Topic: M3 tensioner installation

[Silverback]

I am assembling a motor with the M3 tensioner, which did not come with instructions. Looking for help from someone that might have istalled this or had the instructions included with the tensioner.

The pivot pin at the bottom of the tensioner is an extremely tight fit. Should I open up the holes so that the tensioner actually pivots around the pin, or should it just rock back and forth on the rubber inserts at either end of the pin? If I leave it tight, is seems as though any misalignment during the installation procedure would be maintained due to the extremely low tolerance (It takes quite a bit of force to get the pin in), resulting in the cam chain rubbing on the inside of the tensioner, and possibly not sitting in the groove correctly. Also, it seems as though I should install the spacer that is used in the stock configuration. I know the tabs would need to be ground off, but the spacer is still too wide to fit. Is this something that should be left out, or should I throw it on the lathe, and trim to fit? I'm sure that the tensioner will hold up, but I'm surprised about the quality of the machining and rivets. Just seems a bit hacked to me. 

Thanks

[H2Eric]

The M3 instructions are;
1. Remove Honda OEM bottom and tension rollers, use only the pin to locate the M3 tensioner.
2. On CB350 Honda twins you must be sure that the tensioner pivots easily front to rear when cylinder head is installed. Note: Most 350's need to have material removed in the cam chain gallery.
3. Use OEM Honda tensioner at rear of cylinder to tension. Let the spring do the tensioning. DO NOT apply more than spring tension to the tension bar.
4. Good idea to always install a new cam chain when the engine is apart. Note: You must use a cam chain with full side plates, not 'peanut shaped side plate cam chain. Available from M3, Dynoman, etc

Having very recently installed an M3 tensioner make sure that the tensioner moves easily on the pivot pin, but without any excessive play. Make sure the pin is in good condition without any groves.  Pivot pins are no longer available from Honda so you may have to get one made as I did - Phil Denton Engineering.
The chain will sit nicely in the centre of the tensioner without touching the metal sides.
May I also say M3 tensioners are great. OK KOS that will cost you a discount the next time I order anything from you

All the best
Eric

[kos]

Thanks to Eric for his spelling out the M3 Racing tensioner instructions. I always send them with tensioner but I must have missed this one.  Yes, Eric... a discount is in order.

Mark @ M3

[Silverback]

Thanks! Did a little work on the pin retaining holes to make everything smooth. Moving on!