Very puzzling!

I wonder if someone can help with an explanation for the following. I have just re-assembled my Lister D after taking it to pieces to examine for wear and tear, also to de-rust and paint the bits. When I tried to to turn the engine over it was very, very stiff and I could only just move it on the handle. When I loosen off the five nuts behind the flywheel holding the crankshaft into the crankcase half a turn it becomes free and turns over normally. I just can't understand what cold be causing such a difference in stiffness with such a small amount of adjustment. I would be grateful if anyone could explain whats going on?
Jim

Did you put the con rod back in the right way round ??

An interesting point and I can only say I think so as when I put it in the other way the stiffness was worse. I don't actually know which way it should go in. One face has the Lister name stamped on it and I initially put this facing towards the flywheel, then reversed it. As it seems much less stiff yjis way in so I assumed this is correct.
Jim

Have you removed the magneto/governor/cam unit? Are your main bearing seated correctly? Don't forget to remove the spark plug when trying to turn the crank with the magneto/governor unit removed.

Simon

Everything has been removed and hopefully reassembled ok. The turn over is quite free with all the bits and pieces in and out so to speak until I tighten the 5 bolts holding in the camshft the last quarter - half turn. The turn over then becomes really stiff. It was the same thing with the head off. I checked to see if anything wasn't seated, mated or out f line but couldn't find anything obvious. Its got me completely stumped.
Jim

A similar thing happened with my Villiers Mk 20 engine. I had taken everything out, put it all back together correctly and there was a lot of stiffness when I was turning it over. When I loosened some bolts, everything was fine though. All I did was lubed everything up, tightened it back up and ran it for a bit. Seemed to sort itself out as it turns over fine now!

I've recently put my Petter M back together I also had a similar problem I first assembled it with gaskets between the crank case and bearing housings the crank was binding yet I knew the clearances where good and there was too much end float, pulled it apart again and used instant gasket and now it is perfect but I can't explain why.

As NoelA suggests, it sounds like an end float issue.  Are the gaskets the same thickness as before?  Or maybe something like a press fit bush or similar isn't quite in the exact same place as before, may only be a few thou, but boy what a difference that can make, (ie clearance to interference!).
Can you easily get a feeler gauge between the cover and the gasket with the bolts just lightly finger tight?  If so tightening the bolts will clamp the shaft endways and make it stiff.  Then work back from there to find the culprit, could be any of a number of things not quite where they should be in the assembly.
If you really can't find it, try a slightly thicker gasket (by the thickness of the largest feeler,that will fit, plus at least the max recommended end float for the camshaft) under the cover.
If that is free, run it briefly, if it rattles, try it with the standard gasket, it may have seated something back into place.  Otherwise keep checking the end float for awhile as it may settle in but not rattle and need to have an original thickness gasket back.

Cheers
Darryl

Hi, Jim... If you haven't already, you could try giving the outer casings a sharp tap or two with a small ball-pein hammer to make sure that things such as bearings and or bushes have seated fully. I don't know the motor so can't be specific. Tap in the vicinity of each bearing/bush.

Cheers,
Bruce.

What can happen if you tap cast metal with a hammer ? We tapped our old cast iron bath to get it downstairs, and it broke into 2 bits.

A GENTLE TAP is to be performed using only WRIST ACTION. If you damage the paintwork you are being too aggressive. The tapping procedure is not just my own idea, but normal practice. Incidentally, cast-iron bathtubs are quite valuable in this area. Especially if not legless, chipped, or BROKEN IN HALF BY BIG HAMMERS AND "GENTLE TAPS" !!!

Cheers from the Colonies,
Bruce.

freethought wrote:An interesting point and I can only say I think so as when I put it in the other way the stiffness was worse. I don't actually know which way it should go in. One face has the Lister name stamped on it and I initially put this facing towards the flywheel, then reversed it. As it seems much less stiff yjis way in so I assumed this is correct.
Jim  

In the Lister D the big end bearing is flush with the con rod on one side and sticks out beyond the con rod on the other side.
From memory the flush side of the bearing goes against the crank web.

A thank you to Darryl and everyone else for the help. It was the gasket. I ordered a set from Stationary Engine Parts on ebay and assumed they would be OK. I can only find a small part of the original gasket but its quite a bit thinner than the replacement. I removed the new gasket and put the crank back and it turns over as normal. I wouldn't have believed that such a small difference in a gasket could have such a major effect. I shall try making a new one out of brown paper.
Jim

Hello Jim, I have to say this has been a good thread - As you say you buy something as simple as a gasket off the 'net and expect it to perform  - but you would not automatically think it would have such a drastic effect. It would not enter my mind to look at a gasket when trying to solve the issue - just glad it was you and not me!

You live and learn!

Thanks for keeping us up to date - very useful!

P.S I have seen lots of different thickness gasket papers on fleabay - so should be simle to find the one you want.

Best

Hamish