Whilst doing a trial last Sunday in the Lakes, I was heading to the last section on the first round, heading up some steep wet grass in 3rd gear, the bike was pulling fine and I could see the start of the 9th section.
All of a sudden I felt the bike 'go' and the engine rev like a beggar. I had no power to pull up anything and ended up jumping off as I over balanced and the bike nearly went over.
A bit perplexed, I kick started the bike, it wouldn't hook any gears and was trying to pull away even with the clutch in, so it stalled. I eventually managed to get it back into neutral, kick started it again and managed to get 1st, but every time I revved the engine, the bike slowed and the engine revved higher...
I did the section in first, which was an easy rocky section luckily but as I exited up the steep bank, it lost power on the climb just after the gate (thankfully) and cut out. ironically this was the only clean section I did all day!!!
Once I got it restarted I found I couldn't rev the bike past a certain point, so as it was a long & slow ride back to the start where the van was parked. I steadily crept my way back over the hillside with Lucy in tow as this was her first trial.
We stopped for her to have a go at the first 3 sections again and then I set off back to the van, having to push the bike up the slightest of inclines as there was just no power past a certain point on the clutch.
Once back home, I cleaned the bikes and the next day started to strip the Sherco down. Sherco USA produces a great service document for this job, so I simply followed their instructions...
1. Drain the oil - get it all out so leave it for half an hour to drain properly.
2. Remove the clutch casing. (4 x 4mm allen nuts) & the rear brake pedal - (13mm ring spanner)
3. Number the clutch spring bolts & mark the plate so you know where it all goes back
4. Remove the clutch spring bolts and and plates evenly - (8mm socket) & the clutch basket, (24mm socket), be careful with the washers and roller bearings, maybe even photograph the layout as they come out.
5. Inspect the lot, replace as needed - These were just a tad worn and broken! I also checked the bearings, sprocket teeth, clutch springs, washers and seals to be sure.
6. Order the parts, then wait for delivery!
And then once you get them...
7. Soak the clutch plates in oil for at least 15 mins, to let the friction material soak up some oil.
8. Mount them carefully starting with a friction plate first & last.
9. Rebuild the basket, being careful not to lose any of the bearings/washers.
10. Replace the clucth basket back into the engine, (the central nut is tightened to 60Nm & a washer goes behind it) and tighten up the clutch spring bolts to 7Nm
11. Test the clutch action before installing the clutch cover, it should release smoothly and evenly.
12. Replace the clutch cover and its 4 bolts, check the rubber O ring for damage etc.
13. Refill the transmission with oil. SAE 75w light gear oil x 450ml
I got the clutch plates from
OffRoadMoto on EBAY for £83.45 including postage for a full set. There are 5 metal plates and 6 friction plates. You can also buy just the replacement plates from the Splat Shop
HERE but as I have no idea how old the ones in this bike are I preferred to replace the entire set.
Some specs below:
Clutch Hub Nut - 60Nm
6 Clutch Springs 7Nm
450 ml of SAE 75w light gear oil
Minus the post time, the whole job took around 2 hours. Most of that was because I also cleaned and checked a lot of other bits.
Clutch leaking/not working well...
Since replacing the clutch plates, I've had a mare to get the clutch to work well... it was beautiful at first, really responsive and the bike was lovely to ride. Now it runs for abour 10 - 20 minutes and then I have no clutch or a really sloppy one. I've bled it several times now and each time there is a different level of fluid left in the master cylinder, so I think it's drawing in air somewhere and/or leaking fluid.
After about the 10th time of bleeding the clutch, I clamped the piston in on the removed slave cylinder with a small G clamp and compressed the clutch lever on the bars with a full cylinder of fluid. By rights this should create the maximum pressure in the system and show up any leaks.
The only fluid I can see with all this pressure is at the slave cylinder end, the piston is covered in Dot 4 fluid. So I've ordered a new slave cylinder from the Splat Shop, with postage it's £55. This clutch has had a replacement slave cylinder before I thought, but I can't find a record of it so I'll change it now and be sure. Once this is done, it's had everything replaced except the master cylinder body now, so time will tell!
25/12/2016
The new slave cylinder made such a diiference. it's the best the bike has ever been since I've had it... again it was a beggar to bleed through, with the new piston sticking shut and requiring a blow of compressed air through it to free it off, but once it was out, I lubed it up with some clutch fluid and refit the piston gently. After taking a long time to get the air out of the system, the clutch is now beautiful, light, responsive and the front wheel lofts lovely over obstacles... great stuff!
So it was off to the Boxing day trial with Lucy, albeit with a slight bout of dehydration from a little too much wine on Christmas evening!
