Z1OwnersClub GB

A few weeks back I asked about a flat spot at low revs. I swapped the carbs from my z1r and it ran beautifully, put them back, still flat spot. I also noted that pipes 3 and 4 took a bit longer to get as hot as 1 and 2. I put new keyster parts in carbs 3 and 4, still flat spot, I can get a nice blue flame on 1 and 2 but only yellow on 3 and 4, even if I screw the mixture screw full in or full out same yellow, at a loss, are the carb bodies knackered?

Still probs eh David? have you checked the choke plungers,cant remember if i asked before,i do have a set of incomplete Mikuni carbs off a Gs i think but dismantled for parts,one body has a busted float post,but all bits like choke plungers ,floats etc,pretty sure parts may suit your thou.If any help to you £30 plus post...Paul J

Thanks for the offer Paul, chatting with Dave Marsden today, he has a couple of sets he will sell if I need them, it's really frustrating, can't see owt wrong with them, just can't get the buggers to work right, if you have the bodies for 3 and 4 in good order I might take them off you.

if its only on 3-4 i would swap the coils round if you haven't already done so ?

I had a similar problem, I fitted a pingel fuel tap and the bike ran a lot better.

z1bman wrote:if its only on 3-4 i would swap the coils round if you haven't already done so ?

Hi Paul, it runs fine with other carbs, so it's deffo a carb issue.

Zedorset wrote:I had a similar problem, I fitted a pingel fuel tap and the bike ran a lot better.

I will swap the fuel feed pipes see if it changes, you never know.

DavidZ1R wrote:A few weeks back I asked about a flat spot at low revs. I swapped the carbs from my z1r and it ran beautifully, put them back, still flat spot. I also noted that pipes 3 and 4 took a bit longer to get as hot as 1 and 2. I put new keyster parts in carbs 3 and 4, still flat spot, I can get a nice blue flame on 1 and 2 but only yellow on 3 and 4, even if I screw the mixture screw full in or full out same yellow, at a loss, are the carb bodies knackered?

If you screw the mixture screw in and out with no change there is your problem, surely. I'd be very thoroughly blasting out those passages and sonic cleaning those bodies.

does it have the mixture screws under the carbs?

Yes screw is underneath, it's the fuel mixture screw, so the nrp carbs man told me, had the carbs off again today, all the passage ways are clear and we'll flushed out, got me truly baffled

I bought two new keyster rebuild kits for 3 and 4, fitted the new parts, I wonder if the new parts are at fault. Can't see that tho .

I have a set of A1 thou 26mm carbs, non vac tap, they have been sonic cleaned, float levels set, slides bench set, 15 pilots 102.5 mains, if you pay the postage to and fro you are welcome to give them a go.

have you tried using a couple of the old mixture screws?

have you tried using a couple of the old mixture screws? there are small holes in the throat of the carb body by the slides this is the main cause of not being able to correct the mixture

kev edwards wrote:I have a set of A1 thou 26mm carbs, non vac tap, they have been sonic cleaned, float levels set, slides bench set, 15 pilots 102.5 mains, if you pay the postage to and fro you are welcome to give them a go.

Thanks for your kind offer Kevin, I know it's the carbs for sure, so no need to try other set, thanks again.