At a loss, anyone in Hampshire help? Still won't fire

[stukeith]

Ok still can't get firing right. So far I have done the follwing

new fuel lines
new carbs striped us cleaned, rebuilt with new jets, gaskets and balanced
new engine 
new coils
new caps
new ignition
new fuel tap

the only thing I have not replaced is the fuel pump and cdi. All 4 cylinders are now hot, but only runs on choke and won't go past 4K. Plugs are all sparking, they were black. I can't believe it's the engine.

is there anyone in Hampshire if Dorset that can pop down, and maybe let me try their carbs on my bike? I am going to try and by pass the fuel pump tomorrow see if helps, if not what next?

[stukeith]

Bike not run more than a few seconds since carb rebuild by shop. Put fresh fuel in, all plugs good spark. It starts, but really rough running and no idle without choke

[satnav]

Afraid I am not in Hampshire. But my five pence worth is it sounds like the carbs need setting up. When they were rebuilt they will have just dialled in some approximate settings for the mixture screws.

[m40man]

Feb 28, 2016 1:19:06 GMT stukeith said:

..... carb rebuild by shop. Put fresh fuel in, all plugs good spark. It starts, but really rough running and no idle without choke

I don't wish to denigrate the shop, I guess it could be something else, but regardless of balancing & regardless of setting-up (there's little to set up - no adjustments are possible except for the float heights & the needle heights (latter of which should be left alone & shouldn't normally have interested a shop) or the mixture screws, which also should have been left in situ & not tightened or backed off at all), IMO I'd should expect the bike to rev once warm, even if a little spluttery at first, or not so smooth as you'd wish, or with an erratic tickover. Not getting off choke & not revving = blocked jets to me.

Your symptoms pretty closely match those I had on my 900 (always needed choke & wouldn't rev) before I cleaned the jets myself, hence my scepticism about the carb cleaning.

[bobh]

Feb 28, 2016 15:08:49 GMT m40man said:

Feb 28, 2016 1:19:06 GMT stukeith said:

..... carb rebuild by shop. Put fresh fuel in, all plugs good spark. It starts, but really rough running and no idle without choke

I don't wish to denigrate the shop, I guess it could be something else, but regardless of balancing & regardless of setting-up (there's little to set up - no adjustments are possible except for the float heights & the needle heights (latter of which should be left alone & shouldn't normally have interested a shop) or the mixture screws, which also should have been left in situ & not tightened or backed off at all), IMO I'd should expect the bike to rev once warm, even if a little spluttery at first, or not so smooth as you'd wish, or with an erratic tickover. Not getting off choke & not revving = blocked jets to me.

Your symptoms pretty closely match those I had on my 900 (always needed choke & wouldn't rev) before I cleaned the jets myself, hence my scepticism about the carb cleaning.

My thoughts exactly. Not had this problem on a Divvy, but had exactly these symptoms on another Yamaha. After removing and cleaning out the pilot jets - which were clogged with jelly-like fuel residue - problem solved.

The pilot jets are tiny - you can only just see through them if you hold them up to the light at the right angle. The best way to clean them is with an air jet and/or squirting carb cleaner solvent from an aerosol through them. I can't rememebr offhand whether they can be removed with the carbs in situ on the Divvy.

Some recommend adding IPA (isopropyl alcohol, not beer) to the fuel to prevent this - it also helps to avoid carb icing in the winter months. Or use a fill of 97-octane premium fuel (Shell V-Power etc.) occasionally to clean things out.

Also, when leaving the bike unused for any length of time (say more than a month) it's best to drain the float chambers or run the carbs dry.

[bobh]

One further thought - if the plugs are black, it's very unlikely to be a fuel pump problem, since it implies too much fuel (probably from using the choke) rather than too little.

[stukeith]

right looks like its the carbs again. here is a vid I made 1st thing.


then I took the carbs off, jus to check,



after an hour of cleaning out she runs a lot better, dose this knock sound like the clutch rattle? its coming from the back of the engine I am assuming it is the little pin that the xj600 suffers from.

Now to get this thing on the road, just need to order a repair kit for the fuel tap, then insure for a month and then get mot'd

Ive just brought a pan european, so this will be a spare, or will sale off.

a tank of fuel and redex should sort the rest out.

[stukeith]

[cam7777]

Sounds like it's not firing on all 4, is each downpipe getting hot? When its running, try pulling a spark plug lead off at a time to see if there is a change in the engine note

[m40man]

Mar 2, 2016 18:06:33 GMT cam7777 said:

Sounds like it's not firing on all 4, is each downpipe getting hot? When its running, try pulling a spark plug lead off at a time to see if there is a change in the engine note

Agreed. Spray the downpipes with a water mist & ensure that each one sizzles dry so you know they are nice & hot. This doesn't guarantee they are all firing all the time, but if one isn't firing at all it's an easy way of singling it out.