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'94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Fri Nov 06, 2020 10:30 am
by jawa-enfield
Question 1;
On the drive side of the crankshaft are 2 bearings; A roller bearing and a ball bearing.

The Snidal manual says ball bearing in the outer fitting and roller bearing at the inner side.
But the drawing of our host says the other way?
https://www.hitchcocksmotorcycles.com/p ... pages/1616

How should it be? My 'gut's ays roller bearing on the inside,,

Further i am looking for tips to optimize the engine.. Not in power, but in reliability..
Planning so far;
-Swap bearings
-Install 535 exhaust valve and guide
-UK-made piston of our host..
More things i should/could do?

Am gratefull for tips & hints!

Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Fri Nov 06, 2020 12:09 pm
by Beezabryan
1994 Bullet 500 engine
Rollers inboard, balls outboard.

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Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Fri Nov 06, 2020 12:25 pm
by jawa-enfield
Thanks!!, i thought so much.. and there is no other possibility if you have to mount the inner race from the roller bearing on the crankshaft end before assembling??
Sometimes the pieces of the puzzle fit after more coffee...

another question comes to mind.. Between the both (outer) crankshaft bearings(left and right) and oil seal (not very clear on every drawing) are 'Thrust washers'?

These were NOT present in my engine..
What is the fuction of these and should i install them anyway?? Where would they go exactly?

(email notification does not work, is there a trick to it?)

Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sat Nov 07, 2020 8:32 am
by Beezabryan
There are a pair of circlips but no 'Thrust washers'
See item 10 -
https://www.hitchcocksmotorcycles.com/p ... pages/1616


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Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sat Nov 07, 2020 9:39 am
by Haggis
There appears to be spacers between the bearings.
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Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sat Nov 07, 2020 1:24 pm
by stinkwheel
There is a thin thrust washer (more like a shim) that goes on the timing and drive shafts before the bearing inner race (sits between the crank web and the bearing race). If you couldn't see one, it might be stuck to the crank? They are very thin steel.

Here's one in place before fitting the race.
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Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sun Nov 08, 2020 3:05 pm
by jawa-enfield
@ stinkwheel, yes these are present..
In meanwhile i have the strong suspicion that the layshaft is at fault of popping out of gears, the studs seems VERY round and 'pushing' gears aside.

Further this bike seems/is possible to be an import version.
The layshaft bearings are not made of Bronze like my other bullet's.

Is it better to replace these for bronze ones?
(and how can you filter bad india-gearbox parts from the good ones?)

Further i am wondering if there are alternative valvle springs for the bullet 500 which have less chance to break?

Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sun Nov 08, 2020 4:39 pm
by stinkwheel
My UK market bikes both have iron bushings on the layshaft. I will be changing them next time I'm in there because they tend to "pick up" the kickstart under hard acceleration when the gearbox is hot, melt the rubber onto the exhaust then hit you on the back of the leg when you close the throttle. The bronze replacements are fairly inexpensive.

I wonder if fitting lighter, more balanced rockers would reduce load on valve springs and valvegear in general? The samrat rockers our hosts sell are like they were made on a different planet compared to the standard ones. I never weighed them but there must be half the reciprocating mass and properly balanced.

Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Sun Nov 08, 2020 6:35 pm
by Wheaters
I took a whole lot of excess metal off my bike’s rocker arms, using my bench grinder first and then various files to smooth them and remove stress raisers. I also lapped in their shafts using fine grinding paste because it was obvious they were running on high spots and it was possible to feel places across their range of movement where they had higher friction. At that stage the bike had only run about 3,500 miles. It’s now done 16,000 and it seems to thrive on revs.

Re: '94 bullet engine overhaul, need advice and which crankshaft bearing goes where?

Posted: Mon Nov 09, 2020 12:12 am
by stinkwheel
Standard rocker on left, samrat on right.
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