Friday, July 23

Oh shit

Remember the cork? It was filling the timing hole in the crankcase after the plug dropped out.

Now, it vaguely occurred to me that it was strange that a bolt could back itself out like that, but apparently it happens, so I just ordered a plug for a '52.

It didn't fit, which should have been my second clue.

I then ordered an oversize plug, not even thinking to inspect the timing hole itself. And then when I came to fit it, I realised that the hole's threads are knackered. I'm guessing someone just forced in a bigger plug at some time without tapping the hole properly. Or something.

After a bit of online research I realised that this is fairly common, isn't an easy fix and that some people do run corks in their ruined timing holes... permanently.

Hmmm. Any ideas? I really don't want to be splitting cases on a great running bike...

12 comments:

Steve@strathbran said...

i'd be running with the cork til the motor needs pulling apart, and carry a spare one!

Burt Munro broke records with a cork for a fuel cap ;-)

Hermann said...

I'm probably not going to explain this well, but could you make a bung with a plate fitted that bends over and is held by two screws on the side. A bit more fiddly but might work.

Tony d. said...

yea. cork.

Johnny said...

Or you could talk to a good engineering shop. I'm sure there are threadserts (not crappy helicoils) you can have fitted that won't push any swarf into your case. Bit more pricey at about £40 but cheaper than a complete new gasket set and the down time of a strip.

mp said...

Can you time cert or heicoil the thing?

Gray Mitchell said...

Boat plugs?

http://www.iboats.com/Seasense-Baitwell-Bailer-Plugs/dm/cart_id.192491182--session_id.896061694--view_id.56065

Anonymous said...

Weld it up, and re-tap it.

andy said...

I bet if you ran a tap coverd in grease it would straighten it out enough to run the proper plug in.

Or take a rubber cork, drill a hole down the center. Take a carats bolt and place it so the head is on the small side of the cork. Now on the outside run a washer and a wing nut. Insert it into the motor and tighten the wingnut and it will force the rubber out in turn holding the plug into the case.

tiptopdadddy said...

I would try a pipe plug. The first 3-4 threads are standard size then it expands slightly. A little teflon tape or blue loctite and you should be in business. I have used them to plug tank bungs and intake manifolds. They work quite well. You can get them in the plumbing section of the hardware store, usually for less than a buck. Or, just stick with the cork.

Rowan said...

i've seen this done and it works Guy... buy a rubber cork from a home brewers supplies... trim so it does not go too deep (passed the thread), half drill the outer center with a very small hole and then push the rubber cork (read bung) into the inspection hole... screw in a very short fat self tapping course screw which expands the bung into the hole.... it will last forever and is simple to remove to do your timing

it works mate and costs pennys, i've run hundreds of miles with one and no problems... i cannot stress enough how good this fix is

PM me if you dont quite understand what i mean

knukkel said...

I did the tap covered in grease trick some yeas ago on my bike and it worked fine. Take your time though!

special'79 said...

I did the treatment in this shovelhead forum thread. Works perfectly, super easy.

http://www.shovelhead.us/forum/showthread.php?t=8619