I see what you meant when you posted on my engine knocking problem. :shock: I haven't so much as had the key in the ignition since you and Jim told me to park it.

 

It's nice to know some people listen.

 

You should only just be able to see the merest smear on the case faces before assembly, as they are machined pretty much perfect from new.

 

Yes, Nige. I posted this for those who don't know/realize the damage from using too much. I got the bike with the blown engine and am just now delving into it. I thought it might make a point. We do learn from others on this site. I was just doing my part to pay back for some of the knowledge I have amassed from all on this site. Even though I am a retired auto technician, and most of my experience has been with brits,I am no Honda motorcycle expert by any means.

 

Aviation Permatex...#3

 

Yes, Nige. I posted this for those who don't know/realize the damage from using too much. I got the bike with the blown engine and am just now delving into it. I thought it might make a point. We do learn from others on this site. I was just doing my part to pay back for some of the knowledge I have amassed from all on this site. Even though I am a retired auto technician, and most of my experience has been with brits,I am no Honda motorcycle expert by any means.

Yes Brit bikes (that is classic not new) always has oil leak issues. Vertical split crank cases did not help and the sand casting was not as good as Hondas Investment cast casings. A good piece of advice to pass on. It's such a pain if you have done everything on the engine put it back together and then an oilway gets blocked down the line due to sealant .

 

The best product Iv'e ever used was Yamabond. I believe it's liquid vinyl. It's beautiful for sealing old, crappy, warped British crankcases and stuff But, It will skin over if you screw around with assembly after you apply it. Silicone is a wonderful invention if you understand it. The problem is it skins over almost immediately and if it's applied too generously will squeeze out and come loose internally and get picked up by the oil pump or an oil journal. And we all know what that does. What I use on air cooled engines has been around forever. Permatex aircraft #3. It's a brown sticky liquid w/a brush. It won't harden, ever,really, so it's the perfect sealant. The "aircraft" part should give you a hint. When you think about it, basically you have the same engine construction as a Cessna. I also use Aeroshell 50W because it doesn't turn to water when it gets really hot. On another vein, anaerobic sealants are perfect if you have perfectly mated surfaces. Being Japanese, chances are good. So, if you have perfectly clean mated surfaces, try an anaerobic glue. It will keep the tolerances described by the factory intact and increase your chances of success....

 

From what I've read here, yamabond is the same as hondabond and suzukibond.

 

Probably. I discovered Yamabond 30 years ago when I had Nortons and Triumphs and it was a Godsend. It's thick tho and the problem w/case halves is that if you have a sealant that doesn't compress to nothing you risk having tolerances that exceed factory specs and a main bearing could possibly spin. Don't get me wrong. I think silicone is wonderful, in the right application. The thing is, case halve joining is not the proper application.

 

Probably. I discovered Yamabond 30 years ago when I had Nortons and Triumphs and it was a Godsend. It's thick tho and the problem w/case halves is that if you have a sealant that doesn't compress to nothing you risk having tolerances that exceed factory specs and a main bearing could possibly spin. Don't get me wrong. I think silicone is wonderful, in the right application. The thing is, case halve joining is not the proper application.

That was exactly what I was trying to project to those that were new to this kind of engine.
I learned it almost fifty years ago on a suzuki.
I wanted to show what misuse of sealant by a PO did to a good engine.
I may post more pics of that engine since I now have it split apart.

 

Here's some more pix.

 

Real grenade engine there, not as bad as I thought it would be though. Expected the crank carrier to be broken as well

 

Real grenade engine there, not as bad as I thought it would be though. Expected the crank carrier to be broken as well

It is..........just didn't get a pic of the underside. In the bottom left of the shrapnel and balance shaft pic, you can see some of the aluminum from the carrier.

 

Boogers, that means you have to replace the upper case as well unless it can be welded. The carrier and upper case are machined for the crankshaft bearing bore as a single unit so they become a matched pair. If you can get it welded be sure to set the crank and bearings in the case and torque the carrier first to keep alignment

 

Upper case is done too. You can't see it well in the last pic, but where the front balance shaft looks bent, it's actually broken with part of the case . It also broke off half of the boss for the front carrier bolt. I had/have somebody that was getting me another engine. I am going to salvage as many spares as I can out of this mess. On the good side, the bolts look good..........LOL. Tranny looks real good. Haven't checked the head yet. Also, how does one tell if there is rubber damping on the balance weights? These don't look like they have any rubber. I don't have any to compare them to.

 

The rubber ones are multi piece secured with a large circlip. I think all 400 are rubber type. All of the 450's are solid.

 

If I replace the balancers in my CM400 with ones from a CM450 or CB450, is it just a straight swap? Or do I need to modify them to make them fit? I've heard that the balancers in the 450 are an improvement since they are a single piece.

 

It's a straight swap.