Scooterotica

coaster wrote: ↑Wed Apr 25, 2018 5:04 pm Has the spitback mess improved with the move to 3%? just wondering as 4% is recommended for the GT240 kit and the oil from the spitback is really messy and with the rebored cylinder, I have gone down to 3% and it seems a little less messy.

Re you dyno results and inconsistent responses to jet changes, have you considered the possibility of an air leak or maybe damaged petals?

The pilot i was recommended was a 58, i did try a 48 and a 50 earlier today and you could tell it wasn’t fueling properly so went back to the 58 which feels right, in answer to your question by going to 3% and even with the 48 pilot didn’t make 1 iota of difference to the spit back.

Been back on to Mark as ive got an NK road on that I really like but he doesn’t, his answer is to ditch the NK and buy one of his clubman pipes which i don’t really want to do, but what i am going to try is the DT TSR Evo which to be honest was s**t on my last engine so I’d imagine it will be just as bad on this build but I’d really like to be proven wrong so we will see.

No air leak. I tried it when i dd the build about a 1000 miles ago and recently to.

Ive considered the reeds but its been like it from day one but will check again, apparently the reeds are off a Derby Senda moped.

Is that the 'shorty manifold with the 6 petals? I ran one on a 225 SR type barrel and was never confident that the rubber inlet stub was sealing all the way round but we weren't leak down testing back then. Did a check on my Read valved Avanti recently which has a similar rubber and it blew bubbles out all the way round and took 2 attempts to seal....scared to take it off now!

Yes it is a shorty, and yes it was a bitch to get to seal as you say.

Tried the tsr pipe again yesterday, first thing as im wheeling it off the ramp it clouts the ramp (wouldent want to hit a speed hump with this on) and as with the other build it wants to rev to the moon but with little bottom and mid range, hit a bit of headwind at 50, hard work to pull through it so back on with the NK road.

Update on this: couldn’t get the thing to run right, i somehow got the idea in my head that I couldn’t remember seeing any reed stops when I built it, so stripped it for a look but everything was fine and as it should be.

Tenby dawned and I’d been looking forward to doing it so set off alone and within about 25 miles i was covered in petrol in my attempts at fiddling with the carb to get it to run better, i was now down to about 48 mph , any more and the egt shot off the scale at 740 degrees C.
At this point I finally admitted defeat turned round and went home. To say i was pissed off was an understatement!

I took it to Martin at Chiselspeed the following Wednesday, he quickly ran it up on his dyno and commented on how quickly and how high the temps rose so its with him to be sorted out now.

my “guess” is barrel to piston clearance and ring gap be sure to tell us all what the problem is when martin sorts it for you

It’s a fresh engine with only 1266 miles in it , ring gap and piston clearance right at build.

Further update ! Picked up and ridden back from Chiselspeed yesterday 80 odd miles runs spot on cruising around 70 most of the way home on the motorway, egt never went above 580c.

Part of the problem was I’d sited the egt probe in the wrong place,.

Jetting wise Martin fitted a 50 pilot, 50 slide, x4 needle, 134 main jet and AV 268 atomiser, so now it runs clean off the bottom and all the way through and I noticed on the dyno chart there was a slight flat spot before at just over 5000, now there isn’t one so all good.

So no other faults, just needed jetting properly ?

drunkmunkey6969 wrote: ↑Fri Jun 01, 2018 1:13 pm So no other faults, just needed jetting properly ?

Well yes, that and the fact I’d sited the sensor in the wrong place, but in my defence I wasn’t aware there was a right or wrong place to put it.