Float height doesn't make sense??

[Jakobi]

Is it only going from closed to WOT? Does it still do it when rolling to WOT?

[Davehuge]

Hi Jakobi, it still won't pull WOT when rolling the throttle open steadily.

185 Main Jet arrived in the post today, so will fit it tomorrow and see what happens. Will also do a couple of plug chops.

I'm beginning to suspect I have an air leak, making preparations to replace the left side crank seal, will have to order a flywheel puller.

Thanks, Dave.

[swazi_matt]

Or borrow one from a ktm friend who has one

This is a smart way to remove the seal as well
https://m.youtube.com/watch?v=iQwulUnPxew

[Davehuge]

I'm happy to say I've now fixed my carburettor setup.

Just to recap... after adjusting the airscrew and needle position, it was running really nice from ZERO to 80% throttle position, but it just wouldn't pull or rev cleanly at Wide Open Throttle.

When I bought the bike, the float height was set at 20mm. I reset it to 16mm which seems to be the recommended height, but the carb overflowed at the slightest movement of the bike. I've now set it to 18mm and it's working well.

Originally the carb was fitted with 175 main jet, I thought it was running lean at WOT so I tried a 180 and then a 185 but it was clear the problem at WOT was worse. Clearly I had misread the plug after the plug chop and it was actually rich.

I fitted a 170 main jet and that solved the problem, it now pulls and revs cleanly at WOT, the bike's a missile!

All the best, Dave.

[Joginen]

I got the same problem as u had. I tried also 175-182 mj, and always bogging on WOT area, absolutely poor. Now on 170mj is clear and powerfull. Don't know why my bike also likes so small mj, but only thing what matters is that it runs fine.

[Davehuge]

Hi Joginen

Yes, I also have to run with my needle on the top clip position (leanest) but it does run really nice like that!

All the best, Dave.

[Jakobi]

Sometimes on the older bikes the needle seat actually flogs out and then allows a bit more fuel to come up past the needle at any given position.

[Davehuge]

Originally Posted by Jakobi

Sometimes on the older bikes the needle seat actually flogs out and then allows a bit more fuel to come up past the needle at any given position.

Yes, a good point, that sounds feasible.

Cheers, Dave.

[Jakobi]

When I say needle seat, I mean the actual orifice that the needle runs through (emulsion tube?).. not the seat that the float needle seals against.

Another possibility is that the choke circuit is allowing fuel to pass.

[Davehuge]

Hi Jakobi

Yes, I understood that's what you mean't, I call it the needle jet.

Yes, when I stripped the carb I checked that the choke closes fully and seals nicely.

Thanks, Dave.