Cuts out when hot

[hallie]

Recently my bike gas started to run like crap when it gets hot. Cuts out and is hard to start again.
Also there's a bit of a whine from the engine which rises and falls with the revs. (Not a great explanation) I know
Any ideas where to start looking

[MacV2]

Recently my bike gas started to run like crap when it gets hot. Cuts out and is hard to start again.
Also there's a bit of a whine from the engine which rises and falls with the revs. (Not a great explanation) I know
Any ideas where to start looking

Check your petcock diaphragm...Tiny litle pin hole or a rip at the edge can have simular effect...Easy to do...Vanstub has simular issues...changed coils, ecu ect...lots of stripping & swapping of parts to no effect...The diaphragm had a rip in along the edge...Fitted a new one problem solved.

[moto1818]

Is the bike perfectly ok when it is cold?

Does the bike misfire at all or just cuts out when left to idle and is hard to start?

Sounds like over fuelling with the very limited information given, possible choke issue/sticking?

Try to give us more to work with like exactly what your feeling when it runs like crap is its bogging down, misfiring, lacking power etc.

Are you able to do any basic fault finding tasks to help us find the solution? Stuff like checking plugs, coil voltages and resistance checks?

Cheers,

Bill.

[hallie]

Is the bike perfectly ok when it is cold?

Does the bike misfire at all or just cuts out when left to idle and is hard to start?

Sounds like over fuelling with the very limited information given, possible choke issue/sticking?

Try to give us more to work with like exactly what your feeling when it runs like crap is its bogging down, misfiring, lacking power etc.

Are you able to do any basic fault finding tasks to help us find the solution? Stuff like checking plugs, coil voltages and resistance checks?

Cheers,

Bill.

Starts and runs fine when cold. Problems only occur when it's hot (temp gauge around half way mark). Plugs coils all ok. Mac may hit the nail. As when it's hot it's like it's being starved fuel.... splutters alot and dies. Then it's trying hard to turn over to get it started again

[moto1818]

I don't see the temperature having any bearing on the fuel diaphragm, it should be the same hot or cold if that was the problem??

It's a very simple check in any case to see if that's the issue. I would also be looking at an air leak on the inlet side of things, possible carb rubbers, that could give warm running issues, hope you find it!!

[MacV2]

I don't see the temperature having any bearing on the fuel diaphragm, it should be the same hot or cold if that was the problem??

It's a very simple check in any case to see if that's the issue. I would also be looking at an air leak on the inlet side of things, possible carb rubbers, that could give warm running issues, hope you find it!!

At higher speds, revs, load...The Vacuum is pulling harder which stretches the diaphragm more...

Vanstubs bike was doing excatly that...fine starting from cold & running but a M/way speeds it was cutting out...

[moto1818]

OK, I now see a possible link! I guess the test would be to let it idle until hot and see if it still does it?

These types of problems can be a beggar to find but ace when you get it!!

I don't see the temperature having any bearing on the fuel diaphragm, it should be the same hot or cold if that was the problem??

It's a very simple check in any case to see if that's the issue. I would also be looking at an air leak on the inlet side of things, possible carb rubbers, that could give warm running issues, hope you find it!!

At higher speds, revs, load...The Vacuum is pulling harder which stretches the diaphragm more...

Vanstubs bike was doing excatly that...fine starting from cold & running but a M/way speeds it was cutting out...

[hallie]

Cheers Mac. Will check that when I get back to the bike. Away with the annoying people (family) for the long weekend

[hallie]

Petcock stripped and checked and all seems ok so none the wiser now

[tony.mon]

Had you changed to manuals?
Could be they're too tight.
I'm thinking about the whining noise you mentioned.
Peacock won't make a noise anyway.

[hallie]

Have stopper mod done
Clearence were done 5k ago

[VTR Phoenix]

Get the bike hot and then turn it off, attach a dmm to the battery and start it, see what the drop is, a battery on its way out will show same symptoms. Also check what the charging is when running.

[hallie]

Get the bike hot and then turn it off, attach a dmm to the battery and start it, see what the drop is, a battery on its way out will show same symptoms. Also check what the charging is when running.

12.3 not running drops to 10.8 on start up and when running its reading 13.5v. Seems about right to me.
Thinking valve clearence next?????

[VTR Phoenix]

Is that when the bike is hot?

[hallie]

Is that when the bike is hot?

Yeah