Tell me why I suck

So here’s the build, but I’m only consistently hitting about 37-38mph (GPS app). Based on others people posted builds and top speeds, I feel like I’m missing something here. I’ve recently been in the engine and all parts are in good working condition, transmission fluid is good and at proper levels.

99’ Tomos a35 Sprint

Puch 50cc HiHi Head

Boyeson 2 stage reeds

MLM 15mm intake

Dellorto SHA 15.15 (68 jet)

Hunter Exhaust

26/22 gearing

Timing moved to about 3/4 down from top mark (was directly on top mark as stock)

Before moving timing I was hitting second gear right around 20-22 mph, now it’s more around 16-19mph.

0-30mph in about 10-11 seconds

Excel sheet of my personal tests against saved tests in link below (all of these were taken before adjusting timing). The numbers under “My Tests” are mine (all checked by the same GPS on the same road). Under “Tomos” are the ones on file in Moped Army.

https://docs.google.com/file/d/1U2Qf0oqrpmXfbARFU3x4vYEuj6U3UHkw/edit?usp=docslist_api&filetype=msexcel

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Re: Tell me why I suck

Overpriced Parts /

Goofy looking milk crate that’s why !

Re: Tell me why I suck

Timing change sounds like it hurt you? Usually the later you shift means you're making more power.

That speed sounds about right without a little porting. Chain, wheel bearings, tires, brakes, all can factor in as well. Make sure your carb is opening all the way, make sure your tune is dead on.

Re: Tell me why I suck

Timing change seems like it’s letting me hit the pipe at higher rpms and giving me my top speed a little easier, but seems like I lost some torque lower down.

Also helped a hanging idle issue that the boyeson reeds had caused

Here’s where I have it, stock it was on the middle on the top line. (edited)

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Re: Tell me why I suck

Hi hi is too high I’ve found

Re: Tell me why I suck

That ten foot long, kinked header pipe on your chamber might slow you down a bit.

Re: Tell me why I suck

> baird co Wrote:

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

> That ten foot long, kinked header pipe on your chamber might slow you

> down a bit.

People have had decent results with this pipe before. I have a good old Biturbo and a circuit pipe I could try out as well but I’m trying to stick to the hunter because of its left side novelty and awesome matching 90s stickers (and my gf is gonna kill me if I swap it)

I’ll try the others and see if I find results. Anyone else hate the Hunter pipes?

https://www.treatland.tv/tomos-A35-hunter-black-exhaust-pipe-p/tomos-black-hunter.htm (edited)

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Re: Tell me why I suck

Try the circuit pipe for a day and see what happens. That Hunter pipe shape goes against everything I've ever learned and experienced with pipes.

Re: Tell me why I suck

Overpriced Parts /

> baird co Wrote:

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

> Try the circuit pipe for a day and see what happens. That Hunter pipe

> shape goes against everything I've ever learned and experienced with

> pipes.

It could have a restrictor in it too

Re: Tell me why I suck

Well, if you are really hitting 38mph on a stock tomos w no porting and just bolt ons thats pretty darn good.

Anyone telling you otherwise is BS, reading their stock speedo, not verifying with a gps or weigh 10 lbs.

Like Gram said put timing where it lets you shift later equalling more power. Do you use a timing gun?Consult timing in wiki. To address the loss of low end torque add a stiffer spring to first gear. I am guessing some has changed out 2nd gear spring already since it shifts at 20 instead of the stock 10 or so.

Are you running an air filter? air filters affect jetting quite a bit on sha carbs, running a stock unmodded box filter changes jetting.

I've had a similar bike a35 sprint with milk crate, black paint, 26/22 gears, opened up stock intake, black cap w two mesh screens, i believe red first and yellow second gear springs, circuit pipe. It was a fun, bike accerated nice, top speed just under 40 is my guess, i weigh 220lbs. A good speed is when my helmet starts to lift from the wind speed hitting my little sun visor and starts lifting the whole helmet up.

Re: Tell me why I suck

> pat splat Wrote:

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

> Well, if you are really hitting 38mph on a stock tomos w no porting and

> just bolt ons thats pretty darn good.

>

> Anyone telling you otherwise is BS, reading their stock speedo, not

> verifying with a gps or weigh 10 lbs.

this. most people are lying about their 45mph stock top end tomos

Re: Tell me why I suck

Yeah I dunno what the deal is with the tecno hunter, I've seen some bikes rip with it but it defies all logic. I keep a boss/biturbo around for gut checking builds, that would maybe be my next step if you really think it's leaving something on the table.

Like others have said, without porting you're really not gonna go much faster if 38 is your real flat ground gps speed. Most tomos lovers lie like crazy about their top speed.

Also what jbot said, you'll get a higher top speed with lower compression and more advanced timing. You'll get more torque with more compression.

Seriously though, I'd get out the dremel and open up that exhaust port, it's stupid not to, I don't even know how fast a stock a35 is supposed to go since I always port them first thing.

Re: Tell me why I suck

Dirty30 Dillon /

> Graham Motzing Wrote:

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

> Most tomos lovers lie like crazy about their top speed.

Re: Tell me why I suck

> pat splat Wrote:

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

> Well, if you are really hitting 38mph on a stock tomos w no porting and just bolt ons thats pretty darn good

> Anyone telling you otherwise is BS, reading their stock speedo, not verifying with a gps or weigh 10 lbs.

>

> Do you use a timing gun?Consult timing in wiki.

>

> I am guessing some has changed out 2nd gear spring already since it shifts at 20 instead of the stock 10 or so.

>

> Are you running an air filter? air filters affect jetting quite a bit on sha carbs, running a stock unmodded box filter changes jetting.

>

>A good speed is when my helmet starts to lift from the wind speed hitting my little sun visor and starts lifting the whole helmet up.

Just bolt on, no porting yet. I guess that’s my next step there.

No timing gun, just trial and error atm.

Stock gear springs, 1st and 2nd (got the bike basically new). I noticed it holding first longer after the reeds and head went on

Figured there might be some fibbing going on with the top speeds

Small aftermarket air box (drilled out) with velocity stack incorporated and panty hose filter material (pictured below). I was running just the velocity stack but it seemed the air box gave it more consistency and back pressure

And that’s funny about the helmet, I judge the same way 🤣🤣 (edited)

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Re: Tell me why I suck

> Graham Motzing Wrote:

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

> Yeah I dunno what the deal is with the tecno hunter, I've seen some

> bikes rip with it but it defies all logic. I keep a boss/biturbo around

> for gut checking builds, that would maybe be my next step if you really

> think it's leaving something on the table.

>

> Like others have said, without porting you're really not gonna go much

> faster if 38 is your real flat ground gps speed. Most tomos lovers lie

> like crazy about their top speed.

>

> Also what jbot said, you'll get a higher top speed with lower

> compression and more advanced timing. You'll get more torque with more

> compression.

>

> Seriously though, I'd get out the dremel and open up that exhaust port,

> it's stupid not to, I don't even know how fast a stock a35 is supposed

> to go since I always port them first thing.

How difficult is the porting (never attempted one)

Also, would switching out the hicomp head for a stock one possibly remove some torque but push the top speed?

Trying to get to a consistent 40mph on the 50cc. That’s been my goal with this build

Re: Tell me why I suck

There’s so much power available in your cyl.

Look up my cyl reed porting threads.

Copy what you see.

Big piston window, big boost, wider ex by a few mm each side, raise exhaust a few mm.

You’ll be ripping dicks

Re: Tell me why I suck

you need to get all the stuff the clutch side of that pedal shaft first.

38mph with a stock a35 top end and a hunter pipe is great. it's what I am getting out of a bike that i've built for a customer, GPS bike speedo verified. I'm geared at 26x22 on a 2.25" Mitas B8 tire.

I'm using a stock tomos cylinder head and the stock tomos airbox and intake and oil injection, too.

38mph is right where you should be. I would say get a stock a35 cylinder head and adjust your timing back to where it was and blast.

if you have a timing light and a dial gauge indicator, you could figure out exactly what your timing is set at, instead of just moving the stator. I'm like 99% sure that cdi will have a timing curve, which is pretty cool, but the only way you'll know is with a timing light!

Re: Tell me why I suck

there is actually some good tomos info on this thread, congrats!

I would agree with Jbot that the hi-hi is a bit much, Id swap to the stock head with out a head gasket

and yes as stated 38 is good on a stock a35 cylinder! Honestly i usually get 36-40mph with a biturbo, the small difference really comes from the condition of your rings, so dont stress about it while your top end is completely stock

Also anyone complaining about the Hunter pipe has clearly never ran one, they hit like a circuit then carry like a larger pipe, you wont find anything better unless you get into the more expensive pipes!

Re: Tell me why I suck

Consensus confirmed, moving right along... That air box does not have "built in velocity stacks". Those are two plastic dodads that reduce intake noise and further restrict air flow, pull those out, drill a few more holes, remove a coupla screens on the metal mesh filter, drill a tiny hole to let gas drain out on the bottom of the box and turn the damn box away from your sidecover. Now save those plastic spacer things to use later, good for sidecovers, spacing stuff out,like mounting license plate without scratching, etc.

Read up on porting cylinder to go faster. Read up on how to dress you cylinder and stock head for a good seal.

Re: Tell me why I suck

so ok....on my 64cc airsal kitted a35, I run a 15:15sha with that same intake and airbox. I use the metal mesh element that comes with the SHA and the airbox with the plugs removed and the bike runs great.

As far as those boyesen reeds go, I always thought they were kind of gimmicky. I really like the stock Airsal Reeds, the rubberized Athena Reeds or the Doppler ER2 reeds. I'm running the ER2's right now and it added some performance i think? It felt peppier, but I also upjetted for colder temps/the new reeds at the same time so like who really knows?

anyways, I wouldn't go drilling anymore holes for flow or gas drainage, but you should move it away from the side cover, unless you have that portion of the side cover cut away. If that portion of the side cover is cut away, I think the position of the airbox is actually pretty optimal (and exactly the same position that i run mine in.)

also, I would make sure everything is good with the rolling frame before doing any cylinder porting. We've got some spare a35 cylinders, pistons and stock heads here that I would sell if you wanted to give porting a shot without having to port your good cylinder.

Re: Tell me why I suck

Jack Rutherford /

The Tomos is so intriguing.

Re: Tell me why I suck

> pat splat Wrote:

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

> Consensus confirmed, moving right along... That air box does not have

> "built in velocity stacks". Those are two plastic dodads that reduce

> intake noise and further restrict air flow, pull those out, drill a few

> more holes, remove a coupla screens on the metal mesh filter, drill a

> tiny hole to let gas drain out on the bottom of the box and turn the

> damn box away from your sidecover. Now save those plastic spacer things

> to use later, good for sidecovers, spacing stuff out,like mounting

> license plate without scratching, etc.

The velocity stack is a 3D printed one that I’ve installed between the airbox and carb. I keep panty hose on it atm, but I’m thinking of moving the filter material to around the airbox now that it seems like it will stay. The stack keeps the gas carb side as well which is nice. All screens have been removed. (Pictures with the filter removed)

The boyeson reeds might of actually dipped my top speed just a tad, but they make the bike so much peppier and responsive. Nearly eliminates that Tomos throttle drag IMO.

My consensus is that I will swap in my stock revival head with no gasket and see what results I yield. If I still am not seeing the results I want I might switch over to these carbon reeds from treats

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Re: Tell me why I suck

Ohh, and the side panels have all been appropriately cut.there’s plenty of clearance and I can still put my feet up when feeling frisky

Not the best pic, but here’s an old setup

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Re: Tell me why I suck

oops, fancy hidden velocity stack id still pop out those plastic do dads. , how does it run with just the velocity stack and panty hose?

Re: Tell me why I suck

> pat splat Wrote:

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

> oops, fancy hidden velocity stack id still pop out those plastic do

> dads. , how does it run with just the velocity stack and panty hose?

About the same, after about 35 it was feeling like it couldn’t suck because of the wind passing it so I down jetted just a bit and slapped the airbox on (with a bunch a holes added) and I went from 38-39 tops to 37-38. The acceleration at the higher RPMS feels much better though along with the idle being more consistent and the sound being much lower

Biggest benefit without the airbox was top speed and responsiveness at lower RPMs

Re: Tell me why I suck

Thats what i figured, with less restriction on airflow you will up the jet a coupla sizes. With restriction aka air box, silencer tubes down a coupla sizes. A nice thing to have while tuning is a cylinder temp gauge or a temp gun if you can find one.

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