Hi All, I hope you can help me, I have a 2005 ish Rev3, last time out it started revving faster & faster on tickover as I went along I had to keep unsrewing the stop on the carb, at the same time it started knocking under load, would not start at all the next day. I spoke to some of the guys and one said to check the stator, so, I've had the stator rewound, nothing, put on a new CDI black box, plug. When I kick it over know it won't do anything unless I give it full throttle and all it does it kick back like a good un! To me it seems like the timing is out but when I took the stator plate off it looked like the only place it's been although it is towards one end of the slots. Can someone tell me in idiot language how I check the timing please.I have had the carb off and blown it all through.HELP please, Tone.

Knocking under load can be main bearings, also when main seals go this can sometimes cause the reving you are experiencing.

I would take barrel off and see whats going on inside.

Thanks Rev3, If it's as you say would that stop it from starting?

It is not possible to absolutely accurately check the timing on a Rev 3.

If you look at the Beta UK website you will see that it is set up by reference to the position of the backplate retaining screws relative to the slots in the backplate. This differs by model so you need to look for yours. Unfortunately this leaves you reliant on the manufacturing quality of the ignition system (you can find comment on here indicating that this may not be of the highest) as to whether it really sparks at the correct distance before TDC.

Normally timing is quoted in either degrees or millimetres before top dead centre so that you can at least mark the flywheel and check by strobe to see that the system is producing the spark at the correct moment, if you have the motor running. Alas even the head honcho in the workshop at Silsden does not possess this information though he told me that using the method above seems to "get it about right". Not entirely satisfactory.

I know on my GG the plug was getting oiled up which stopped it from starting when the main seals failed.

Have you inspected it for a split in the carb inlet rubber?

Thanks guys for your help so far, I have removed the barrel there is sideways movement but I can't detect any up and down play. Can you replace the main seals or the big end without removing the engine?