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Help/ ideas please

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RGP750:
Hi All
KO 180 miles since rebuild, first 120 miles running great.
Last week went for a ride and stopped running on number 4, plug wet so thinking plug.
Tonight swapped number 4 plug with number 1, initially ran well but after 40 miles number 4 off again.
I got home and checked exhaust temperatures. Number 2 was 20deg the hottert but i seem to remember
this can be due to heat from the front disc???.
number 3 was next then 1, and 4 way behind, but still hot enough 300mm from head to make me think it is still firing
although not fully.
any ideas welcome please.
oh new coils and leads.

K2-K6:
Check compression and then valve clearance on number 4 to make sure nothing obviously untoward.

RGP750:
Thought i would try that next, just don't want to know compression down after all of the re build.
I'll let you know the outcome when i have done it.
cheers mate.

K2-K6:
Yes you'd hope not after just putting it together, sounded as sweet as anything when you ran it at Ardingly.

Something else I do that is quick and no cost, run it in as dark lighting conditions as you can find and have a look at the HT lead to see if there are any tracking leaks on no 4. I've had things like that run me ragged before.

MrDavo:
You've tried swapping the plug, next time unscrew and swap the plug cap from the lead with another cylinder and see if the problem moves with it.

Pre rebuild I kept fouling number 2 plug, a resistance test on all 4 plug caps with a multimeter showed a massive resistance on number 2 compared to the other three, a new cap solved the problem.

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