Cold start trouble - Yamaha XJ600N

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During the last week when it's been very cold up here, my bike hasn't wanted to start in the mornings. The battery is well charged and the starter turns fine but the engine just won't catch.

When it finally does start (can take up to 15 minutes of trying, not continuous), it runs a little rough and will cut out after 5-10 minutes. Let it sit for another minute then it starts fine and runs well for the rest of the day.


I convinced myself it was carb icing and on Sunday I completely failed to find a shop selling the right fuel additive...so consoled myself with a copy of the Haynes manual. In the manual I read about testing the carb heaters and how they don't run when in neutral or with the sidestand down. So this morning I turned on the ignition, put up the sidestand, and put it into 2nd gear for a minute or two. Popped it back into neutral and it started first time.

Was this luck, was it maybe not as cold last night, or do you think getting the carb heaters to run before starting the bike did the trick ?
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Professional Uberslacker
2006 Kawasaki Z1000 - Black at the front, airbrushed fade to red at the back.
1998 Kawasaki KDX 200 Enduro project bike

[instigator]

It was nowhere near as cold as last night Gordon, I could ride along with my visor open without tears streaming down my face!

Try that method again when its been as cold as it has before and see what happens. I think that would be a good way to find out if it is indeed the carb heaters.

Complete bugger this carb icing stuff is. Makes my ninja sound like a gargling dog that hasn't been fed for a century when going about 40mph along on the motorway.

[JeffT]

[Kickstart]

Hi

I would doubt it is carb icing. Carb icing occurs when the cold air rushing through the carb collects the fuel and takes a load of heat with it, making the carb VERY cold. Then the moisture in the air condenses and freezes on the inside of the carb. As such I would expect it to need to run for a while before the problem occurs (so that might well be why it is dies after a short while when you finally start it).

Also, if you look at the Divvy carb heaters they are an odd design. It only heats the fuel in one float bowl, and then has small pipes to transfer fuel between the float bowls. Doubt it is particular efficient in heating up the fuel rapidly. Also suspect that it causes problems with flooding the l/h cylinder when parked on the side stand.

I know my Divvy was particularly sensitive to dodgy spark plugs. They would be the first thing I would check.

All the best

Keith
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