MOT comments

[allen m]

Hi all
My 125 Evo have just passed the MOT with a couple of comments.
1 - Very slight leak from the joint between pipe & silencer. I had replaced the old seal with a new graphite ring and clamp.
However, despite cleaning all the old crud of the pipe & silencer it was a pain to fit and broke up a bit at the end, thus the leak. What is the secret of fitting as I have never seen a joint like it before.

2 - The steering is a bit stiff. The tester is pretty sure it is the stiff braided brake hoses as it is not rough but recommended lubricating the bearings just in case the are drying out.
Is this very difficult to do, please?

Your comments appreciated to a new scooter rider after 55 years of bikes.

Regards
Allen Morgan

[shedload]

Stiff steering is usually a sign of bearings issues. My Evo failed on stiff steering and when I went to loosen off the steering head the bearings collapsed!

[Dave Milnes]

To fit a new graphite seal you need to be absolutely sure you have removed all signs of the old one, especially in the swaged section of the silencer input right back past the expansion slots.
If you can slightly expand the tube inserting a slightly smaller diameter tube and 'stirring' it round flaring the pipe slightly, then smear a little coppaslip around inside to help the gasket slide in. Press the gasket into place using drift such as a socket. Tap very gently until it sits past the end of the slots then roll the leading inner edge into a slight chamfer so the front pipe slides in without damaging the seal.
Put a really loose fitted well oiled clamp down by the silencer first then when the silencer is loosely bolted up, tap it along the pipe so it squeezes the pipe back down then nip it up about 5mm from the end of the outer pipe but don't heave it tight as you will simply crush the gasket then need another one on next removal. They can be progressively 'crushed' so lasting three or four removals before renewal.

Check that the cables aren't excessively tightly clipped to the headstock. They need to be well supported but still free to move slightly and not bunched with the wiring loom where they pass up through the bottom collar under the handlebar clamp. Don't clip them inside the handlebar covers either, leave them free to move. To grease the bearings you need to lift off the bars and this bottom collar then loosen the two locking rings then lower the yoke a few inches so the lower bearing is visible then clean it and re-grease. The upper bearing will simply lift out.
Re-nip the lower collar so there is no play in the forks, then give it another eighth of a turn tighter before tightening the upper collar. Use a drift and hammer carefully.
Refit the bottom collar then handlebars and tighten the clamp when you have aligned the bars.

[allen m]

Hi Dave
Thanks for the info.
The exhaust. I did clean the joints inside and out but did not use copperslip. Should have known, I had to use it on the BMW cylinder head/exhaust connection! I will have another go with a new seal.

As to the steering, as I mentioned the tester considered it might be stiff braded brake pipes. What I will do is undo the clamps on the forks as they are reasonably easy to reach and see what happens. If there is any doubt I will grease the bearings.
As it is safe to ride and I do very little, maybe none in the winter, I will leave these items (and the battery & charge covered by another post) until the days get a bit longer, probably March.
Though different to anything before I now enjoy it but not if cold, wet and slippery, my body or nerves can't take it.
Thanks again
Regards
Allen Morgan

[allen m]

Hi all
At last I have had another go at the leaking exhaust joint.
From the replies I found that the graphite ring had not gone in far enough and it had become damaged. I cleaned out more old crud by using a small flap wheel in the electric drill. This then showed that the pipe end was distorted so some careful bending with narrow/long jawed grips got it nearly right. Carefully assembled everything using a new ring & copper slip and tightened the clamp (a proper wrap round type with a pull-up bolt). However there was still a very slight, though much reduced leak so I pressed a bit of exhaust sealing compound into all the small gaps around the joint.
To by mind the joint is badly engineered. On all the motorbikes with sleeve joints I have ever had the pipe goes into the silencer. This way the joint only has to seal any back pressure not the whole direct force of the hot gases.
Anyway, thanks for all the advice.
Regards
Allen Morgan