Topic: 350F cam chain tensioner trouble.

[Exbex1]

I purchased a 72 350F at the beginning of the season. It’s got a little over 13,000 indicated miles. I'm assuming that’s accurate, but cannot be certain. I love it. It runs great. It sounds great. I've put about 600 miles on it with zero issues. On the last 2 or so rides, I thought that the cam chain was louder than it should be. I looked in my manual and read about adjusting it. This is where things go badly, quickly. I was not aware of the issues on this motor with the tensioning system.
Ill cut to the chase. I broke the entire bolt off when I was tightening the lock nut. I swear I didn’t reef on it. Dumb, I know. I was able to drill a hole and get an ez out in there, but proceeded to break that off too. A bad day. About as bad as it gets. Yesterday I spent 2 hours with a Dremel and various bits grinding away. No luck. I made progress but not even close to being able to remove the bolt.

Finally my question! Thank you for reading this far. I'm sunk correct? I have to split the lower case to get at the back of that broken off bolt right? It’s tight against the adjusting rod so the system is not working. If I do have to split it, I might as well buy the “new” horseshoe and the aftermarket tensioner bolt that goes in from the top hole?

Question 2. Can I ride it the way it is? It’s not horribly loud. I assume the chain is loose but am not sure.

I'd love to hear from anyone that has gone down this road. Not necessarily about my ham fisted mechanic skills, but thoughts about getting my little buddy correct again!

Thank you.

[bryanj]

Yes you now have to split the cases, with all the gaskets and seals required.
Personaly i would fit new cam chain, primary chain(kawasaki one at half honda price) and damper rubbers in primary drive.
Horseshoe only needed if the pivot is siezed due to chain being loose and the kit you talk of is not what you need as its way too easy to overtighten the cam chain, you need the repair kit from noxandrattles.co.uk

If for some reason they wont post to you i will for whatever the cost is

[Exbex1]

Thank you. I ordered the part. Very nice guy. It should be in tomorrow’s mail.
I'm going to try a left hand thread 5mm bit, but I'm not expecting much success.
It looks like I'll get a look inside the motor this winter.
Stand by for many unforeseen calamities!

[bryanj]

All you need extra is the correct m10 tap

[Exbex1]

Roger that.
Thanks.

[Exbex1]

Hello again. The tensioner is in the mail from noxandrattles. Thank you for showing it to me.
I ordered a good set of left twist drill bits in a final attempt at the broken off tensioner bolt.
If by some miracle I'm successful at extracting it, would you try to drill and retap for the new tensioner with the motor in the bike? I have access to a good lift and with the oil filter housing and exhaust removed, I think I'd have a pretty clean look at it. I'm really trying to avoid busting into the engine. It runs great other than my perception of a noisy cam chain. I hate to jinx it by splitting it open if it can be avoided. If not, so be it.
My concern is the shavings? I'm worried about getting them inside the case.
Thanks for any advice.
Tom

[bryanj]

No i wouldnt, the horeshoe is so notorious for siezing the pivot pin plus the shavings would worry me

[schonc]

Tom,

I'm in a very similar situation and following along.

I started with a basket 350F with a pre-sheared tension adjuster.

I also broke an extractor and have had no luck with the more civilized removal of the broken screw. My best shot at it was probably a torx bit gently hammer into a pilot hole.

Next, less civil attempt, was to drill out the entire screw. I was just using a hand drill; that wasn't steady enough. I aborted that pretty quickly once I could tell the bit wanted to wander off the screw.

Lucky for me, I have a CNC machining department at work. I'm going to see if I can get a helping hand to fix the case up to the manual mill one day after work.

Question for those who have already got past this problem. Can I still disassemble the cam assembly with the tensioner done up? I suppose I could always cut the chain but I already feel bad about trying to ham-fisted-ly drill out the screw .

Clay

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