Hi from Montreal from me and my non-starting '81 CB750

[The Jimbonaut]

Hi one and all, Jimbo here in Montreal, after 5kms of pushing I finally got this beauty into my garage -

Doesn't start, flat battery...this is my winter taken care of. This is my first Honda rebuild and restore, looking forward to getting started and thanks in advance for any help I get from you guys!

High fives,

-J

 

[Motorhead]

The bike looks great, must have been taken a good care of. Are these lowered rear shocks? Good luck!

 

[The Jimbonaut]

Well, after a week (I'm no mechanic it should be said) I got her running =)

New battery, cleaned the carbs (not gonna eat your breakfast off them but good enough for starters - they'll get a rebuild later), new sparks, new gas...running like, well, not a charm, but running.

Today I ran into what may be the first snafu...following the Honda Inspection chapter in the owners manual I wanted to check the cam chain. The tensioner bolt and lock nut on the front of the engine came off way too easily and once it was out I could see some torn up metal shavings on the threads. I looked inside the hole and sure enough, the thread on the inside of the engine housing is completely stripped. Little pieces of metal in there too. That can't be good.

Any suggestions on what to do next?

 

[amc49]

Helicoil time.

Those get stripped out all the time, people just can't grasp how little torque to use on aluminum.

 

[The Jimbonaut]

You the man!

Helicoil huh, learn something every day. Especially on this forum. How do they work? Do I need machining tools to insert and secure the thing?

Should I be worried about the small aluminum filings that are stuck in that hole? I tried to get as much out as I could but there's definitely still some wedged in there tight as a tick

 

[amc49]

Wow, you are isolated not knowing what helicoils are, you must never mess with any mechanical equipment.

A helicoil is a coiled spring with wire shaped like thread, you tap a hole with same thread count but bigger hole and use a tap specifically for that one helicoil size (they absolutely do not work for anything else) to tap a larger hole in correct thread. Then the helicoil gets threaded down into hole like bolt and when done the hole is pretty much like new but with steel thread instead of aluminum and stronger as a result.

All of that relies of course on competent work, they can be screwed up in several ways. All the tools, special drill bit, one off tap, etc. come with a helicoil kit. Look them up on the net.

Yes, the swarf needs to clean out, it can seize up the tensioner stud.

 

[The Jimbonaut]

You're right about that amc, I'm pretty new to mechanics and learning as I go. Great info - I've looked into helicoils and it looks like something I might get my local shop to fix (I don't have the tools and the set up looks like money).

I'd wondered about all the oil and muck all over the front of the engine and tried to figure out where it had come from (thought it was a leaky gasket - guess it still could be) but not inclined to think that this stripped thread and loose bolt were at least partly to blame.

Thanks again,

- J