Riddling out a pipe that didn't work. MLM

Dave Thacker /

Oct 17, 2020 04:43PM

Bought MLM A55 pipe: https://www.treatland.tv/MLM-tomos-A55-people-s-sidebleed-pipe-p/mlm-tomos-pipe-355.htm

I have another A55 on a Black Pipe. I wanted t try something different. So I purchased the MLM pipe to replace this Bi-Turbo (I hate how it sounded). Mounted it up. I am running 60 jet on stock 14mm Delorto Carb. Bike would run about 37 indicated on the Bi-Trubo. I inspected the piston, no sign of any sticks. 3700 miles. Stock bore cly and head.

I ran the MLM pipe on many jets from 58 to 70. Couldn't get more than 35 indicated out of it. Changed it back to the Bi-Trubo as it sits now.

The MLM just never seemed to respond to jet changes. I never felt it clearly come on the pipe. It essentially ran the same up to about 35 on every jet. The smaller the jet the more peppy on the low end. On the 70 it was very obviously slipping in and out of 4 stroke at top speed.

What am I doing wrong? Was this just a poor choice in a higher end pipe?

I've replaced the Bit-Turbo on 2 other Tomos (and A55 and A35) and always got a little something better out of them after turning.

Re: Riddling out a pipe that didn't work. MLM

Jack Rutherford /

churioz

Oct 17, 2020 06:17PM

Put a tach on it and see what rpm your biturbo starts to hit at. The mlm probably hits at a higher rpm and you’re just under it. Or get a little help from gravity to boost your rpms and see if it will hit. (edited)

Re: Riddling out a pipe that didn't work. MLM

Jay Rivett /

bjaockx

Oct 17, 2020 08:31PM

What is your gearing at? The side bleed probably got you to 35 a lot faster than the biturbo. The side bleed is going to hit a wall more than the biturbo will. It is a low mid range pipe not a high speed pipe. If you need the more speedier version you would want the non side bleed version of the peoples pipe.

You can add a larger sprocket up front and go a little smaller in back. Tomos is fun with an almost 1:1 ratio for the gearing. You will lose some off your low end but will gain more top for sure.

Re: Riddling out a pipe that didn't work. MLM

Dave Thacker /

crafted OP

Oct 17, 2020 09:16PM

Jay, I'm running 27 front, 20 rear. I live in a very flat area and am not looking for a hill climber. I do have a 28 rear I removed from another bike. This particular A55 is very punchy off the start with both pipes. The MLM isn't any better anywhere in the RPM band really. I think I may offer it for sale. Not the pipe for me from your description which I respect. I've ran it down a hill. I could find a steeper one and try again. But then I'd have to put it back on. I had to remount he Bi-Turbo just to prove to myself the engine was better than what I was getting. I want a pipe that comes on like the Estoril does on the A35. She looked good before the date. If there is no way to make her come alive, she's for somebody who finds a doll a move up.

Re: Riddling out a pipe that didn't work. MLM

Jay Rivett /

bjaockx

Oct 17, 2020 11:47PM

You are definitely geared for speed. Anything bigger in the front requires some case mods. And not gonna get any smaller in the rear. Sell the pipe and see about a cranks pipe. You gotta get your name on a waiting list so dont expect a quick turnaround.

Re: Riddling out a pipe that didn't work. MLM

Graham Motzing /

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grahammotzing

Oct 18, 2020 12:21AM

your bike is barely breaking 6000 rpm? and you're wondering about a pipe?

none of those pipes are even in the equation at 6000 rpm. biturbo doesn't hit until like 8k, and i dunno about people's but probably similar.

you are better off welding on a lawnmower muffler at this point. you need to gear way way down, like 26x22 would be a good starting place. and maybe even down from there, I usually run 26x24 on stock/ported tomos which puts you at like 9500 at 45 which is going to be your top speed gearing/ peak power.

I haven't heard great things about the people's pipe but if you do some decent porting, gear right, and even run a biturbo, you should be over 40 with good acceleration, and it doesn't take much porting and a PHVA17 to get you over 45. Piston ports in general just don't like to be loaded up on the bottom end, if you don't let them rev enough to clear out, they won't make enough power to dig out of the hole. That's another place where some second gear clutch tuning can help a lot by letting it hold 1st longer so its already closer to the powerband when second grabs.

Re: Riddling out a pipe that didn't work. MLM

A Fouler Fowler /

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fowler

Oct 18, 2020 09:11AM

A55 should easily break 45mph with a biturbo (as indicated by speedometer, not gps) I think you are geared to high, you wanna get your rpm peak arround 45mph, which is like 10k rpms if you are tuned well.

I had a technigas next that wouldn't push an A55 over 40, but it would do wheelies.

The following assumes tomos sprint wheels (Not revival/streetmate)

This is 27x20

This is 27x24

27x25 gets the rpms up to 10k at 45

Re: Riddling out a pipe that didn't work. MLM

Jack Rutherford /

churioz

Oct 18, 2020 09:27PM

Yep. Ain’t nothing hitting at 6500 rpm.

Re: Riddling out a pipe that didn't work. MLM

pat splat /

ggspeed

Oct 21, 2020 11:03AM

yeah, time to dremel and breath some aluminum dust...

, wait what was i doing.

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