Flash 3.26Q

[Wheelman-111]

Greetings:

The ADV pipe is great, nice quality and sharp but not-too-loud bark. I inadvertently did my first fenderbending wheelie this evening. Gotta remember go cover that left brake of have more underwear to wash.

Once the engine warmed however, it started that missing thing again. Like the ignition cutting out or the bowl running dry. I no longer believe it is due to jetting but to faulty assembly somewhere. I'm out of time and Gumption to disassemble for now, so top speed testing will have to wait.

[bonesv]

Well, similarly, I was out late last night for a quiet ride on the daily rider, pushing 50 for about 9 or 10 miles, took a stop at idle, when I rode off again it felt like it was hot and "missing" fire or low fuel in the bowl, just as you described. So I limped it home, sputtering and thinking that maybe the last fill-up had some h2o in it, so this morning I fired up and it was still sputtering. Pulled the carb, fuel filter, cleaned thoroughly, drained some gas to check for h2o, re-assembled and fired right up strong. Dropped it down off the bench and , same crap. Mystified, I pondered, could it be electrical? Hmmm. Easiest to fix was swap the cdi unit with a known working unit. Fixed it!
Hope you will have the same luck as I did, Wheelman 111.
Thank you for the update on the new pipe, Funny about the jetting, maybe different pipe length?

[Wheelman-111]

Greetings:

Thanks for the kind wishes, Bones. It sucks to start over, and while I was feeling pretty frisky to pull off the motor and go over it the first time, I'm pretty bummed at the prospect of doing it again.

I don't have a Known-Good module to swap. In any case, my Rule is that if it was running well before and not afterward, chances are pretty darn good that I did it. That semi-flat O-Ring could explain it. It was cooked into the mating surface on the cylinder block, which means some of the material is no longer on the ring. It sealed well cold, but maybe once the engine warms there's not enough Viton to keep the pressure in the Chamber.

A fuel-flow issue wouldn't happen only with the engine fully warm. Still could be the Module, but I'm gonna buy a gasket set from DayWot and start over when I get some Gumption back. I really want this Civilized pipe to work...

[bonesv]

I have another extra known working cdi unit. I could send it to you to try.
PM me with a mail box and it's yours!

[LMH]

Why not try a good ole metal gasket to see if it stops the problem wheels? Even if there is a slight drop in compression It would stop your problem of leaking to see if that was it.

[Wheelman-111]

Greetings:

Thanks for the offer, Bones, but I'm 99% sure the problem is in the engine assembly and/or worn seal stuff. If correcting that and retuned jetting fail, I may take you up on that kind offer.

LoveMyHonda: Not a bad thought, but I don't have a 47mm head gasket handy. Plus the groove in the Polini head may create seal issues with a conventional gasket. Anyway an O-ring head is designed for zero clearance, and adding a gasket will decrease compression some. I've ordered a Corsa Gasket Set from DayWot and will re-Gumptionize when it arrives.

Y'all are nice to try to help, but I'm sure to turn up the problem sooner or later. If not, I've had a Hankerin' to try one of RedEftPerformance's MHR cylinders. I get to split me some cases to widen the boost port, YAY!

[bonesv]

I've heard the cdi failure is rare and was not my first thought. Just got lucky on the second try, after the infamous dirty carburetor/bad gasoline routine that you usually hear as a "try this first" suggestion. Best to you, wheelman.

[LMH]

Being as you have the corsa for a couple of them, the MHR will honestly feel like a lamborghini if the Corsa was a ferrari. Its the only way I can describe it. The polini is refined and fast, and super expensive, but when you get down on the MHR it comes to life faster and with a better exhaust note. My friend described my MHRs exhaust note as "Ricer sound" if that makes any sense.
Im currently trying to get another piston and seal set from Redeft.
Beware the pistons may not be as forgiving as the Corsas, first time it hit close to 400 melted the dome and the viton. But made it home Went from 300-398 in a second going up a hill, this was my first lesson (not the last) in what lean sounds like on an expansion chamber.

[LMH]

Also I dont believe, by the seat of my pants, Ive never gone faster on the KymcoZXs than with the MHR, pulling the front wheel at near any speed. Ive been riding my Corsa powered Zxs all summer and I got the itch for the MHR again.

[fastplastic]

[Wheelman-111]

Greetings:

I experienced the difference Love mentions on my Flash I and II Aero engines. Both were 47mm/65cc and both were cast iron. The Polini was more refined but a bit softer on power. The Malossi definitely had more juice but felt "brittle" and far closer to a full-on race cylinder, thus more fragile. I managed not to seize it, but also noted wild temp fluctuations and had the good sense (for a change) to back off, or even pull over and let it cool down. Living dangerously would be far more attractive if it weren't my Daily Rider. Still I can't resist the challenge.

[Wheelman-111]

Greetings:

A disturbingly large fuel puddle under the normally sanitary Flash told the sad tale of User Error. I had installed an OKO REBUILD KIT without paying much attention to the float level. Also established that there's no need go downjet when going ffom the PG Short go the ADV, as it flows at least as well as the PG, particularly at low RPM. With the 45 Pilot, my air screw was only 3/4 turns out. Still, the best part was no stumble/stall now.

Wheelie-generating power remained, as well as needle-burying power, albeit at 500 RPM lower. It's a bit quieter especially off-throttle, but just as much pull as the Short through 55MPH. TOP speed test to come.

[LMH]

Gratz on fixing it!

[Wheelman-111]

Greetings:

Added a little length of line to the bowl overflow outlet. It'll give me some warning of an Impending Puddle or it'll cause the whole crankcase to fill up if I keep forgetting to shut off my manual valve.

FOKO26mm.jpg (95.39 KiB) Viewed 4895 times

Thanks for the 'Gratz, but I'm puzzled. I actually have two different #45 Pilots. The one in there now is a Gin-You-Whine Keihin "K"-emblazoned 45, while the other came from some cheap knock-off carb I had. With the Keihin one, my idle speed starts dropping quickly as the air screw reaches 3/4 turns turns out. Even turning it all the way in to seat the screw doesn't kill the engine. The other (cheapo) 45 idled best at 1.5 turns out. Now I gotta see if the original air screw behaves differently or if I've managed to create an air leak somewhere else. 'S always somp'n.

[LMH]

Ive noticed arechi (ar) jets are larger than OG keihins if that helps. a 45 Ar is more like a 46/47 if that were possible.