• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Would like some expert advice

dan1951

CB750 Addict
Messages
341
Reaction score
0
Points
16
Location
armada mi. 48005
Been a long while since been on here, I need some advice for a 1971 sohc I want to send My cylinder out to Cycle X for a next size overbore and get a set of pistons and rings from them. My question is would it be a bad move to use the original cam chain with 8,200 miles I hate to tear the bottom end apart? I will be replacing the tensioner and arp studs. Am I pushing it Do not plan to hot rod it, Thanks in advance Guys
 
So 8200 since the chain was replaced? Just keep in mind the stock chain is one of the weak spots along with the cylinder studs.
 
Thanks D.D. for ringing in, The chain is original that came with the bike the miles are accurate, Any alternative to not disassembling the bottom end such as a linked chain sold by CB750 supply?
 
Chain wear is directly linked to how tight it gets kept in tension, if you are on top of it it lasts longer.

Link you have to do yourself is fine if you know what the staked part is supposed to be shaped like. I've done them before and no trouble. The chain itself needs to be a good brand. They even may make a staking tool now to do that.

True 8200 is not a lot of miles, I count 20K before worrying, but you need to think about the number of times you get to redline or more, that is what drops the life.
 
Thanks AMC for the advice very much appreciated. I think I will look for a good brand of chain and purchase the staking tool. The bottom end of the engine has no leaks, noises, and great oil pressure that's why I do not want to disassemble it. Again thanks
 
I dont like the staked chains, to many things to go wrong if you dont do it right. Plus you are just putting another weak leak chain back in the motor. I would leave it unless you split the case to put a heavy duty chain in it.
 
Having said that I would 1st choice also likely reuse the same chain if it hasn't been revved forever, it is already proven out. 8K not being that many miles. Age from sitting will not affect that part.

I'd use that chain up some more. Even more if you don't abuse it.
 
Slept on the idea overnight and decided to leave it. The compression is 125 to 130psi dry wet check 170 plus so that's an issue. At My age I think the chain might outlast Me. I was always one to perform preventive maintainance on every thing I own but I think this is one thing I will leave alone. Do not beat the tar out of stuff like I did long ago. But I value both of Your opinions. Thank You Both
 
Good on you. I do the same now.

I was always ahead on maintenance on the cars and bikes and spent some guessing parts had to be better than they do. Getting older I now use many parts longer than I used to and still no fails if you are smart about it. The parts that WERE going to break will do so anyway. And now it's getting where weird stuff breaks way ahead of time now what with the cheapness they build into them, you can't tell often what the weak parts are any more. I know we have utter fits with NEW timing chains on the DOHC, you now run the old one as long as you can because the new one can fail in a month after putting it in, they went to very small pins in them. Lots of complaints and broken motors.
 
D.D. waiting for My Grandson to get some time off from the dealership to give Me a hand removing the motor got some heart issues and others going on. Let Ya know when I get it apart.
 
With that few miles what makes you think it needs to be bored? It will run on that compression you have. Adding oil can be misleading. With the small bore size of these engines people put way too much oil in during these tests, everyone remembers the old days when they said throw a teaspoon or whatever amount in the cylinders, well a teaspoon is a huge amount in this small of a bore. To much oil takes up a lot of cylinder volume and makes it have false high compression. I would run it and see if compression improves. The stuff cant be worn out with that few of miles unless it has some bad rust pitting in the cylinders, if not rusty hone the cylinders and throw some new rings in it.
 
The friend I got It from passed away years ago He a blew a hole in engine case from a lost chain He got cases as close to the factory numbers and had a dealer swap all the parts I hate to talk ill of the passed one but You almost had to pry a buck from Him Yet He paid $1100 for the swap years ago. I am just guessing but I think He had them put the original rings and ect. back in the engine. I have the work order but no mention of parts involved. I know complete No No.
 
Back
Top