Hardcore Biker
sounds like its time for some basic checks... give it a teaspoon and-a-bit of fuel down the plug hole and see if it trys to run for a few seconds.( you might need to kick it 5 or 6 times with a handful of throttle) if so, you've narrowed the problem down
L-Plate Rider
HAHA.. I knew I didn't explain it right but I'm glad someone understood what I meant.Originally Posted by F5 Dave
L-Plate Rider
Update....
finally gave in and took the bike to the shop.
They found the Keyway for the flywheel had broken. This let the flywheel move which messed up the timing.
I never would have found that, even when I checked the flywheel and it seemed ok.
Anyway, its going now
Thanks for the help everyone
No8 Wire Extraordinaire
Cool. Chocolate fish to Kickaha for guessing correctly.
Pants to Luigi for not tightening it up at the factory properly.
Don't you look at my accountant.
He's the only one I've got.
Forum whore
Point of order -the key sheared - the keyway is the slot the key goes in. If the key is semi circular then it is a woodruff key
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
In the riders seat
The bikes I have seen do it were obvious once the side cover was removed though
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."
No8 Wire Extraordinaire
It will be a woodruff key, yes.
It is only there for easy exact assembly of course. The taper locks it in place. I've assembled racebikes without keys out of necessity, but it is a pain so I've got the flywheel broached in correct location and filled the old one once settled.
Don't you look at my accountant.
He's the only one I've got.
Forum whore
My F9 Bighorn used to shear keys regularly, until i lapped the rotor to the taper with fine valve grinding paste.
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
Low personal B.M.E.P.
Surprising how many people use woodruff keys that are too tall. The flywheel ends up running on a small piece of shaft and the top of the key
Doesn't last long.
Saw just that at one Lady Wigram meeting. Freeth was running the Starlet and had sheared a rear hub key. Sprint car quickchange solid axle.
So naturally he comes into the bike pits and asks who's got a box of woodruff keys with them ?
Jungle McGregor was standing there so I immediately said - You know Jungle don't you Roger, he just lives literally round the corner - and i'm sure he'll have everything you need. Away they went to Jungle's place.
Talked to Jungle later and he told me they'd lapped both hubs and put the correct keys in. Both had been too tall for the keyways. DNF just waiting to happen.
No8 Wire Extraordinaire
Ahh can see how that happens. It won't wobble because it's centred by the washer and nut.
Thanks will look out for that. They usually only go 1/2 way up groove but that makes sense now.
I have a small selection in my race/dirt toolbox.
I've used fine valve grinding paste (also in toolbox) to clean up suspect tapers. Obviously it's never been used on valves. They live in inferior engines.
Don't you look at my accountant.
He's the only one I've got.
In the riders seat
I sheared one in first practice on my IT200 at a VMX, I didn't even try and find another one, lined the flywheel up on the shaft, tightened it with an impact gun and finished another 5 races
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."
Easy Biker
Kick it seemed to me back in the day it was a 2T problem because I never saw a 4T Honda have a flywheel move. Is there an explanation as to why the 2Ts do this?
Cheers
Merv
No8 Wire Extraordinaire
Probably a combination of heavier flywheel (foulstrokes hide their inertia in associated reciprocating components) and
home mechanics doing rebuilds on the more simple 2 stroke bottom end, but having nothing to properly hold the round flywheel, much less own a torque wrench.
Our friend here suffered from Giuseppe being distracted by the delectable office girl and then rushing off for a lunch of. . Actually, I have literally just finished last night's leftover spaghetti and Italian meatballs so I've fallen into my own stereotypical trap set to slur anyone else but my culture.
Oh the shame.
But if it happens again (unlikely) I'd be reaching for the bearing blue to test the taper has wide engagement, then the valve grinding paste.
Machinery tools lathes etc rely on tapers and are quite reliable.
Don't you look at my accountant.
He's the only one I've got.
Hardcore Biker
Just a fine point on lapping flywheels on to tapers - when you've finished lapping you need to relieve the ends of the flywheel bore a few thou to allow for the fact that with the paste cleaned off the flywheel will advance up the taper further. if something like a gp bike i will have it's rotor heated in hot water before fitting to give a secure "bite". peace of mind ...
Low personal B.M.E.P.
I don't think Kick's old enough to know this one.
2T's have a lot less advance than 4T's. It is quite possible to wind up with a cylinder full of hottish gas ready to light and have it fire at low enough RPM that the flywheel mass does not carry it past TDC. It then kicks backward. This can of course loosen the flywheel nut which leads to the already seen sheared key.
4t's don't generally do this because they have well defined intake, compression and ignition phases.
Back in the day when 2T oils were depositing thick crusts of crap on anything they came into contact with it wasn't unknown for this hot crap in the ports to fire any mixture whic came in contact with it. One instance the old man used to quote was a mate riding a Scott. Held up by traffic at one of ChCh's bridges and stalled.
Let it run backwards to give himself some room, let the clutch out to slow down - and it fired - and ran backwards. Till he fell off.
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