Too large main jet

[djh66]

I now have it running lovely, changed needle to a GJH, back down to a 34 pilot and dropped down to a 112 main (118 was too big). Carried out various plug chops - nice colour, sounds crisp.
NOW HEARS THE STRANGE THING!!
This is on it's stand, as soon as I sit on the scoot, the tickover dies down, and will cut out if I bounce on the seat? This may have been the problem all along, but I can't seem to see why?

Help appreciated, again
Dave

[sdjohn]

Fuel line pinched when suspension engaged.

[coaster]

Fuel line pinched when suspension engaged.

Agreed, also check that none of the wiring to the CDI is tight on full suspension deflection (take the rear shock off so that it drops fully.

I might also be worth having a look at the air filter elbow if you have one, some are very soft and have been known to colapse when the engine is pulling hard.

Good luck with Skeggy

[djh66]

Thanks chaps.
I'd re routed the throttle cable at the carb end around the fuel tap rod, so put it back to how it was, and this cured it.Doh!

Hopefully now all sorted, will give it a run today, and reprt back. Before I move onto my next problem :biggrin:

[djh66]

Thanks chaps.
I'd re routed the throttle cable at the carb end around the fuel tap rod, so put it back to how it was, and this cured it.Doh!

Hopefully now all sorted, will give it a run today, and reprt back. Before I move onto my next problem :biggrin:

Well no it's not sorted! I'm just going round in circles.
Wants to die at half throttle, had to drop the clutch and rev.
Plug check - too light, will go to a 116 main
Running with CamLam rear exit fast flow, always seems to be a big air gap in it! But it's doing 56 secs. a pint!

[djh66]

I'm getting the feeling I'm barking up the wrong tree!
It still cuts out every so often, but I can keep it going if I drop the clutch and rev. I don't think it's the carb at all.
What should I be looking at? Switch? Regulator? CDI? How can I test these?

Cheers again
Dave

[storkfoot]

It's very hard to diagnose these problems from what's typed on a keyboard. I think it may still be your jetting though.

May I suggest you take off the filter and elbow and run it around the side roads going up and down the gears. Don't wang it down the bypass at full throttle (you'll be running leaner without the filter), but you can go up to wide open throttle briefly.

If it runs better, and you don't have to grab the clutch, and drop the revs to keep it going, it sounds to me like your jetting is still out.

Are your floats balanced and set at 21 or 22mm?

[djh66]

Hi Storkfoot, thanks for the reply.
It's not running through the airbox, direct in the carb. Although I have played around with the jetting, initially to eliminate 4 stroking a 1/4 throttle (see earlier posts) I'm not far off on the jetting, but all of a sudden it'll die (not seize) when being ridden (no probs on stand). I'm now thinking something is earthing when I go over a bump, maybe in the headset. I will check on Monday.
Dave

[nelson pk]

I was playing around today with a mates bike that seemed like a jetting issue but turned out to be fuel starvation. Did you say that the fuel line always seems to have air bubbles in it.....even after a journey?
Well this was my problem! If your getting air into the pipe it will vapor lock when you want to use some serious fuel (higher revs). If i took the pipe off carb and turned the fuel on, i had excellent fuel flow (1 pint a min). But whenever i connected it all up the bloody air bubbles would start appearing and would get worse the longer it was run for.
After much looking for where the air was coming from it ended up being a slight air leak on the carb and the bubbles were traveling back up the pipe.
If this is the case with yours, first of all make sure the pipe is tight round the carb inlet with something like a good fitting jubilee clip. Then (i've never had experince with pwk's) check any carb seals on the inlet side, for example dellys have a fibre washer on the carb inlet and under the float needle. I changed these on mine and no air bubbles and no starvation!

[nelson pk]

Just to add that i think you'll find that after a journey your fuel pipe should not have any air gaps in it unless you've disconnected the fuel pipe and then reconnected and turned the fuel on but this gap should disappear after a short journey. This sounds like your issue to me. Check your pipe rooting as well.
Hope this helps.