running on one

[Spanner Man]

Good evening.


Bit of a nightmare indeed.

Have you blown through the vacuum tube to make sure there's no blockage at the engines end? Also make sure the other vacuum take off on the throttle body has got it's rubber cap securely attached.


Cheers.

Originally Posted by Spanner Man

Good evening.


Bit of a nightmare indeed.

Have you blown through the vacuum tube to make sure there's no blockage at the engines end? Also make sure the other vacuum take off on the throttle body has got it's rubber cap securely attached.


Cheers.

Yes i can confirm, no blockage, New Bodies fitted also?

[Spanner Man]

Good morning.


The mystery deepens! I would try running the vacuum tube from the IAP sensor to the other cylinder, just to eliminate the remote possibility of it being a fault with the engine.
The sensor is governed by engine vacuum, & if it was low on the one cylinder, due to a leaking valve or similar then it could send the wrong signals to the ECU.


Cheers.

Originally Posted by Spanner Man

Good morning.


The mystery deepens! I would try running the vacuum tube from the IAP sensor to the other cylinder, just to eliminate the remote possibility of it being a fault with the engine.
The sensor is governed by engine vacuum, & if it was low on the one cylinder, due to a leaking valve or similar then it could send the wrong signals to the ECU.


Cheers.

Ran the vacuum pipe to rear cylinder, Just the same.

[Spanner Man]

Good morning.


I know that you've changed the throttle bodies, but if for some reason both pairs of throttle bodies were excessively out of balance it's possible though unlikely that you could get the symptoms you have. After all, an engine needs air.
The balancing screw is on the throttle linkage, on the right of the rear throttle body. It's the one that moves a lot when you open the throttle.

With the engine running, try turning the screw, but make careful note of which way you're turning it. Try turning it at least a turn in either direction, & see if anything happens.


Cheers.

Originally Posted by Spanner Man

Good morning.


I know that you've changed the throttle bodies, but if for some reason both pairs of throttle bodies were excessively out of balance it's possible though unlikely that you could get the symptoms you have. After all, an engine needs air.
The balancing screw is on the throttle linkage, on the right of the rear throttle body. It's the one that moves a lot when you open the throttle.

With the engine running, try turning the screw, but make careful note of which way you're turning it. Try turning it at least a turn in either direction, & see if anything happens.


Cheers.

would say safely they bodies are not out of Synch, as when she is on 2 cylinders she is running very sweet!

A little more insight into situation arose yesterday!

Spoke to Previous owner, and he said that bike ran 100% perfect, at the manx Grand Prix, Due to the fact he finished on the Podium, the front Cylinder head was removed, And after re fitting this is when this problem has arisen? could it be something Mechanical?

What is swaying me away from this idea, Is the fact he finished the season off, after the Manx with the IAP sensor disconnected, so bike still performed very well.......

[Spanner Man]

Good morning.


You would be surprised at how well some engines can sound when the balance is well out. It will cost you nothing, take 5 minutes & anything at this stage is worth a go.



Cheers.