1100 Sporti Crankshaft Problem

I have just had my bike in to the local MG workshop to sort out a leaking Main Rear Seal, unfortunately it transpires that the chrome on the end of the Crankshaft has come off - damaging the seal. The dealer is not sure what to do, so I am going to post this on the MGCGB Forum and see what advice comes up.

Apparently my two options are :

  1. Buy a new Crank - difficult to find and very expensive.

  2. Have the end of the Crank re-chromed - need to check if this is technically possible.

Any advice and suggestions would be most welcome.

You can see a photo of where the problem is on : plus.google.com/photos/100879935686021516955/albums/5840978339713058417/5977327079529150770?banner=pwa&pid=5977327079529150770&oid=100879935686021516955Carbonari2014-02-07 17:19:10

so sorry to hear this ,I had big end bearings go on mine and I know the worry the crank can cause you .
Got me fingers crossed for you

Thank you

new crank i expect

problem with re chroming is you will probably need to have it ground down to the correct size as you have no guarantee that the chrome plate would land exactly the correct thickness.

might be worth talking to NBS

Will do

it can sometimes be cheaper to get a short engine from somewhere like gutsibits or reboot and scrap the bottom end of your engine

Bl**dy nuisance that Aldo -hope you get it sorted without too much fuss and cost…

For sure Dan, I am sure someone on the forum will point me in the right direction - I am sure it is going to cost, but I LOVE this bike!

Yes I think the Sport 1100 is one of the big underated Guzzi’s, but then we are biased, aren’t we Just got a new front tyre for mine in anticipation of the spring (well you have to be an optimist don’t you!)

II agree, was just about to put some new rubber on mine - will have to wait. Might have to buy a second bike and keep the Sporti for fun


I have to admit, I had not realised there was any chrome on the crankshaft.Would it not be possible to grind it down and reprofile as you do with camshafts?

Can’t access the link on me fone. Is the flaky area corresponding with where the seal passes over and runs Aldo…
Further to that, how bad was the leak, few spots or clutch slippingly persisting out…guykate2014-02-08 09:57:03

The oil leak out of the side of the engine was quite significant, I am told by the mechanic that the flaking was where the seal passes over - unfortunately they did not take a photo. Jim Blomley is now looking in to this for me, hopefully he will be able to fix it. Thanks for your input

Hi Brian, I am not technically knowledgeable to know if the crank is chromed - thanks for your input

Can you not get it ground down and metal sprayed?

I know you can get the chrome built up on fork legs without doing the full fork, filling pits, that are to deep to grind out!

Or just smooth off, so it doesn’t damage the seal?ianboydsnr2014-02-08 11:09:20

Well Jim knows his guzzis, glad you sortin it…

Guys take on this is that they are nitrided, ground and polished not chromed…interesting…
sometimes, believe it or not, the rubber seems to wear a ridge or at least in our experience…
One wonders if the damage would respond to a lite dressing…

I have used SRM engineering in the past for crankshaft work they do grinding and nitriding they mainly deal with British bikes but should not be a problem for them
Keith8 Valve Eagle2014-02-08 12:56:31

Should not be a problem to repair
not sure on the how the crank looks but if parrell shaft I would suggest as we do on water pumps have it skimmed slightly under size and have a hardened sleeve made and shrink fit it on the crank it will never move in its life