Topic: Engine gaskets, what else?

[Ernest]

I purchased a 1974 CB 750 with a 1976 motor.  I've started it up, kicks over on the first kick but it's a 30 year old motor and I feel like I need to poke around inside it to make sure it's going to be around for 30 more.

A newbie to motorcycles so the first thing I'm going to get is a manual for this model engine. The motor leaks alittle oil.  I will be tearing the bike apart this winter and plan on at least replacing the engine gaskets and rebuilding the carbs.  While I'm opening the engine up to replace gaskets what would some other issues I might want to look into since I already have it apart? 

Since I'm already in there what else should I change?

I'm not a seasoned honda mechanic by any means so I'm looking for a "while your at it" kind of newbie check list and shopping list to get the engine running like it was new but at the same time I can't be changing things that enlist special equipment.

Please direct me to the nearest FAQ if this has already been addressed.

[cd811]

I would suggest you get over that poke and look idea. don't tear the motor down just because ya feel sorry for it. figure out where the oil is comming from. do a compression check. sounds like you got a good motor!!!

[DammitDan]

I have to agree with big orange.  "Poke around inside" is a recipe for disaster.  Trust me, I never had such a headache as when I decided to "fix" the motor when there wasn't really anything wrong with it!

[Ernest]

I do have the original engine that came with it only in peices in boxes...I was going to make it my ultimate jig saw puzzle.....I guess I can use it to satisfy my need to poke around inside.

We'll see,     If I do need to replace a gasket because of bad compression / oil leak where I would have to go beyond just the head would you want to replace anything like piston rings, crankshaft bearings, etc... or is all that stuff good for the lifetime of the bike providing you don't run it without oil or something?

[Lumbee]

...like orange said...spend $20 and buy a compressoin gauge...compression will tell u tons about the motor.  If each cylinder is 110 or better, the top end should be OK.  I did a topend rebuild this past spring, and I, like you was a newbie to wrench'n, but was able to accomplish a topend rebuilt...new gaskets and rings.  However, if I could go back I would not have replaced the rings...compression was OK on all but one cylinder, so that was $120 I could have probably saved.  I had a bent valve in one cylinder, and that was the problem.

At any rate...if it ain't broke, don't fix it.  If it runs good and its just an oil leak, just replace the gasket thats leaking.

You didn't mention how many miles it had on it.  These mills are pretty durable...you can resonably get 30K out of the top end, and closer to 100K out of the bottom end.

[cb(r)]

diddo on the comments. 
I just tore my 550 completely down.  all the guts are laying on my work table.  I had some major issues with my engine prior to tear down though.  the easy part is tearing it down the hard part is getting everything back into the right place and have it run when your done.
I am a glutton for punishment and really enjoy mechancal jigsaw puzzles.

the manual idea is a great thing to have regardless.

listen to these guys.  they wont steer you wrong.

[Dennis]

If it ain't broke,
   ......then don't F&^% with it!

I have a CB550 engine in my storage unit in pieces. I was told that the motor had about 18,000 mile on it.  I examined it briefly and didn't see any obvious reason for disassembly. So I asked the newbie where I got it why he took it apart and he answered "I dunno, seemed like a good idea!"   

[Ernest]

Dennis, so you have some feelings about this?   

I get the point.

You didn't mention how many miles it had on it.  These mills are pretty durable...you can resonably get 30K out of the top end, and closer to 100K out of the bottom end.

The bike has a 76 K6 motor in a 74 bike.  I bought it this way, I don't know how many miles were put on this motor.

Thanks