Front forks stripdown and refurbishment

[ringer]

Suspect that my LH front fork seal is going to go sometime soon. The dust cap is cracked and I think I see evidence of fork oil smeared on the part of the fork above the seal (sorry, don't know the correct term).
How difficult is it / what's involved in sorting this out? Special tools needed? What parts should I order? Is it worth replacing headstock bearings etc if forks are off and stripped?

[EVguru]

Suspect that my LH front fork seal is going to go sometime soon. The dust cap is cracked and I think I see evidence of fork oil smeared on the part of the fork above the seal (sorry, don't know the correct term).

It's called the fork stanchion, leg, or tube.

When I bought my 350 Sport about five years ago, the one thing the previous owner told me I'd need to fix was the fork seals. I've still not done them! Once I started using the bike regularly, they stopped leaking.

A little oil is not a great cause for alarm. It's not an MOT fail unless it starts dribbling down the side. It's worth seeing what the problem might be though.

Take the weight off the front end so the foks are extended and lift the dust boots up. You're looking for pits, gouges and areas of worn or missing chrome. Small blemishes can be stoned out and it's even possible to use epoxy as a filler, althought it's only a stopgap. If there's nothing obvious try draining the fork oil. If it comes out as a grey or brown sludge, then you'd probably best strip the forks.

How difficult is it / what's involved in sorting this out? Special tools needed? What parts should I order? Is it worth replacing headstock bearings etc if forks are off and stripped?

It's not difficult unless the damper rod bolt has been locktighted into the damper rod. You then need to tap a tapered rod into the top of the damper rod to stop it turning.

http://www.ducatimeccanica.com/marzocch ... /index.htm

I'd fit a new set of balls in the races, at about 2p each it's silly not to!

I use dowty seals under the head of the damper rod bolt, much more reliable.



I think NLM do them.

Other than that, it's just fork seals, dust caps and fork oil.

Ask two Morini riders about fork oil grades and you'll get three answers. Morini seem to have used several different sets of fork internals and they need different oil viscocities. The HLP80 mentioned in the 'Blue Book' service manual is hydraulic oil (ala JCB) and is equivilent to 30W fork oil. With some forks that would make them nearly solid and some owners are down to 5W oil. I'm running 20W in my 350. See what feels 'right' for you.

[ringer]

Thanks for the comprehensive reply Paul. Will put it on the list of 'things to do sometime in the future'. In the meantime, it gives me an excuse to ride up to Ellistown to buy the parts.