question for other maxi riders

Jason Luther /

i have a one speed 1.5 hp maxi. no matter what jet or needle setting i use, there is always a part of the throttle range that the ped four-strokes, always under full throttle usually about 3/4, then i give it a little more or less throttle and it stops. i have two carbs (one i bored out to a 14mm) and its the same. is this indicative of bing carbs? ive written it off for a year, but i was just thinking about it today as ive pulled it out of winter hibernation. i have two other peds, both with dellortos, throughout the whole throttle range, its a smooth as silk. oh yeah. when you pull it out this spring and go for a nice long ride, make sure you have enough gas in it. wives dont enjoy bringing gas to their stranded husbands. -jason

Re: question for other maxi riders

Ben Van Zoest /

70 years old engineering as good as it gets...

Primative for todays standards.

Re: question for other maxi riders

i just got my puch up and runing after sitting for a couple months, i am about to ride to work, terribly excited

how about messing with the air? does the throttle cable need to be tightened, is it not opening all the way? or is the choke sliding down?

what about drilling some holes in the air box?

whats your plug look like

Re: question for other maxi riders

seems far fetched but all i can think of is the needle taper is wrong.. Bings are criticized for lots of stuff but that sounds more like a tuning problem.

deliberately doing a plug chop during the 4-stroke problem should confirm it's actually rich misfiring.

Re: question for other maxi riders

Xxxxxxx Xxxxxxx /

sounds like fuel air to me. either too much fuel, not enough air or too much air, not enough fuel. i'm going to guess without looking at it that you either have a dirty or malfunctioning choke slide, not enough air getting through the airbox, or you have a dirty needle jet that may be getting hung up in your float bowl. Joew may be right about the needle taper as well but if you haven't switched anything around between carbs i doubt it.

what setup are you using (carb/intake/exhaust/jet size)?

jay

Re: question for other maxi riders

Jason Luther /

so this isnt a common bing problem. actually the top end of the carb (including needle) was used on both carbs. when i got the bike, it had a 12mm carb with 58 jet, ive since modded the stock exhaust, drilled out he carb to 14mm, tried all different timings, oped up the air box, im now running a 66. plug chops look fine. each thing improved performance quite a bit, but the 4 stroking is consistant. i know its 4 stroking because if i let a friend ride it, and they dont 'throttle out' of the 4 stroke, the plug will foul. i tried a hotter plug, but the only one i could find B4HS had the extended insulator and it would kiss the piston. its really no big deal, it only happens one point in the throttle, but its still kind of perplexing.-jason

Re: question for other maxi riders

yeah my bing runs fine,

what exactly happens, do you open the throttle all the way and as it becomes wot does it start to bog out?

when i first got my old red bike running fine it was four stroking but i think i just gave it some more air and a detailed cleaning to make sure the choke wasnt sticking and it ran fine,

i just set up my bike today with a new pipe and air filter and its running fine, i think i need a slightly larger jet but its not four stroking or anything

Re: question for other maxi riders

Jason Luther /

it only 4 strokes at less then WOT. but if i give it a little more or less gas then it stops. i mean, i can tune/repair a moped all day long, but this just wont go away.the only thing that may shine some light is the fact that the little washer that sits above the needle "clip" has always been missing. i just cant see how it would affect things though. -jason

Re: question for other maxi riders

Xxxxxxx Xxxxxxx /

every little thing counts for sumthin in such a small system. somebody put it there for a reason.

anyway, i also have had this problem when i had my swinger tricked kinda like yours. i was just attributing it to the motor starving for more fuel/air when i was easing off my throttle. I would feather my throttle during accelerationand then just open her up once i got into the midrange.

it is an altered carb. sometimes they get funny.

Re: question for other maxi riders

if the needle / clip is not totally secured under the spring i guess the needle could be sloppy at some throttle opening.. but that clip is held down by the needle even without the washer.

i had a bing with a loose choke retaining mechanism.. the choke would vibrate down all by itself just from it's own weight... but that doesn't explain a crappy fuel mix that cures itself at.. hmm.. yes it does..

Im thinkin the choke vibrates down and then , at full throttle the slide (which has a shelf that catches the choke) opens your choke slide back to the top..

you undestand what i mean?

Re: question for other maxi riders

_but that clip is held down by the needle even without the washer_

i meant to say "but that clip is held down by the spring even without the washer"

anyway, i think the choke is slipping down.. full throttle mechanically pulls the choke wide open.. i

Re: question for other maxi riders

Xxxxxxx Xxxxxxx /

that would make complete sense!

Re: question for other maxi riders

Jason Luther /

it does make sense, except the little prong on the choke plate that fits into the notch on the side would keep the choke from closing if the throttle was open. and this happened even with the stock unmodified 12mm carb. when i first got the bike it had a 58 jet, and wasnt getting enough fuel. past 3/4 throttle the motor would bog wayyy down. even _then_ it had the 4 stroking phenomenon. thanks for the input -jason

Re: question for other maxi riders

Not only did my choke shaft groove slip off the spring/prong, the choke plate never actually rose completely out of the bore, so some choke was always applied... hadda modify it a little.

I gotta admit i don't really like Bing's smaller carbs much.

Re: question for other maxi riders

Jason Luther /

yeah, im not too impressed with them myself. ill check out the choke because thats about the only thing i can think of. unless my fear of seizing an engine is letting it run too rich, but plug chops and preformance say otherwise. ill make a little washer too, just to ward off needle flutter, now that i think about it, the little needle clip was cracked, so i guess potentially it could move a little. but under the "weight" of the spring, i dont know.....-jason

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account