I've just got my R1 5JJ (carbs) started, it seems to run OK, but number 4 exhaust manifold pipe doesn't get very hot. 1,2 &3 have turned a nice light stray colour, but number 4 hasn't changed at all.
I've checked the ignition system, everything seems fine.
Could it be a mixture issue, or blocked jets? The engine has been standing for about 8 months.

Any Ideas?

Steve.

Try swapping plugs and see if the problem follows.

I have recently had a set of new platinum plugs which had to be binned due to flooding during my early attempts to start my V6. £30 down the drain

Couldn't they have been put in the oven for a while? Works with my 'bird plugs if they flood.

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Originally posted by RazMan
Try swapping plugs and see if the problem follows.

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Does the enigne sound rough, or as though its only running on three cylinders? Try pulling number 4 plug lead and see what happens. It could be that it's not firing, or as you say the jets could be blocked. Take them out and blow them all through and see if it helps.

Hi Steve,

If the engine is standard like my 5JJ itll be running lean as hell. That wont explain why one cylinder isnt hot as the others of course but the carburation will be all over the place.

I started by checking my mixture screws, one of which was a mile out. Mine has the US spec carbs on it so the mixture screws are covered by small brass plugs which need drilling out to get to the screws. After that I blocked the small air jet next to the pilot air jet with a cocktail stick and the thing is off like a banshee.

If anyone had told me how badly these run (particularly the 5JJ it seems) when you ditch the airbox and fit a completely different exhaust, I wouldnt have believed them.

Mine is going to get a dynojet kit eventually but it is 100% better (and safer) than it was.
Out of interest, what colour are your plugs and are they the same across all cylinders? My headers were glowing after not long (I think no4 in fact wasnt as hot) after not much running which was clearly a lean condition.
Good luck and any problems dont hesitate to u2u or email as Ive had about a month of trying to solve mine.

Rgds

Rich

ive got a fuel injected r1 and i have the same problem on number 3 cylinder any body know how to cure this through the bike clocks .

Cheers Des

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Originally posted by RichieC
Good luck and any problems dont hesitate to u2u or email as Ive had about a month of trying to solve mine.

Rgds

Rich

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You wont see or hear a lean flatspot/mis until you put the car under load. Mine always revved cleanly and crisply sitting in the garage.

Rgds

Richie