work and is waiting on new ones, but i it just seems weird to me , i kw engines there one of the top things i study in, a engine is a engine no matter what it is, its weird that only the exhaust valve guides wood be lose and not the intake side 2, i mean the way these are made on the 750s ud think both sides wood end up the same, they just press in. i dont think it is a comon problem,, if it was a oil issue then both side wood be like that cause the head is flat. but thanks guys,