lotus54

I finally figured it out. Bozo brain. Yes, it would have worked a lot better if the ‘arms’ came out further. There is certainly travel on the slave and room. The clutch fixer shaft was broken on mine (this is the type that does not normally come out) so I didn’t have anything to model it from. I just estimated length. I did try to measure from hub in to make sure clutch slave would not hit it, and I thought there was room. For some reason, I didn’t think of just putting some engineers blue and fitting it. Well, finally I did and found it WAS hitting. So I trimmed the shaft down to the bolt head. Now it works fine. What a dope! I figured it may help someone else.

I measured a new pack and it is about the same- plus that one worked fine in original gearbox. So I suspect the very late gearbox it originally had used a slightly different pressure plate. Mine measures 7mm thick- it would be interesting to see what earlier ones measure. I could make up some slightly thicker release arms, but that does not really address the root issue at all. Now the arms only are about 8.3mm away from the clutch hub, not enough (I was reading your measurments and about half). So I’m sure what is happening is the clutch slave pushes the arms in just fine- but then bottoms on clutch hub and will not fully release. I am 3D printing some slightly thicker arms- just for testing. But I think I will likely need a different pressure plate. Xiu has a ventilated one, but no longer avaliable. I’m in no huge hurry right now, I have loads of other projects to finish and it has been a bit cold for me to ride.

I had not seen this one you did. Good info. I just measured best I could from the ‘mounting pins’ and bottom plate and the clutch outer hub to plate. The pins down are more difficult to measure accurately, since there is a ridge between plate and base of pin. I will do some more measuring- fitting the clutch pack into the other gearbox and see what I get. I am almost certain the replacement gearbox is a older one than the one that came out- since this is likely one of the last bikes made. F thanks for the help.

late 2015 Explorer. Clutch worked fine. Gearbox had chewed up kickstart idle gear, so Lewisport swapped out for a good one. (Same size mainshaft bearing). Fits fine of course, but now it is like the clutch pack is too thick. (9.88mm). I have another gearbox here (not the one that came out) and I measure darn close between ‘bottom’ plate and hub/inner hub. But the ‘fingers’ do not stick out enough from the hub- so when the slave is activated it pushed in fine- until it hits the hub. Lever only moves about halfway. Ideas?

OK, I forgot that. There is no play in the 20 mm pin (which is smaller now, since it has needle bearings, but much stronger material)

Those are the places to check (and upper damper). Can you see where the play is? This does have very good tolerances. .0005”

I’ve always used the only oil the importer in the States told me to use. Maxima Extra 4 0-10W full synthetic. It has always worked very well for me. Since it sounds like it used to work, but has gotten worse, of course bleed clutch. But I suggest also changing gearbox oil- making sure to drain it all (on later bikes bottom screw allows clutch side to drain, otherwise loosen all a bit and move cover out slightly). Then fill with 450cc of oil. It will be well over the sign glass. That was made back when it only used 350cc, but OSSA found that the Italians were running 450 and not having any issues, while others using spec were. So I use that in all models (with appropriate hose routing). Clutch plates perhaps could use a ‘deglazing’ but I would try other things first.

No play in this setup. But certainly if any pins/bushings/bolts worn it will have play. I would have liked to use needle bearings for front pivot, but doesn’t look like enough room. But the most stressed one is the middle one (I think) and that is now needle bearings. Also check the bottom damper bushing

I have the slightly modified version installed. I very slightly changed some tolerances (the place making them follows better than I expected). And had to change the ‘dogbone’ to similar thickness to stock, although a bit taller. (Would not clear Olins). I really like the almost flush grease fittings. They work really well and easier to access. Just require a very inexpensive adapter. Works great!

I’ve never had them leak, but of course things are getting older. You could always use a ‘regular’ clamp- I like the ‘euro style’ ones. Like these (but the Norma ones are about the best) https://www.amazon.com/gp/product/B0040CVQJ8/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

Original is steel w/teflon coating. This has the same except middle ‘main’pin that is now needle bearing. When I have final fitting done I will let you know. I have to make another bit of a change to clear Ohlins damper- the Ollé is smaller diameter. But that is what initial testing is all about.

Yes, Explorer and TR are the same. The grease fittings are there- I used flush ones that use a ‘needle’ type end. Three of them could have ‘regular’ zerk fittings, but the one for the main pin does not really have enough room. Before I sell any, I want to make sure everything is just right. I have made some little mods. I wanted to keep as thick as possible for strength, but also need to have clearance for the Ohlins or the Olle dampers since the springs are a bit different in size.

Side by side with factory, and mounted in swingarm. Dogbones are 10mm thick and original is 7mm. Plus made from Ti grade 5 vrs some sort of aluminium for stock.

No, it should have very linear power. The 300 factory has a LOT of power as you run it up, but a regular 280 should be really nice ll along. I would suspect the TPS, but of course all the components work together. I suggest doing a compression test (throttle wide open, kick until gauge stops) and make sure it is good. Then get the cable (I can send software if you don’t have it anymore) and set everything up properly.

I made only very minor changes and they would not be apparent at all in pictures. Like .001” dimension change