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Can a damaged crank be repaired or buy new?
Posted: Sat Dec 26, 2015 10:35 pm
by alanscottj
When putting a spare engine together recently I managed to damage the crank by tapping the crank into place using a rubber mallet. Big lesson learned

anyway, when I put the mag housing in place the crank turns but then jams up
So, can I get it repaired? It's a Mec Eur crank and fairly new so it would be nice if I could salvage it

Re: Can a damaged crank be repaired or buy new?
Posted: Sat Dec 26, 2015 10:56 pm
by HxPaul
First of all,are you sure that the crank is damaged ? If the oil seal plate hasn't been fit perfectly square you can get these symptoms.If it were my engine I would strip it down and remove the crank and seal plate and check that the plate is seated square.
Re: Can a damaged crank be repaired or buy new?
Posted: Sat Dec 26, 2015 11:11 pm
by Chris in Margate
I think you might struggle to damage your crank by persuading it into place with a rubber mallet. As said take it out and inspect it and check the oil seal plate and drive side bearing; they are a highly likely cause of your problem.
Re: Can a damaged crank be repaired or buy new?
Posted: Sat Dec 26, 2015 11:14 pm
by alanscottj
I LOVE YOU GUYS!!!!
I have just taken the plate off and the crank spins freely with the mag housing in place! Before I removed the plate I had a close look and when I ran my finger around the edge I could feel that one side was ever so slightly higher than the other.
Thank you

Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 10:51 am
by Minority
Great result!, but I would still look at pulling the crank into place rather than helping it with a mallet.
Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 10:59 am
by Chris in Margate
I certainly would never advocate belting it with a mallet but I have always gently tapped and rotated as I inserted and then pulled it in.
Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 11:08 am
by hendy
I had a similar problem caused by a too-thick halite gasket pushing the plate against the crank web. I resolved by using a new gasket from mb developments which are only 0.7mm thick.
It could also be that your crank is slightly wider than original. If so you can get mag housing gaskets up to 1.5mm thick from mb developments.
I don't work for mb developments

Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 11:44 am
by HxPaul
hendy wrote:I had a similar problem caused by a too-thick halite gasket pushing the plate against the crank web. I resolved by using a new gasket from mb developments which are only 0.7mm thick.
It could also be that your crank is slightly wider than original. If so you can get mag housing gaskets up to 1.5mm thick from mb developments.
I don't work for mb developments

MEC halite gaskets are bad for this,they seem to be a lot thicker than the cheaper Indian ones.
Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 7:03 pm
by alanscottj
Cheers troops, lesson learned! I notice in Sticky's he writes in bold 'do not hammer'

Managed to get crank in and mag housing and front sprocket all fitted today and it all looks good.
Every day's a school day

Re: Can a damaged crank be repaired or buy new?
Posted: Sun Dec 27, 2015 8:02 pm
by Lamaddict
Or use a pin punch at the end of the crank. I love hearing the noise change when the crank is fully home, clunk, clunk, click.