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Hello,

Any ideas anyone how to ease this process, the interference fit is crazy tight. Removal took a long time requiring a Hydraulic 3 legged puller, some sophisticated releasing agents and copious amount of heat. So much force was needed that the cirlip rim got distorted. I have a new one to replace but it is as reluctant to go on as the old one was to come off and the manual glibly says "reposition if necessary for optimum valve timing".

Help? Steve Pegg

Wow, it sounds like you had a bit of fun there.
Your best bet is to give the helpful guys at North Leicester a call and I'm sure they have you sorted in no time

They do need to be an interference fit, the key should only be for location.

Rust has many more times the volume of the metal if forms from, so it can really jam things up. Heat needs to applied at a high rate so the pully expands, rather than the crank journal.

The puller washer needs to as thick as possible so it doesn't distort. If necessary, you can recess the centre for the circlip.

I'd see no problen in 'easing' the fit a little, you can always use some low strength engineering adhesive that can have it's bond broken with a little heat. Definitely go that route if you ever have a pulley thats's a slip fit. Any looser than that and you need to be looking at doing something about the fit (like a custom undersize bore pulley).

EVguru wrote:They do need to be an interference fit, the key should only be for location.
.

Keyways are there for a reason. They are the sheer pin of a shaft. Yes the majority of adhesion is to do with contact area but a key way needs to be a weak link to save major mechanical components.

Maybe I'm misreading something but the standard puller fits into the internal thread rathr than pulling on the outside rim of the pulley. It is often the puller design and suitability that increases the chance of success.

I purchased a puller from ebay and it worked a treat. Same as some scooters.

Rod

Morizzi wrote:

EVguru wrote:Maybe I'm misreading something

You're missing something.

10 minutes in the oven at 450*f and it should pop back on np

As for valve (cam) timing, you will need a degree wheel attached to the crank
, 10" of stiff wire
(For a pointer) and patience. Use the factory listed valve timings
for your camshaft, with the tappets adjusted to 1mm clearance.

The blue manual tells you how, except it's wrong, you need to turn the
Crank the other way (crank backwards X*)

Gentlemen,

Thank you for all the replies, a lot of emery paper and a different sprocket I "borrowed" off another rebuild has resulted in an acceptable interference fit at least to me. It will still need heat and I have taken on board it needs to be a really tight fit. Thanks also for the comments on the valve timing I think I am ok with that.

"One Motto is not enough" Steve