Modern Vespa

Hi all!

Anyone fitted a TMX 30 (with powerjet) to a rotary malossi 210 setup?

Anyone have any ideas of the jetting?

Current setup:

PJ 25 1.25 screws out
MJ 220
Powerjet 30
Needle 5DP39 (default was 5el68) clip in the middle

Seems to be running a little rich, I’m at sea level

Bump, anyone have any insights?

Thanks guys

I can't help much but by far the most common setups are Dellorto, followed by PWK. I've not seen barely anyone running Mikuni. This is probably why you are getting crickets....

Thanks for the reply!

I see the Mikuni seems popular in Germany... I’ve ran all 3, I started with the dellorto, which was a challenge to jet... ended up in a decent place but never had the pulling power of the PWK... but that always ended up running rich... so now ended up with the TMX... it seems to have the best torque. it’s great at WOT... but not quite there yet at idle and low revs...

I've spent over a year jacking around trying to get my PWK to jet in. But that's a different 40 page thread .

Power jet carbs are usually best suited to very high rpm (10,000+). What is the spec of your engine?

- Malossi 210 sport cylinder and piston, 1.72mm base gasket
- Scooter and service malossi 210 low compression cylinder head
- MAZZUCCHELLI 60mm rotary crank
-extended intake port to 120degrees
- Sip clutch basket with Honda CR80 clutch plates, straight teeth
- Nordspeed Camaro

Not sure if I’ve missed anything

Oh and gearing has changed, can’t remember what I’ve ended up on though...

Anyone used the PwK air striker?

Found it old invoice... 24/63 teeth

The 1.7mm base packer is going to put your timing up high, which implies you are after a high revving motor and peak power. Your gearing says otherwise. The 24/63 is very tall. It's what I use on my Pinasco 225 tourer, which is all about low down grunt.

Any ideas for a better gear setup? 23/62?

23/65 is pretty good for a 221

Set up seems like you were expecting 100mph. 1.7mm packer is probably good for 10,000 rpm and on 24/63 that is 100mph at 9000 rpm. Unfortunately a 30mm carb (of any make) on a rotary is not going to get you to 100mph.

If you put your PWK back on you could copy sdjohn for set up. Would save you a few years

For the way forward, as you have a sport and is meant for touring type riding, the base packer should come right down to about 0.50mm. Fix the squish at 1.2 or less. If you want to keep that gearing you'll most likely need a 57mm crank back in.

Thanks for the insights..!

Don’t mind changing the gearing... I’ve read of someone with a similar setup using 20/68...

I’m not after top speed if it takes forever to get there...

Ideally I’m after a setup which can handle city riding... on steroids...

Can’t be right at 20/68... apparently running on 100/90-10 tires

Bump

What gearing you have available? If you think you spend all your time in 3rd then it will need to be reduced.

23/65 with a 36 4th works for most, like it always did. If you are keeping the 60mm crank then the Sport kit will pull better than the MHR but but still not go near the 24/62. Easy to trim the gearing with a clutch cog or bigger tyre later on.

With the set up it seems like you wanted the MHR would have been a better choice but working with what you have the 0.5mm base I said before will be a little low. Maybe start at 1.0mm base and see how it goes. Will need to do something with the head to get the squish under 1.2mm.

Vader ran a TMX for a while on his old Malossi 221 and told me he was never happy with it. He changed to an Airstriker and found it much better... if you search for his posts you might get some jetting tips.

I was going to go onto SIP to see what gearing was available...

Sounds like 23/65 seems most sensible... I do want to keep the 60mm crank, I don’t have a shorter crank on hand...

Will look at my gaskets... I do like to have a more revvy setup, but maybe I need to balance it out

Oh man... that doesn’t give me too much confidence... I kinda like the TMX just because of the torque... but it does seem like they’re all Dyno setups... not very practical on the street

Oh, and do you know if it was on a rotary setup? Would be great to know if I can apply the learnings from Vader

No, reed. Now that I think about it the other reason to change was due to space restrictions... it was in his Super I believe.

Have you looked for similar setups here?
http://lfs.alexander-hepp.de/

That’s my go to website... so I’ve tried all the settings for 221 rotary setups... all not quite right... good for general direction...

I’ve setup my tmx similar to one setup in the list... but the gearing is insane... 20/68... means it’s a revving monster!

Did you ever get this dialed in? What did you end up with for jetting?

I had a “not bad setup” but it was on the lean side, especially 0-1/2 throttle.

I have all the needles from 53-58 and I just couldn’t get it with enough power without being too hot.

I gave up in the end and put a pwk carb with fuel pump on it... the main reason I wanted to add the fuel pump without drilling into the crankcases

Let me see if I wrote it down my last TMX settings...

Thank you for looking, working on setting one up myself. Ordered a handful of needles and jets myself. If you have any spare parts let me know. Mines on the cool side.

Do you remember how you ended up with that needle? Its the stock needle for a TM28.

It seems like the most common TMX carb is the 35mm version, I thought I'd try a 30mm TMX on my 260 but it just seemed like there was not a lot of needles and slides available and I could never get it jetted correctly because of that. I ended up going back to a 30mm PHBH, as there's so much more info and variables available.

I have been able to get everything except needle jets the 622 series isn't popular. I may see if I can find another one that fits, I think mine is actually pretty close. I thought it was running cool, but have found several people with a Pinasco 225 and it seems 200 -225F is normal. I have a hand full of 5 series needles. They are the same needles used in a few different carburetors including a TM28 or VM28 seems the naming nomenclature is a bit screwed up on the one. I have a TM28 in a box that a lot of the parts interchange. May pull it out and try, just to see if there is a difference between the two. Seems a lot of people are still using a SI 24 on the same motor.

I loved the SI24/sport combo, I used to just run a box pipe, SIP road I think, it was a great reliable combo. Once the tuning bug bites though...

Yeah I ended up with 6EN11-57, middle clip...

Oh I ended up swapping out the TMX30 with power jet for one without...

Yeah I asked around companies that sell the TMX... no one plays around with the slide... old dual carb MX would use it apparently... it’s a little surprising, because I think there is where the problem lies... but I’m thinking about the way it’s designed and it’s target market, maybe it’s not suppose to be used on low revving 2 strokes... because it runs great at higher rpms...

The PHBH is a great carb... the jets make a lot of sense, but the round slide just feels too old and soft...

I honestly would steer away from using an Si carb with a tuned engine... it’s nice and easy, but people who have used it on engine tunes that aren’t pushing the scooter hard, it’ll definitely run ok... riding it like a stock scooter... again, just the way it’s designed, it’s impossible for the carb to provide enough fuel even with the bigger jets...

I've had good success with SI24 carbs on tuned engines, mainly malossi 210 or 221 sport setups. I've researched and have done various mods as many people suggest, like opening up the float bowl chamber outlet to main jet stack, 5.2mm needle, modified float top, etc. Never seized one, always ran smooth, ability to go WOT with a nice colour plug. It's still a rotary valve engine and in no way liken it to a reed motor but for what it is, it's a great carb. As I said though, I've now got a 232 and a 260 quattrini both running reed intakes and 30mm dellortos.

It’s a good carb, it was designed for large frames... and for sure it’ll run smooth with a balanced lower power setup and seizes would only come if jetted incorrectly.

Fuel starvation is my biggest concern, but only if the engine is pushed through its paces... a pretty solid setup can be achieved no doubt...