Z1OwnersClub GB

I am trying to get the enging up to temp and need to hold the throttle slightly open so it will run - choke if fully on. I notice that left cylinders (1 and 2) are not a hot as other two - why would this be? i.e. placing finger on exhaust for 3 or 4 makes me go ouch whereas 1 and 2 are pleasantly warm.

It is not igntion related as the coils power 1-4 and 2-3 but the fuel line from the tank feeds 1-2 ands 3-4 respectively. Petrol is getting to the carbs due so the carbs need balancing or is it a choke problem? Any ideas?

more info,.

after another run;
cyl 1 = 21 C
cyl 2 = 37 C
cyl 3 = 158
cyl 4 = 180


Am I correct in thinking the carbs are cast as pairs and there is a linkage to join up both pairs to the throttle?

current tought is that when I was unfreeing the stuck throttle (cyl 2) I must have cuased the adjustment mechanism to move?

Anyone got diagram of how the cars are joined to gether? (haynes does not show this).

Hi mate, from your description I assume that the bike has developed a missfire since you took the float bowl off? I think it's unlikely that you have disturbed the carb balance by taking off the bowl in situ, if it's only just happened sounds like fuel, either not enough or too much.

Check you havn't accidentaly knocked off the vacum take off plugs.

haynes says carbs share one shaft plus took the carb lid off no.1 and could see the slider move in unison with the throttle so nothing has gone out of sync due to unsticking.

replaced pipe from tank to LH carbs as it was old and had a slight kink but no different. pretty sure that fuel tpa is ok.

so need to investigate ignition & compression.

got 4-1 exhaust - if unburnt fuel was being chucked out from 1 & 2, would not the exhaust be backfring?

Looks like 4 is leading
best to remove carbs,clean set slides,floats only if required &pilots refit.should solve your problem. clean out fuel bowl/tap check for rust in tank.and make sure the fuel pipe to 1&2 does not kink on the bend just behind the tap

silly question but have you took the spark plugs out from cylinders 1 and 2 and checked they are sparking? Not uncommon - especially on ngk plugs. If they are black and wet there is a chance they are not sparking and need changing!. If they are dry and sparking well then it is a fuel problem. Are you sure petrol is getting to the carbs for cyclinders 1 and 2 since you changed the pipe? Try and undo the drain plug an the float bowls and see if petrol leaks out, at least that way you will know petrol is at least reaching the bowls. If it is getting to the float bowls but not into the cylinders you will need to take the carbs off and check there are no blockages in the jets. When checking for a spark, dont forget to check the plug caps are working ok on 1 and 2 if you have not already done so.