i have this v1, im happy with it's performance but i ld like to take advantage of all its speed WITHOUT putting a kit on it, is there a carb i can put on that might add some low end speed, the carb that is on there right now is a delorto 14,12 with a size 52 jet.
this is just an idea -cal
Dellorto Sha 15.15
What kind of speed do you want, acceleration or top speed?
Carb upgrades to 15mm are probably beneficial for stock, plus an exhaust, and a regear depending on what you want.
Im not a V1 but assume you could change clutch setup too.
Kinda depends on your time/money
i am mostly looking for a small upgrade in low end acceleration but id like to not spend much money on it. the top speed doesn't matter to me as much, like i said this is just a "hmm maybe this could be better but it's good where it is" kind of thing
I just souped up a stock v1, went from about 28 to close to 35. Doesn't sound like much but makes it very rideable.
Sha 14 (15 would be better but this is a free used carb) with a 62 jet and opened up air filter. I've already got the bigger intake that's like 14 stock but check that you don't have one of the tiny ones.
Stock motron exhaust with the restrictive outlet cut off, didn't cut off the whole baffle just the last assembly with the 2 discs and tiny tube
Ported stock cylinder, 1.5mm up on the exhaust and about 2mm wider each side. Intake didn't go much lower but maybe 2mm wider each side, can't remember exactly. Removed stock head gasket.
From here the next best thing would be a cheap circuit pipe or slip on chamber. I built a really similar engine to this back in the day and had it up to 38 with just an ev racing pipe, even faster with a 15 Bing but I never gps'd it.
Stock v1 porting is crazy restricted, even on the 'fast' cylinders. It doesn't take much to get them over 35.
Obviously check bearings, chain, tires, breaks, all that stuff for drag too. The cheap stamped brake plate that a lot of Italian bikes have likes to hang up.
Knew I took a picture of that port job.
I have a puch proma circuit I might end up throwing on there, but I think I'm gonna swap it for a tomos a35 cylinder with a spacer now instead.
I guess I have already done one of these thing by accident, my exhaust is straight piped so I'm getting as much flow as possible, I'm not very sure about porting (never done it) but I might buy a 15 or 14 and throw it on there and see what that does. I do find interesting that with a little bit of modification you can milk so much power out of a little two-stroke
> cal mcclung wrote:
> -------------------------------------------------------
> I guess I have already done one of these thing by accident, my exhaust
> is straight piped so I'm getting as much flow as possible, I'm not very
> sure about porting (never done it) but I might buy a 15 or 14 and throw
> it on there and see what that does. I do find interesting that with a
> little bit of modification you can milk so much power out of a little
> two-stroke
A Straight pipe is a no-no with a two cycle engine!
A expansion chamber is the supercharger with a 2 cycle engine. With only a straight pipe you’re getting unburned charge thrown out of the pipe instead of being pushed back in the cylinder to make power etc.
Stock moped exhausts use some kind of restriction to make a halfway of a powerband most times because if they used a good expansion chamber they would make too much power.
Just removing stock restriction most times remove torque and ruins the powerband though it might feel faster because it’s louder, you may get a mile or two faster at peak rpm if it was restrictive (while losing power everywhere else) but you get nowhere near the gain with using a good performance chamber pipe.
> cal mcclung wrote:
> -------------------------------------------------------
> I guess I have already done one of these thing by accident, my exhaust
> is straight piped so I'm getting as much flow as possible, I'm not very
> sure about porting (never done it) but I might buy a 15 or 14 and throw
> it on there and see what that does. I do find interesting that with a
> little bit of modification you can milk so much power out of a little
> two-stroke
Pics of your exhaust?
Well that's very interesting news to me I just assumed that the less restriction the better the exhaust could flow better the power, I do have the stock restrictor that goes in the pipe so I'll hammer it back in there. When I bought my moped the restrictor wasn't in the exhaust pipe so I just assumed that there was a good reason to not have it in there so I never messed with it.
Pipe and restrictor
Just regear the rear sprocket for immediate low end gains at minimal cost and time
For low end help, grab a circuit pipe. A Sha will never help with low end as it is a single stage carb using one jet with no needle. Sha carbs are super easy to tune to get running, but almost impossible to make perfect at high and low end.
Gearing and a circuit pipe will be your mose problem free way of increasing your low end power. You will be sacrificing top end speed however.
That's not the same exhaust I have but it's close, there are 2 other baffles in mine before that one so it's not a straight pipe just 1/3 less restricted.
I can't say for sure how much each small change helped, but overall it's faster with more torque everywhere. I just got a chance to ride it today and it can go up my (hilly) driveway from a dead stop which it couldn't do before, so cutting off the last baffle definitely didn't kill my torque.
I redid the whole bike for the cost of a petcock, tires, tubes and grips just to challenge myself not to spend any money otherwise I definitely would have put a pipe on it. If you actually want to see real gains, the 80-100$ spent on a pipe is money very well spent.
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