73 CB 350 Top End Rebuild

Novafrk · Posted: Thu Jul 24, 2008 2:10 pm Post subject: 73 CB 350 Top End Rebuild

Hey all,

Finally got around to pulling the cam chain tensioner off to look at the wheel... What wheel... it's gone down to the metal reinforcement. So I'm going to be pulling the top end to rebuild it... I have a good honda manual, I'll be boning up on it here in a minute. I'd like to ask anyone that has replaced the cam chain tensioner before on the 350 twin if there are any special areas that I need to pay attention to?

Please let me know, and thanks in advance

Novafrk

PS: Is there a special way to post pictures? Is there a sticky on it somewhere? Every time I include a link I'm accused of trying to upload a virus.. Embarassed

NateB · Posted: Fri Jul 25, 2008 12:47 pm Post subject:

I did the same job on my twin, a 1969 CL 350. Previous owner had failed to ever adjust the cam chain through 12K miles. My roller was worn completely down, too, and the timing chain was vibrating so much it had carved a channel in the aluminum between the cylinders. The aluminum shavings, meanwhile, had completely filled up the centrifugal oil filter, which meant that no oil was getting to the top end, which meant I had to replace almost everything up there: rocker arms and shafts, camshaft, camcase housing, etc. (Got all of that very cheap on e-bay.) Went for a rebore and fresh pistons, too, which was the priciest thing.

Only thing I can remember that was tricky about the job was making sure not to drop those little rubber inserts that hold the cam roller in place down into the motor. They're tiny, and they're just held in by gravity. My chilton book (which had a great step by step top end overhaul section) suggested a drop of gasket cement to help hold them in while you reassemble everything. Also, the cam sprocket has two bolts that look alike, but one is shouldered and one isn't, so don't mix them up. Getting the cylinders back down over the pistons is not that hard on this bike. Oh yeah, I almost shot my eye out by releasing the tensioner adjuster bolt all the way while the tensioner was off the bike. That's a pretty strong spring in there.

Ran tons better when I was done. Good luck.

Novafrk · Posted: Tue Jul 29, 2008 7:29 pm Post subject:

Thanks Nate,

The disassembly was easy... and I almost lost one of those little inserts you were talking about. I'm replacing the factory set up with one of the bore tech teflon ones... I don't ever want to mess with it again. Should get the parts pretty soon. I'm gong to rering it, only because one side was frozen when I first got the bike... figure a quick hone and new rings it should be right as rain... I just got the tank back from my uncle... I'm going to try to put the link to my photobucket account but it always accuses me of uploading a virus. Here goes...

http://s277.photobucket.com/albums/kk43/Novafrk/CB350G%20rebuild/

NateB · Posted: Tue Jul 29, 2008 8:36 pm Post subject:

Wow, you are really doing it right. Tank looks cool! Here's a guy you might get a kick out of: www.oldmanhonda.com

Novafrk · Posted: Tue Aug 05, 2008 9:23 pm Post subject:

Thanks Nate,

Things are coming along. I've got the engine mostly put back together... but I'm hitting a snag... I have a vauge recollection of reading something on the hondatwins site that if you use the aftermarket cam chain tensioner that you have to replace the cam chain with one from a 750... does this ring a bell to anyone out there? I'll let everyone know when I find out.

Novafrk

http://i277.photobucket.com/albums/kk43/Novafrk/CB350G%20rebuild/100_2723.jpg

Johnny5 · Posted: Wed Aug 06, 2008 5:29 am Post subject:

Sorry, dont know about the cam chain thing, but wanted to let you know your bike is starting to look really good. Keep posting your progress.

You might be able to do a search over at www.dotheton.com for your question.

NateB · Posted: Wed Aug 06, 2008 8:31 am Post subject:

Haven't heard about switching the chain.

Novafrk · Posted: Wed Aug 27, 2008 5:57 pm Post subject:

Hello all,

I've been very busy working on the honda. Here are the latest pictures. As far as swapping the chain, I emailed bore tech and they said you could use the stock chain. Everything should go together.. Come to find out I had pinched the cylinder gasket in the area where the front cam chain guide goes. Any way third time back apart I found it and it went together with gentle taps of a rubber mallet just like it came apart. While I was inside the engine I honed the cylinders and put new rings in her. Everything seems happy so here's to fingers crossed.

This is how she sits right now... I'm going to end up running the factory pipes with the mufflers for this year. I'm missing one of the collars for the other drag pipe. I'll fab something over the winter and run the drag pipes in the spring.

Nova

Johnny5 · Posted: Wed Aug 27, 2008 6:09 pm Post subject:

Lookin really good. She's beggin for a custom seat of some sort to really pull it together. What did you use to paint the engine? I painted my side covers with high temp Duplicolor paint and after a month, it's holding up great.

Novafrk · Posted: Wed Aug 27, 2008 8:48 pm Post subject:

Thanks! I used VHT 1200° AL Header Paint. I hope it holds up well too. I've got a tore up seat/pan that I plan on modifying for my wife... It will have that kind of cafe bump stop look for her... with the factory seat I'm very flat footed on the bike... my wife is on the balls of her feet and would like a little more control. She will most likely be riding this in the spring. So with just the swapping of the seat either of us can ride it BRILLIANT!

Novafrk · Posted: Wed Sep 03, 2008 8:43 pm Post subject:

Should have the bike running tomorrow night... misplaced an exhaust pipe gasket. Couldn't get one till Thurs. Just about everything else is done.

Novafrk · Posted: Wed Sep 03, 2008 8:54 pm Post subject:

almost finished...

Johnny5 · Posted: Thu Sep 04, 2008 5:38 am Post subject:

I wonder if painting the headers black would fit the bike better. Looking good.

Novafrk · Posted: Thu Sep 11, 2008 9:32 pm Post subject:

I've actually been thinking about that... I have some black pipe wrap I'm thinking about trying out... Those pipes sure get hot.

This is the latest... I've been riding her back and forth to work... pretty sweet.

Nova

Johnny5 · Posted: Fri Sep 12, 2008 5:35 am Post subject:

What baffles are those? What do they sound like?