slightly distorted

[trevinoz]

Is the breather cork causing the problem? Normally this is sorted with the inner cover but your outer may be causing some warping of the inner. Just a thought.

[RichardL]

OK, I may need to be slapped for having created my own story-line here. So, as I now read you, the crank turned fine when the crankcase halves were bolted together but freezes when the outer timing cover is screwed down. That makes Trev's comment understandable. Now I want to ask if you've converted to a dynamo belt drive and have checked that both pulleys are free from interfering with the  covers.

Richard L.

[Brian]

Are you lining up the peg on the camshaft drive gear with the hole in the "top hat" ?

[Klaus]

Hi edboy,
some times ago I build up two A10 engines, converted to needlebearings and with new SRM oilpumps.
Fit the crank into the halfs and bolted together, all turns free, also the camshaft. As I fit the the Oilpump the crank locked. With an old one the crank turns free. It take some time before I understand whats wrong. The new middle of the wormdrive from the SRM  Oilpump was not in line with the middle of the crankwormdrive, so it will blocked the crank.
I have heard from an enginebuilder, that an engine was failed by cuting the drive inside the Oilpump, fited with a new SRM pump.
So please check that the pumpdrive turn free when the pump is fit.

Klaus

[RichardL]

Well, mine's working, but good advice from Klaus, nonetheless.

[Derby Rob]

hi,
 i`ve had the same problem is the past ,turned out to be the breather too tight when all bolted up !

[edboy]

thanks for replys,all good suggestions and i did check the oil pump on or off and was not the cause. i thought at first it was the cork as well but even without one the crank still locked up. this is what i meant when one simple job turned into a couple of days double checking with no easy solution. i m convinced my problem lies with case distortion and am really quite surprised no one else has had similar woes. unfortunately i m unable to continue work for a month as recovering from an op.

[RichardL]

Here's to a speedy recovery and that you feel better soon.

Richard L.

[duTch]

Quote
   only when i tighten up the outer timing cover screws especially those on the mag and dynamo edges does the crank start to lock up 

 Yup that's the bit I missed too.... for what it's worth; I also had a distorted outer cover, but went to great pains to dress it up so all surfaces mated nicely, but now two years later having it off a couple of times recently, it seems to be distorted again anyway, but doesn't seem to leak (of significance)...

 but that doesn't fix your curly problem...

[chaterlea25]

HI,
Have you tried assembling the outer cases without the idler and breather sleeve?
I found one engine where there was not enough end clearance on the idler bush faces and it tightened  up on final assembly 

John

[bikerboy]

That explains it you meant the timing cases not the crankcases thank god for that :)

And yes dutch you are going blind

[edboy]

chaterlea you were spot on the money.  the idler was proud one side and about a mm of inner bush showing. so the gear wasnt pressed on properly binding the inner case when tightened. i only noticed it as i have a spare which was fine when compared. so not cases at all. thanks for everyones input as this was a new unexpected one on me. i ve moved on now to the mag and both armatures that  i have stripped are a mess . i wonder if they are economic to repair?

[chaterlea25]

chaterlea you were spot on the money.

 

[bikerboy]

 i ve moved on now to the mag and both armatures that  i have stripped are a mess . i wonder if they are economic to repair?
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I would recommend Priory mags he doen a great job on mine for a very reasonable price

[shuswapkev]

I had something like that..assembling the engine over a few months as parts showed up and were made good...
  got my ignition housing...mad up a shorter long bolt for the low stud...put that on and moved on with the rest...week or two later ..noticed...couldn't turn that crank at all..and no idea at what time that happened..
 to shorten the story...when I turned in the long bolt on ign housing...picked up the stud and pushed that back thru into the mag gear..