Best carb for 70cc kit on Tomos a55 Streetmate?

I currently have a Dellorto 17.5mm PHVA carb with tuned needles and jets. I'm about to have a 70cc kit installed on it and am wondering if I should switch to a PHBG carb. If that makes sense, should I go with a 19mm or 21mm?

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

bump

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Probably Fred /

Stock intake is only 15mm

So unless you got a different intake any carbs you put on there will only be a 15 mm carburetor

So stock 14 phva or 17.5 phva

If they made a 15mm phva it would be best

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

A 17.5 phva can handle a lot.

Hell I put a 14.5 phva on my bombardier 50cc quad and I can rip wheelies on it and top out at 35~

It's a 70cc tomos kit. If it's an airsal. It's gonna hit an rpm brick wall with torque for days.Tune with that 14.5 with a nice flowy filter and just regear accordingly.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Harris Brancazio /

Hey man, I have a 70cc head, biturbo exhaust and 17.5 carb. You have any idea what jet and mixture sarew settings I should use? Can't find any info on the web. Thanks man!

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Brandon Weiss (Detective brandon to you) /

> Harris Brancazio Wrote:

> -------------------------------------------------------

> Hey man, I have a 70cc head, biturbo exhaust and 17.5 carb. You have any

> idea what jet and mixture sarew settings I should use? Can't find any

> info on the web. Thanks man!

anywhere from an 80-85 main jet, 30 ish idle jet.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Harris Brancazio /

I currently have a 25 idle and 95 main, cant get it to run at all for the life of me. are my jets far off enough that this makes sense? also I am running a 45 choke jet this okay? and any air filter suggestions?

thanks a ton!

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

the mlm a55 intake with phbj 19 is a fun setup the sound worth the price u can run wot forever . i run a55 with a35 airsal gutted 4 pedal with phbg 28 20 gearing a35 cdi wicked curve box

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Brandon Weiss (Detective brandon to you) /

> fred sams Wrote:

> -------------------------------------------------------

> the mlm a55 intake with phbj 19 is a fun setup the sound worth the price

> u can run wot forever . i run a55 with a35 airsal gutted 4 pedal with

> phbg 28 20 gearing a35 cdi wicked curve box

What kinda speeds do you get?

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

tops out about 54 first gear wicked quick when you kick it it goes

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

> fred sams Wrote:

> -------------------------------------------------------

> the mlm a55 intake with phbj 19 is a fun setup the sound worth the price

> u can run wot forever . i run a55 with a35 airsal gutted 4 pedal with

> phbg 28 20 gearing a35 cdi wicked curve box

that is an A35 setup though, by the way dude is talking, he's gonna run the A55 airsal kit.

stock intake and 17 phva is a good setup on that kit, you might get a lil' more top end off the 19 or 21 phbg and aftermarket intake but for my dollar its not worth the extra 150-160 bucks.

If i was going for a higher end build like that, i'd build with an A35 kit, if you gotta buy carb and intake anyhow, you're money ahead going for a Parmakit

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Brandon Weiss (Detective brandon to you) /

> fred sams Wrote:

> -------------------------------------------------------

> tops out about 54 first gear wicked quick when you kick it it goes

Really? I'm hitting 52 with 26x22 sprockets, the bone stock a55 ignition, unported a55 44mm airsal, estoril side bleed, and a home made intake with a 17.5 phva clone. Seems like you're geared way too far out to me.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

I'm using a 21mm PWK, but the intake isn't stock.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Alan Jackson /

does a long intake like that work best at lower revs ?

or is intake tuned length not as big a thing as exhaust length?

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Probably Fred /

> B 440 Wrote:

> -------------------------------------------------------

> I'm using a 21mm PWK, but the intake isn't stock.

>

> https://lh3.googleusercontent.com/32-3tAuWyVPeGzke8KOJUQKsycLgafqtfnAN8onQIVHbXAoT_yEht0QxEPVFK37q3oNTEA6HcLMiuY14671VUmJFnz9eTG2oa6-HuDcJhKQYTSIkh3x24OnYn0LUVgWbGadcQpRxpj3DEeW6WEuye1yJLm4k31e_eprjjNn6FTgCet3wbvzyGj7fhTzme9eMIqeAhgTV6JG6YTsF268QFVc0lu_FFQHob-kkeotIHd5cH4ObpCIwiQKVjtDbbJ-hdq9E-ZYSwXtZwvm6zsWzGf9k5nLOm7GtezzUkAVVHZNy2Jubj-6q3nwIBzZUM6Y9ESyhaKPX4YngERx3Wrc9sf0BtnP1jMV7-COe1lz0jCGelyRLLuMaOqAsadNlbHy9DxuiIvMmq68OYAx45bI5u9BXERgM2lz_3RF-8QjdC-brhdrKoQbiWpW7ikQn1qfoZDz3_m2lsgfqyn6imMUKDxGdHQfJslNa6UX9dm7crbZuj3iO8-kKIhQ6tqnGQuh3hOFVMFWgVxuOCii1WaPwx5ADDi6rPEp1fg_OORWKF7Bz3LZibbl6DREQTAx0k0CkofuZJBDdcKI1orGHvYKVkCyg0L17Yv36JbJpPqc_c8EnwYNINj6eSXQnJAaOzdgwjBxwJ2zOtW7exsz-3FH-GmEG=w886-h664-no

>

> https://lh3.googleusercontent.com/y4iO5GDhvSRmtia07p8op-qiHevZeHWPzlFv3dPNTgIIDWbn-8oYjiizT73rrunwbqLKvXYmqFlCwVIoFekwJhXavLhnXiOxlDi0S-a_4PAu8jQ7kZvO1NP5ilJuTKzEYqOVe27BqPgTL-CuuSJUZoh5nt2ZGNGEqT-T59P2Vz616hNjGpammeHxr8BQeqQF3vHxzPNDoDAuOLW-7DobslLoy-d1YQP1MJmxZKMM78q06ySzsyekm6YTfKru-_E4qT1AojFpxQPGj15qYkm_oAZitrGdnHgyRhMyGAkw8bpQNoW_Cf-ngpwwxjaxbtCKP-JChPuUx-LcaNyBVpNxLFI6lFrAVyocBEoB2CjWZlfAANDImq9Wm4QBWaC5A4bQIg62TL_icmuWeprpTg_E8XVbVjFSFxmueKwgmUCjoH5dPP3Ty2GE_HcIAtYc1E5Wy0PzQqdQbrFpDF137eSxdpn7UAGldshlmxupuC7OriUdmI2IiIACmNvvUsiEWs-Aj6TMPha4IrZ-EUVA5DoIZmjnK1AFaPLDpdGtAINcRTB_OFfcpBHZK2jJRgGmEPwMqQMwUebGFcYvIOyD2n6jd7uLE9apqVnVJlAg5OJFzU-EHQAs1LXU3cDD6LuRu-Dk6S1FboTnblJcGoNYT1x7n8jF=w886-h664-no

>

> https://lh3.googleusercontent.com/7VSHoGvxXG8lJuKDee3VkFLE01GVs1K3mUY4fNA-RxTTISfKXrLwCQ1jgqBSyWgLtM7wi7Fju62tHQe_6VV64ro_EQ7odQwZjTxWtaUK4tcZn3iT-lstWZwOpzaZx7sWodIwZEocm2LP0pOx1qe88QJQDOD5_uC4-tu_Msf3bfNmcFPqyQ1Q4rppMFFfJ0yLW9GVEElV4GVyBqxdqIq7cUl5reclpZN0d5oV0VB55dH5qOXO--VBrjklJCKnqGs2uaa5GttiqxsaoRhOCuTa8H-NzEfzpb36rO0VZS0WV1KzfoAgG2Wr-VP4-wIrH4-i71n7aRRiajog2foES_95aWU-k1uJzXsbsi_RE6arzpPkOvU89aFH6lcYFXuCwXZV7zJBJTGn0d5osHcrsJYfiw4pAOe39M3YB2jOyLq71jSGzDMa09ZZd0NHf_jPX2l18jFjHSZvEQaWa1tcHFvTAnbroKrR013N8j6Z5qT7sfsPZdXk2ga5z5rCqEilSvOFpZJpEh98zwdNW9gDLV55XxtiXgg1FtXgAlrBIrTAarUZ0sXg0fzju_2oTBmJDPWJDKbpnZlvqVoU1yquVZ5T0CtMxd8w9O1Cwg6H5ZHMXV9Igk9hx5SMcz7N6iRhI2Qr_vfyX7pjsBNpo4y0wOR32Dl9=w886-h664-no

Lose that horrible double foam filter and get a 13$ mesh type for more consistent jetting/tuning

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

> Ken Roff Wrote:

> Lose that horrible double foam filter and get a 13$ mesh type for more

> consistent jetting/tuning

HAHA

i like that the takeaway from this is that the foam filter is the problem....

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Alan Jackson /

I was running no air filter (till one arrived through the post today!!!) and just for a laugh I thought i'd try making one out of a car wash sponge

it ran awful, far too restrictive

who knows where some of the pod manufacturers source their sponge from?

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

The length of the intake will have some effect, not as much as the exhaust. I just needed to get the carb to clear the engine/frame.

Agree that any filter attached directly to the carb will make problems jetting properly. The goal is to get the filter up into the dead space of the faux tank. For initial tuning I might just use a length of PVC pipe between the carb and filter so the incoming air is less turbulent.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

This old thread is close to something I am trying to understand about upgrading a 2007 Tomos Streetmate. I am trying to learn, from all available threads, on all applicable websites, how to get the better hill performance from my Tomos. I live in San Francisco, CA. I bought my Tomos from a neighbor, around the corner. He was asking $100.00.

I thought this was a lot of bike for $100.00. I gave him cash and walked it home.

20191203_113427.jpg

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

25x22 more torque or stock 26x22

Put a kit on high compression head

Porting case matching

Better exhaust better carb

Look in the wiki for more info about performance. (edited)

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Looks like you got the deal of a lifetime .

I hear the dirt in the tire treads is worth a hundred bucks there . ;)

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

Well, perhaps the deal of the year, but really, unless I can get it to run well, it is just a course in learning about carburetors, and how to tune them. I have taken this bike and got it to run fairly well with the stock 55 cc setup, with the upgraded exhaust biturbo. I replaced the stock 15 mm dellorto carburetor with a new Dellorto 15mm one. I tuned it. I was running around perfectly fine at 30 mph on the flats, and sometimes 15 mph on the hills, sometimes less.

I thought to myself, what in the world do I want with a moped that can barely do 15 mph on the moderate hills of San Francisco. I will be pushing it up the steep hills, and better to dump this bike.

Then I decided to think outside the box, as so many moped owners do, and see if I can modify this little beauty to work in San Francisco.

This means more power!

So I installed a new Airsal 70cc kit and new Dellorto PVHA 17.5 mm carburetor.

This is the introduction to the beginning of the journey.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Harris Brancazio /

I have basically the exact same engine setup, how is it running for you?

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

> Russell Murphy Wrote:

> -------------------------------------------------------

> This is the introduction to the beginning of the journey.

Excellent attitude . ;)

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

Not good. That is why I am reaching out in this forum. I have currently a 76 main jet and 34 pilot jet. Needle is set at position # 4, so on the very rich side. ( Position #1 is top, and #5 is bottom. Top clip position is lean, bottom is rich. I started with an 86 main jet, which it came with, and worked my way down to a 76.

Main 76

Pilot 34

needle #4 position,

Starts well on choke, turn off choke and revs well and dies down quickly, but no power from 1/4 to 1/2 and nothing better.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

Thank you for saying.

Yes, these are the days that no one will bother to work on the 2 stroke moped. Apparently there is no money to be made in keeping these bikes running, it is trickey, and everyone has moved onto the 4 stroke. Very Understandable. Tuning carburetors on a 2 stroke will be a lost knowledge, because those that know can't be bothered to teach others, because there is no money in teaching.

How did this world become so much about money, and so little about knowledge?

Well, I implore anyone with knowledge about 2 stroke mopeds, to please share your knowledge on this thread.

All experience and wisdom is welcomed

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Harris Brancazio /

I wish I could help you more, mine runs like serious dog shit. It starts no choke first kick every time but has a high idle and won't start hot. My jetting is definitely too rich, but I also suspect my stock 15mm intake is richening up the mixture as it's not letting in enough air and I think the tight bends cause a build-up and sudden release of extra fuel. I'm going to solder a 3/4 inch copper intake this weekend and I can report back to you then. After that, I suspect significant jetting and plug chops will be necessary.

-Harris

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

My setup:

Tomos Streetmate A55, made in 2007.

Installed new Airsal 70 cc head cylinder and piston, (large bore upgrade)

Replaced 15 mm Dellorto Carb with new 17.5 Dellorto Carb.

Neddle clip rich, #4 position. Pilot jet at #34.

Starts, runs and goes, like a piece of shit.

Started with a 90 main jet (which the carb came with) and worked downward.

I have read everyones forums and blogs and watched youtubes.

For 3 months.

Jet by jet, needle by needle, clip position by clip position, custom air filter, custom intake for new 17.5 carb. Still, it just runs like shit, no guts, no fun.

I won't despair, I will persevere, but if anyone out there has some knowledge, please share. I have jets and needles and time and patience. I am trying many things, changing one component at a time, still, this should be a science, to some degree.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Russell Murphy /

Yes, I think you are on the right track. I am a bit ahead of you, as I already soldered the 3/4" copper to reflect the original 15mm intake set up. My intake, made from 3/4: copper is now 18mm. This, I thought would work well. I believe this is not the issue for the power loss on the bike, but I welcome others to hear their 2 cents.

Re: Best carb for 70cc kit on Tomos a55 Streetmate?

Harris Brancazio /

Ah shit, looks like we might be fighting the same uphill battle then. What do you run for an air filter?

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

Login or Create Account