Revving problem

[Chris sweets]

Good afternoon fellas
Bought a bike which I now know was from a dodgy dealer, started having issues with it after about a month
The issue is the reviving, when the bike is started it idles fine, when your on the throttle the revs can jump all over the place even when you are holding the throttle steady, there is some popping from the exhaust when this happens
Anyone got any ideas or know of any common faults this could be?
I have searched on the internet and I'm going to start it up in the dark tonight and check from any sparking/arching, I'm also going to spray a mistake over the engine when it's on file to see if the revs change if it's taking in water from somewhere
Any help is appreciated

[tastethefloor]

have u check the plugs?
is the fuel "fresh"?
valve timing is correct?
is the bike already fittd with manual cct?
do u know if the pevious owner did some mods inside the carbs?
good luck

[VTR Phoenix]

Could be carb air leak, check carb to engine boots are tight and clips done up and carbs are seated properly.

[Chris sweets]

I have no knowledge at all of bike mechanics and only slight basic knowledge of car mechanic
the fuel is fresh and is BP
No idea what a cct is
And I thought the valve timing couldn't be adjusted
As far as I know there has been no mods to the carbs but it has got road legal scorpion cans on

[tastethefloor]

popping from the exhaust is related to too much fuel unburnt in one cylinder.
start with a plugs and coils check

or take it to a mechanic

[Chris sweets]

Is it easy to check the coils, how will I know if it's them?
There is a definite popping from the exhaust 90% of the time that the revs change

[tastethefloor]

I will check the plugs first, maybe I change them..

the valve timing could not be adjusted but could be wrong. a teeth more or less in one sproket in both exhaust or intake cam can lead to yours ymptoms

[MacV2]

Is it easy to check the coils, how will I know if it's them?
There is a definite popping from the exhaust 90% of the time that the revs change

That is more likely to be an air leak in the exhaust system somewhere...Check all the joints are fully clamped up tight...The std clamps rust very easily so one could have failed...

Let us know where you live & someone local may be willing to help you.

[Chris sweets]

Changing the plugs first it is then

[lloydie]

Check the vacuum pipe .

[Chris sweets]

I live just by leominster in Herefordshire

[AMCQ46]

I live just by leominster in Herefordshire

not to far from me, so if you are still struggling in May bring it to my workshop day and we can look at it and swap parts

[8541Hawk]

As I stated in your other thread, check the diaphragm in the petcock for leaks.

[VTR Phoenix]

As I stated in your other thread, check the diaphragm in the petcock for leaks.

Easiest way to check this is remove both fuel pipes from under the tank, leave the fuel tap switched on, if fuel continues to come out of the petcock then the diaphragm has a hole in it.

[Chris sweets]

Amcq where abouts are you? It's starting to get decent weather now so I'm dying to get out on it