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Originally Posted by aiden65
As for crankshaft end play I have 0.006”. I understand the specs are 0.0015 to 0.003 on a fresh rebuild but have read accounts of not hearing knocking until 0.015 or more. What would be your suggestion? Pull the stator and shim or just monitor for now?
Unfortunately, the cases have to be split to shim the crankshaft end float. The .0015" - 003" figure is for initial assembly. From (unreliable) memory, the workshop manual lists.005" as the upper limit, so .006" is probably sort of alright. The bigger concern is whether the sludge trap was cleaned out. Many of the failures attributed to a worn timing side bush were more likely to have been caused by a blocked sludge trap.

Those engines are pretty tough, and will tolerate all sorts of things out of spec if they aren't thrashed or lugged.

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aiden65 Offline OP
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Thanks Shane,
I think since it isn’t making any noise I may see what happens unless you think that’s just foolish. I just would like to take it for at least one decent ride.
It is not going to be thrashed on, I have a Ducati for that. Mostly to work and back and some weekend rides.

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Pulling the stator (or rotor) and shimming behind the rotor will only effect the primary chain alignment. You’d have to remove the bearing and split the cases the change the end float.

I agree with Shane, I’ve seen a good bike with more than 0.006” end float and my biggest concern would be the sludge trap, unless you know it’s history.


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.006" end float is in the "keep am eye on it" category.
We took a 1970 Lightning with .006" end float down to the BSA International at Halls Gap in 2018. It was ridden about half of the 3-day ride to the rally, then did most of the runs at the rally. Most of that was on quiet country roads, so sitting around the 100 km/h (just over 60 mph) speed limit It's since moved to Queensland, and was still going strong last I heard.

How did you measure the end float? I remove the chain case and the inner and outer timing covers and use a dial gauge on an arm connected to a "post" screwed into one of the tapped holes in the crankcase. That also allows checking of vertical play in the timing side bush.
It's fiddly and time consuming, so really only worthwhile when you're putting the engine together in the first place or you want to be really, really careful.

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To measure the end float I used a dial indicator with a magnetic base, tapped the crank to the right with a rubber mallet, zeroed the indicator then pulled the sump cover and levered to the left on the flywheel. I repeated this a few times with consistent results.
Can’t say about the sludge trap, tried to call the previous owner with no response. I don’t suppose there is any way to know without splitting the case.

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Originally Posted by aiden65
To measure the end float I used a dial indicator with a magnetic base, tapped the crank to the right with a rubber mallet, zeroed the indicator then pulled the sump cover and levered to the left on the flywheel. I repeated this a few times with consistent results.
That's less hassle than taking the timing covers off.

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In thinking about some of your comments and given that half of the attachments have already been removed in getting the cylinder head off I am thinking maybe it is time to split the cases to remove the unknowns.
My question is whether you would reuse the bearings that the previous owner put on (only as evidenced by having the old shells in the parts box)?
Would still remove to evaluate the journals, plastigage, etc. Not trying to cheap out after getting to that point, but don’t want to replace new parts if there is no harm.
Thank you,
Aiden

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If everything is in spec and the surfaces appear to have little wear, I don't see what not.

Replace the big-end nuts as a matter of course, and be prepared to replace the bolts as well if they are showing their age. It's always a juggling act as to which components can be safely re-used and which should be replaced.

When we were younger and put in lots of miles rather less sedately, we used to re-use as many of the existing parts as possible. As we have become older and more "responsible", we tend to replace more bits even though our riding styles have mellowed smile

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Got the cases split and by the looks of the plug for the sludge trap the previous owner tried but was unsuccessful in getting it out. The trap was pretty much empty though. Bearings and journals, gearbox gears, etc. were in good shape too. Well, at least now I know.
Any suggestions for other things to make sure of before I reassemble?

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Make sure the gearbox layshaft endfloat is no more than 0.003", keeping this correct really helps the gearchange.


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well the gearbox isnt going to creat popping and backfiring.

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Thanks Gavin, I am going through your previous posts for the procedure.
Hacksaw, I think Slipping the pushrod from the valve sticking was the primary problem, but based on the recommendation of others to check the sludge trap I disassembled. Just want to do whatever I can while it is apart so I don’t have to do it again anytime soon.
Thanks,
Aiden

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Another dumb question regarding crank end float. When I took the roller bearing off there were 3 shims at 0.010” each outside of the roller bearing and none in the shim cup. Are these for final drive alignment? Since I need to make up 0.003, can I have just one 3 thou shim in the cup?

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There are two sets of shims, one for the crank endfloat (in the shim cup), the other for aligning the engine and clutch sprockets (between the engine sprocket and distance piece).

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Got it, thanks.
As for layshaft end float, I have 0.010”, and my thrust washer is .123. Max available is .125. Anything special about that washer or can I just try to get something from the hardware store to make work?

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So long as the lay shaft thrust shim/ washer is flat and made of steel pretty much anything is better than excess end float, something with the correct ID and OD can be lapped down on an oil stone if it is over thick.
While you are in there stone flat all gears with female dogs. Bitch holes? Polish the cam plate around the plunger track and selector fork areas , and cut 2 turns of the index plunger spring.

Check the primary drive side is aligned properly ( a steel rule held against the primary offered to the clutch chainwheel with no chain will tell the truth, get it within 5 thou), check all steel clutch plates are truly flat, reject any that will pass a 3 thou feeler blade.
look really closely at the clutch hub cush drive, its often passed over, wear internally gives a lot of bother.


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Thanks for the good info. Will do what you recommend. With regards to the “bitch holes,” (nice) do you mean to lap the flat face of the gear with the series of drilled holes that articulate with the adjacent gear on the same shaft? I don’t have the terminology, sorry.

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I look /feel for burrs where the male dogs engage in the female receptacles ( bitch holes), dress these flat with an oil stone, low tech.
There are two sliding gears in the box , each sliding gear has male dogs, I am specifically referring to the mating gears that the sliding gears engage with, if the clutch has been badly adjusted or / and the user is heavy footed , these take a beating, burrs on these faces prevent clean shifts.

Last edited by gavin eisler; 01/13/21 4:10 am.

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