New clutch trouble

[turbokh]

I installed new clutch disks and plates in a dirt squirt. I have all the necessary play taken out of the cable, but when I pull the clutch lever the bike doesn't roll free when in gear. should I have soaked the new fiber disks in oil before assembly? never ran into this before.

[Zyx]

It will only roll free in neutral. Wet clutches drag, especially vintage design, dirt bike wet clutches. Keep in mind that nearly all Hodakas do not have primary kick start, and as you know, the clutch is on the crankshaft. Whatever gear you are in, that overall gear ratio is being used to drive the crank pinion and half the clutch pack when pushing engine off. That is a huge mechanical disadvantage. In first, it is usually 1:43 or so. Forty three revolutions of the crank pinion for every turn of the rear wheel. No, it does not exactly roll free. The real question is whether it works.

If you absolutely have to push the bike in gear, pick third and up.

[Pep]

Yes on soaking, but you might could get past that anyway with a little riding.
Check your free play at the hand lever, and more importantly, at the engine case. If all that is good, warm up the bike, work the clutch, (lots of tips on that in this forum).
And enjoy the "fun hundred"!

[Zyx]

As far as I can tell from measuring new friction discs and ones that have seen oil, the disc material doesn't swell appreciably, so they don't really soak up oil. If they did, they would become less likely to roll free than when dry because they would be thicker. The oil bath doesn't lubricate the discs and make them run freer. Instead, the oil film between the discs when the clutch is pulled acts like a torque converter in an automatic transmission. The friction discs tend to drive oil because of their tread face, if you will, so they are contstantly pushing a load of oil ahead of them when being pushed by the rear wheel and transmission. That creates drag. In first gear you can really feel it. Assuming you can push it at all clutch in engine off in first, you will hear the whine coming from the clutch and gears.

Try pushing it in fifth and see if it rolls more freely. Unless it is not free at all and drives the piston through a stroke when trying to push the bike in fifth, you will notice a vast difference pushing around 1:1 ratio instead of 1:43 as in first.

Anyway, freewheel in gear isn't any kind of a pass fail test for a clutch. Start it, drive it, then decide if it is working correctly. If you can start in neutral, pull the clutch, and select first gear without stalling or running down the driveway, it is working about as free as it is going to get. If there is no release even with full lever deflection, something else is going on. Try it and let us know what the result is.

[turbokh]

I understand disc friction, and certainly cable free play. It doesn't roll free in any gear. I'm concerned that there's something wrong in my installation of the clutch. I'll just keep playing with it. Thank you.

[Zyx]

If it won't roll free in any gear, and in fifth, for example, with the clutch pulled it turns the engine over, something is missing from the discussion. For example, if you left out the clutch thrust button, you won't get clutch action at all. If the shims under the thrust roller are missing or wrong, you would get very little thrust at full pull.

Lay the bike on the shift side to drain oil away from the clutch cover, and remove the cover. Tie back the kick start lever so it is out of the way. Look for the thrust button which will probably be somewhere laying loose. If everything looks normal, shims are present and roughly correct according to your recollection of what was there to begin with, use grease to hold the thrust button in the cover when installing the cover or it will just drop out again. Reinstall the cover and with the clutch cable off, check for free play. The clutch actuating lever should be almost all the way down. The spec for free play is in the manual, but I think it is at or less than 3/8". If you have to move the lever more than that to take up slack, the shims are wrong.

Sounds to me as if you may have inadvertently let the thrust button drop free on installation. All this can be easily checked without taking the engine out. If you prefer, you can drain the oil and work upright, but it can be done without draining the oil by laying it down flat on the left side. Shouldn't take more than 15 minutes to see what is up inside the cover.

[turbokh]

I swear the thrust button was in the cover when I assembled it.. but it's a slippery little thing. I'll drain it and pull the cover. It's got to be something stupid like that.