[Dennisgb]

I finally got back to replacing the crankcase gasket on my 500 Bullet.

When I tighten the timing cover screws there is more tension on the crank when I try to rotate it. It turns but when I loosen the screws it turns freely. I replaced the worm gear with a bonded rubber cork seal. Would this cause tension on the crankshaft?

engine by dennisgb, on Flickr

[ace.cafe]

Maybe check the depth of engagement of the worm gear and paddle on the oil pump drive.

[Adrian II]

If the crank spun freely with the crankcases fully bolted up and only got harder to turn with the timing side fully assembled the problem is unlikely to be the crank.

Is that a green timing cover gasket I see?

A lot of these seem to have been made of thinner material than OEM, I had the same problem with a 5 speed gearbox cover gasket and of the same material causing the kickstart to bind.

On the timing cover front, if your oil pump worm nut to oil pump spindle tolerances were fine before (and the bonded rubber worm nut usually has MORE clearance, not less) the thinner timing cover gasket has stolen the clearance between the cam gear or shims and the cam spindle housing face in the timing cover, making the engine harder to turn over. Try fewer or thinner shims on the cams.

A.

[tooseevee]

Is that a green timing cover gasket I see?

A lot of these seem to have been made of thinner material than OEM, I had the same problem with a 5 speed gearbox cover gasket and of the same material causing the kickstart to bind.

A.

          I got a lot of those green ones in the spare gasket kits I ordered from India. The only ones I've used were Valve Cover and Primary Case; no leaks, but those have little effect on tolerances.

[ace.cafe]

Depending on the distance to tight, using 2 of the thin timing cover gaskets may be an option.

[mrunderhill1975a]

The video below shows a similar problem, it turned out to be the shims on the timing gears were too thick.  As mentioned above, too thin gasket may also be problematic.


https://www.youtube.com/watch?v=j2019jn99Ao

[Dennisgb]

Thanks so much for the great responses.

This is what I suspected.

Pretty crappy that a gasket thickness can control a critical tolerance. Adding an additional gasket is a concern because the potential of too much slop.

I didn't realize there were different sizes of shim washers. I just used the ones that were in there since the engine was stock.

I will do some measurements and see what's up. I think I can use a dial indicator to figure out the interference.

[ace.cafe]

Thanks so much for the great responses.

This is what I suspected.

Pretty crappy that a gasket thickness can control a critical tolerance. Adding an additional gasket is a concern because the potential of too much slop.

I didn't realize there were different sizes of shim washers. I just used the ones that were in there since the engine was stock.

I will do some measurements and see what's up. I think I can use a dial indicator to figure out the interference.

When the bikes were made, there were different thicknesses of gaskets, and the engine builder selected what was needed from his parts stock.
After they were no longer being made, aftermarket gasket kits were just made the right general shape, and no real concern about thickness of the timing cover gasket.
When I was coaching people doing Fireball builds, I would always try to get them to carefully remove the timing cover, so as to hopefully not destroy the gasket. The black rubber ones were almost impossible to find.

It is important to remember that this is a design from around the 1930s, and engines were built by "fitters" that hand assembled the parts according to fit of the various parts that were not very precisely manufactured. In India, they just continued to build them in the old ways.

[Dennisgb]

It is important to remember that this is a design from around the 1930s, and engines were built by "fitters" that hand assembled the parts according to fit of the various parts that were not very precisely manufactured. In India, they just continued to build them in the old ways.

Yes, I probably should have said "pretty funny". I've been working on British bikes for years and understand many of the quirks of these older machines. Each has there own, but these Royal Enfield's are new to me. This Forum has been very helpful in figuring things out. They are pretty basic and simple.

You can see my Norton in the background of the picture above BTW. 

[Dennisgb]

the interference is the cam gears. there is only a few thou to work with. they have .005 shims front and back. thinking about just leaving the back shims out. will that cause any issues

[ace.cafe]

Should be ok.

[Dennisgb]

Should be ok.

thanks. thought it better to let the cams ride on the shaft boss rather than the aluminum on the cover.