CMB 90 Crank Rremoval

[Mick J]

Hi all, just wondering the best way to remove the crank on a CMB 90. Never done this engine before and as such wondering how to remove the crank so I can change the piston and rod :blink: . Not too sure on this whole pinned crank thing, got me beat

Aany help appreciated

Johno

 

[AWaddle322]

Johno,

You have to remove the wrist pin circlip thru the exhaust port. Wrist pin is threaded to 8/32 best i rember. get a screw, thread into wrist pin, take pliers and pull on screw, this will remove wrist pin. This is all thru the exhaust port. This will get your piston loose. With the flywheel plate removed you can turn the crank in one certai motion and it will come out. The rod is pressed inbetween the crank halfes. You really need to send this to tidewater or someone like as the alignment of thses crank halfes is very important. Putting it back together is even more fun.

Allen

 

[TimD]

Johno,

Gary Holborow in Sydney has all the gear to do the CMB cranks. Contact me via PM if you need his details - 1st rate guy to deal with.

Being from Aus it might be easier for him than Tidewater.

Tim.

 

[Mick J]

Thanks heaps for the info guys. I'm going away at the end of the week (back to sea again), so I'll hang off on it until I get home mid Sept. Thanks for your suggestions, they are appreeciated and Tim, I'll get those details off you upon my return.

Thanks again for the prompt responses

Johno

 

[Mike Broad]

I don't know if you get the magazine where you are but last month's Model Boats issue had detailed instructions complete with photos showing how to strip the CMB 90.

Mike Broad