Modern Vespa

Hi all,

Anyone running a DR 85 on their 50 special engines?


I'm looking to increase some performance without breaking the bank.

Anyone running it with stock exhaust and a 16 carb?

Your help and suggestions are always appreciated.
Thank you.

N

works. change the gearbox to 24/72.

if you can swing the extra bucks I'd suggest the polini for 40 more. that way you can upgrade on the carb and pipe and have something that isn't as much as a stop gap to a bigger more powerful engine.

but 100% agree with gick. it'll all work, but you definitely need gears. (I probably have a set kicking around)

i run a dr on my v50 but with 16/16 carb and preformance exhaust. You can try the standard carb with bigger jets but you must also allow for more air inlet somehow.

Thanks everyone for your responses. Much appreciated.

I'm sticking with the dr85 because I have the cylinder kicking around.

I was planning on installing the v90 primaries (22/63) bc I have those kicking around too.

Debating a 16/16 vs 19/19 carb. Unsure if I could just upjet the 16?

I'll most likely buy a banana exhaust vs stock exhaust. Unless I can manage with a stock exhaust —-would buying a larger manifold help?

Again—-trying to be cost effective as I can.

Thanks again everyone.

Hi,

I'd say 22/63 is too long for a DR85. I'm not shure if you'll be able to use 4h gear.

V90 Primaries would be too long, the 90 engine is the 51mm crank so produces more torque than a kitted 50 on a 43mm crank.

You would be better with 24/72 and then you have the flexibility of the 21-25 tooth pinion.

while trying to be cost effective as possible, and I get you there, you're still gonna have to split the cases to upgear. so gaskets, seals, bearings... you're half way to a crank by then...

go 19 the 16 is lack luster at best. banana or a sito at minimum. if you can scoop a polini or Leo Vince on the cheap then I'd do that.

you're most of the way there- 4spd and cases is the heavy lifting. all the rest is doable!

Greasy—-I previously purchased the seals/bearings/gaskets so I'm ahead there. I'll be splitting the cases anyways just to review the work previously done. I do believe the engine is a 4 speed however. Noted in the 19 carb.

So the general consensus is that the 22/63 primaries are not appropriate for this engine/set up?

I figured that the 22/63 would be sufficient based on SIP recommendations for that cylinder.

I may have to go back to the drawing board......

re: drawing board... where do you *want* to be and what is your budget?

there's things you can do, and there's like, more, better things you can do and there's also the whole things you can do and set up to anticipate bigger and betterer things.

smallies are like a combo plate. you got your 1/4 bird, two sides and a soda

you want dark or white, you want slaw and beans or mashed and Mac, coke or water?

cases and four gears is most of a smallie. primary and a crank is the call behind a top end. that's where the decisions have to be made.

I can see that greasy. So many variables to consider.

Honestly, I want this scoot to be running and keep at an honest 70-80 kph. I have larger scoots that can satisfy my speed bug.

This smallie has become a learning curve/money pit. Hence me being tight.

Essentially I would like to keep the original crank and gear box. Change the cylinder, carb and exhaust. And change the primaries if I must to optimize.

Thanks for all your input.

N

i would not change the cylinder if you plan on staying with stock gearing. . . .unless what you have is blown up and you are tight like spandex.

I would put in the 90 primary. Blue print the cylinder. Tighten the squish clearance to 0.5mm. If you can get an electronic stator, it will run higher advance too. This will get over the tall gearing issue. Will be a lot of fun and good for 100kmh head down.

well, you already have a cylinder, and you have the 90 set, so I'd jam with that. you've got 4 gears so that's bueno.

carb wise, the 16 will work but you're gonna need to jet and that's the fat man in line at the turnstile. keeping it stock a 19 yields dividends. stock or stock-ish with an aftermarket dell or polini carb or carb/intake combo is jam and money well spent.

for this set up, exhaust wise you're on it with a banana or sito. even a noise maker pseudo chamber (Leo, point, malossi) would be good

like jack mentioned, if you don't have it and can swing EI do so. I'll add that you should go lighter on the flywheel too.