Another A55 build

I picked up a very abused Streetmate for 100.00 and decided to see what I could do with it. I have a weird addiction of making things fast that shouldn't be so I stripped it down and mounted an eBay Honda 125 tank and honda 125 cafe seat. I had to chop 3 to 4 inches from the top of the fuel tank for everything to line up. Cheap drag bars on it and controls from Amazon. Airsal kit, home made intake from 3/4 copper, ktm 50 clone carb running premix. IT had a Tecno Boss pipe on it to begin with but now has. MLM Cali side bleed. Only mods to the kit were a minimal transfer port match, I just angled the airsals ports to match the a55 case. Have the Jammer clutch on 1st and the non cork actual friction material 2nd gear clutch. 27/24 gearing. I weigh 240lbs and iv managed 49 mph on GPS with a slight downhill at 9460 rpm. I'd like to get up in the 50s but I'm not sure what I'll do next. I want to get some more rpm out of it. I planned on raising the exhaust port 1mm, lower intake 1mm and cut 1mm of intake side of piston skirt. Hoping I'll gain some there. I was curious if anything is to be gained by going to mini rotor ignition setup as well. I'll post updates as I have them and if anyone has any advice or suggestions let me know.

Re: Another A55 build

Trying to attach some photos but my phone is being slow. I'll try again tomorrow at the shop

Re: Another A55 build

Sounds like you are on your way! I can’t remember, no way to go 22 on the rear without mods correct? I’m hitting low-mid 40s on an unmodified stock cylinder on my a55 Street mate, decked/shaped head, bullet pipe, high flow vstack w/air box, 26X26 if I remember correctly.

Re: Another A55 build

welcome, we all have the same addiction.

the hpi isnt gonna give u more top speed being lighter. by reducing weight itll give quicker accelleration but pretty much same top speed.

But...if ur running the stock cdi, it may have a rev limiter around 10k. If u have one of those id switch out to an unrestricted one.

Before raising and widening, lowering and widening ports which is a good next step, im curious if you bolt up the tecno boss pipe and detail its performance compared to the mlm sidebleed, top speed/torque, i've had both pipes but have never tested them back to back but as i recollect the cali will have a quicker and wider powerband than the boss.

Testing the boss would also give you a starting point after you port as how much exgaust header to chop off (1in removal equalling 400 rps) to increase the rpms when the power band hits. Also the boss header extends into the pipe which is dumb and youll wanna clean that up

Re: Another A55 build

The MLM pulls much harder and has a 3mph top end gain. Vs the Tecno. As for the ignition being limited iv free revved it well past 10,500 with no break in the ignition. Weight wise the bike is pretty stripped down and I doubt I'm shedding pounds any time soon haha. Going to try and upload pics again.

Re: Another A55 build

Got attachment to work

PXL_20210102_222754894.PORTRAIT.jpg

Re: Another A55 build

One thing I have not done is check the timing and I assume to even change it the trigger would have to be moved, not sure if I'd gain any more rpm under load from the amount the trigger could probably be moved either.

PXL_20210102_222724677.PORTRAIT.jpg

Re: Another A55 build

Overpriced Parts /

5,10 210lb, near or about obese category, stock revival a55, cylinder Large metal mesh filter large size 64 jet, 24tooth rear sprocket, 20mph head wind,

Re: Another A55 build

COOL KEN.

Re: Another A55 build

If you get to the 'm' on tomos that means you're going 55!

Re: Another A55 build

That's a fun looking street mate right there. Nice build my guy.

Re: Another A55 build

Thanks, it looks a lot better with the MLM pipe on it now.

Re: Another A55 build

Does anyone have any suggestions to get more rpm/mph out of this setup besides hooking a rope to it and pulling it behind my truck? LOL Setup is listed on first post. Besides messing with the ports the only thing left I can think of is the ignition. It still has the heavy electric start flywheel on it and I was thinking about getting the HPI mini rotor setup. Thanks everyone

Re: Another A55 build

a lighter flywheel isn't going to help with making more RPMs. an ignition will not get you more RPMs unless the CDI box is limited or it is timed wrong.

I'd suggest getting a flywheel from an earlier model tomos 4-pole CDI, ditching the hall sensor and using a Parmakit CDI box. They are known to be unlimited as far as RPMs go and have a great timing curve.

and even after all that, an unlimited RPMs CDI setup will only net you more RPMs if you are already hitting the rev limiter on the stock setup.

your other options are raising the exhaust port through piston modification or cylinder porting or getting an exhaust pipe with a shorter tuned length.

Re: Another A55 build

Yeah this a55 is a 2003 and I think it's not limited, iv revved it to 10500 on the stand. At 49mph it's 9460 rpm. My plan was to raise the exhaust port and lower the intake port but wanted to make sure I was getting all I could out of current setup. Current pipe is cali side bleed (edited)

Re: Another A55 build

Johnny Braaapp /

Beautiful bike. Nice job with this, wow!

Re: Another A55 build

do one at a time.

in fact, don't even touch your intake port. don't even look at it.

don't even do the porting on the cylinder either, just take down the piston on the crown on the exhaust port side.

this is basically the easiest way to modify port timing without permanent implications. you won't even have to worry about the nikasil chipping.

or do whatever you want, who cares!

Re: Another A55 build

Dont be skeerd, you can go bigly on the exhaust port without ill effects.

Re: Another A55 build

Yeah we grind the crown on our Zenoah RC engines to get more out of them, I'll pull it apart sometime soon and decide what I'm going to start grinding on LOL

Re: Another A55 build

My goal was to get 60 out of this bike, id like to maximize the setup with the 27/24 gearing on it then if I need the 22 or 20 rear gear to get 60 I will.

Re: Another A55 build

Does anyone know if I cut the silencer off a Cali Side bleed if it will hurt performance? I like all my engines loud, I tried taking the packing out then running it with and without the end cap but I feel like the perforated pipe inside the silencer was screwing with the flow with the packing removed.

Re: Another A55 build

Why are you afraid to port?

You’re being ridiculous

Re: Another A55 build

I believe your mis understanding J Bot. No problem with porting, you should read my post more closely. I'm going to change the exhaust port timing. I decided when I built it to just blend the transfers and see how it ran. It's turning 9460 rpms and i was curious if anything else was holding it back In It's current setup. Everyone seems to agree now that raising the exhaust port is the next best thing to do. 👍

Re: Another A55 build

Johnny Braaapp /

This thing is awesome, I’m excited to see what you do with it. Wish you nothing but higher rpm and shredded flip flops bro haha

Re: Another A55 build

LOL thanks, I should show y'all the minibike I built with a 196cc methanol engine on it. 73 mph out of it. I also just built a tillotson 236cc stroker for my daughter's go kart. I own operate a small shop by myself. I repair everything from small engines up to heavy equipment and airplanes. I have a few high hp vehicles but I enjoy the small engines as there not very time and space consuming so I can get a lot done on them with very little time between jobs or in the afternoon.

Re: Another A55 build

its ok..I used to be afraid too

But not anymore

Now I’m chopping ports and smashing transfers and boopin in boosts like they’re going out of style (they aren’t)

Re: Another A55 build

> JBOT Admin Wrote:

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

> “chopping ports and smashing transfers and boopin in boosts like

> they’re going out of style”

I love this. This is a way of life.

Re: Another A55 build

I'll put some pictures up when I get around to changing the port timing so there's more useful information on the airsal a55 setup. I need to get a micro 90 degree die grinder, I currently do not have one small enough to work on any of the ports inside of the cylinder

Re: Another A55 build

Re: Another A55 build

🤣 good stuff, keep it coming

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