timing

[olkno9]

had to have engins stripped because of a sheered exhaust stud, all been built back up and set timing to manual, bike fired up but its getting very hot on the front exhaust, is this because timing not set accuratly . any tips much appreciated

[warby221]

By the sounds of it I’d say you have a leaking exhaust valve, letting fuel in to the exhaust were it’s burning causing the heat

There’s only ignition timing that can create extra heat being to far advanced
And that’s controlled by the position of the ignition pickups and is pretty well set as it comes off the end of the crank

Valve timing being out usually just makes the engine run like a bag of sh*t

Bit of a pain I know but try wiping the front header pipe off and pore some light oil in and see how long it takes to drain in to the engine
If the valves are sealing it takes a bit of time for them to empty
If its gone in a couple of seconds then there leaking

[tony.mon]

Bit of a pain I know but try wiping the front header pipe off and pore some light oil in and see how long it takes to drain in to the engine
If the valves are sealing it takes a bit of time for them to empty
If its gone in a couple of seconds then there leaking

Top tip, Warby, I'd have gone straight in and stripped the front cam box off and measured the clearances.
Your method shows whether you need to.

[olkno9]

thing is i never did anything to the valves or anything, the bike ran ok before so i just re oved the lot in one lump and didnt alter anything, which is why i wasnt thinking of it being anything down that avenue.

[tony.mon]

In which case, re-check valve timing on front cylinder (do both while you're in there) and make sure that the front carb is properly seated on the inlet stub. (running lean=hot)

Is it getting hot enough to disclour, or just burning off a bit of oil/grease that's on the front pipe?

[sirch345]

had to have engins stripped because of a sheered exhaust stud, all been built back up and set timing to manual, bike fired up but its getting very hot on the front exhaust, is this because timing not set accuratly . any tips much appreciated

thing is i never did anything to the valves or anything, the bike ran ok before so i just re oved the lot in one lump and didnt alter anything, which is why i wasnt thinking of it being anything down that avenue.

I hope you don't mind me saying this, but your two posts don't add up, they contradict one another Or that's how they read anyway. Perhaps you meant different

If you have re-set the valve timing as you say in your first post then I expect this is not set correctly. It's not just a matter of resetting the valve timing on the front cylinder alone (I'm assuming it was the front cylinder that the stud sheared from), you need to make sure the front cylinder is set in the correct cycle with the rear cylinder. Also the camshaft lobes need to be facing in the correct direction.

If you didn't re-set the valve timing yourself, but it was done at a garage then I would suggest taking it back for them to sort out, as they may have damaged the valve's. I agree with Warby, exhaust valves not seating properly would cause the engine to get hot.

This link here will give you an idea of how the valve timing needs to be set:
http://www.vtr1000.org/phpBB3/viewtopic.php?f=9&t=8326

Chris.

[olkno9]

all i set with the timong was to the marks on the crank, didnt take the valves or anything out, just put back as i had taken off, ive run it and it doesnt seem too bad now, maybe a lot of the smoke just off exhaust , does sem a little off with the timing though so might need moving a tooth on the cam chain

[sirch345]

all i set with the timong was to the marks on the crank, didnt take the valves or anything out, just put back as i had taken off, ive run it and it doesnt seem too bad now, maybe a lot of the smoke just off exhaust , does sem a little off with the timing though so might need moving a tooth on the cam chain

Going by that, also if it was running fine before having to remove everything that you did to remove the sheared stud, then I would say the valve timing should be correct. IMHO even if it is out one tooth that wouldn't be enough for it to get very hot,

Chris.

[olkno9]

guy at bike place in thorne told me to run it a bit as smoke might just be because it has been stood a bit , it was mainly coming off the exhaust so i did and it seems ok , but not runing right so im going to check if altering timing a tooth might make it better.

[tony.mon]

CAREFUL!
You'll probably get away with timing one tooth out and not have valves hitting piston, but I'd be very tempted to rebuild the engine and turn it over by hand a few times with Plasticene or Plastiguage on the piston crowns where the valve seats are, then strip again and measure the thickness.

Better that than new valves, or possibly engine.

If you really want to play with valve timing, there's cam sprockets available with slots so you can adjust, but these are not more than half a tooth either way normally.

Unless anyone in VTR-land has already done this and can advise?