Malossi MHR Team 2 Exhaust on a Sport Build?

[jack667]

Hi - 
Here's the question:  Would a Malossi MHR Team 2 Exhaust be OK on a sport build, if it was expected to be run at WOT much of the time?
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Here the rest of the story:
I ordered a Malossi exhaust and now I'm having second thoughts.  I read the thread on 'picking a carb' and that what got me thinking.  It was probably dumb to buy something so expensive without checking with you guys first.  Ugh.

So - I'm building up another Zuma. I bought it with a 'blown engine' which turned out to be 'top end issues'. I bought a Malossi sport 70 bbk kit and put that in and it runs great.  I also put in a UNI filter and NCY Variator that I had laying around. My original plan was to flip it, but now I want to keep it.  Goal - reliable and fast.  Ideal cruise speed is low 50s but high 40s would be ok.  Needs to power up hills.  Probably spending as much time as possible at WOT.  Very similar to my other build, but this is an '05 and the other one is an '08.  

So - after deciding to keep the scoot, I figure it needs some mods.  Exhaust, carb, and then who knows.  I figured I'd get another Dellorto 17.5 carb bc it's a no brainer and I like my other one.  For exhaust, I decided to get a really nice one, and talked myself into spending some major cash.  

After I bought the exhaust I did some more research and see I probably should have bought a Wild Lion or Yasuni R, or something like that.  As much as I appreciate all input, I want to focus on the MHR Team 2 at first, since I ordered and paid for it, and it's in transit.  

Thx!!
Jack

[tsimi]

You sure went all out on the exhaust. That pipe ain't cheap.
As you already mentioned, a Yasuni R or even a simple Tecnigas Next-R pipe would have more than sufficed. The Yasuni R is a sexy looking pipe and would have been my recommendation.

That said, the Malossi pipe you ordered is way too much.
That pipe was made for the Malossi 70cc racing, big bore 77cc/86cc cylinders or something similar in that range. Your cylinder probably won't reach the powerband that THAT pipe needs to fully unfold its power.
I am not even sure if you are able to mount that pipe on a sport cylinder. The flange size and type might be totally different on such high end pipes usually matching the intended cylinder.

It is all about balance between the parts. Cylinder, carb and exhaust need to match. Sometimes it is difficult to tell which part matches what setup but you can always ask here or do some research and check what others have used in the past.

I would try to get in touch with the store you bought the pipe from and ask them if you could return it as soon you receive it. Unused!

[oldgeek]

Your choices I think.

1) Return it/exchange it
2) Build rest of motor to match it. Cylinder, crank, iggy, intake, carb.
3) Port existing cylinder and setup to better match pipe, upgrade crank, and likely carb.
4) Just put it on and likely not be very happy.
5) Save it for a future build
6) Send it to me

[aeroxbud]

In theory you can run just about any pipe with a cylinder. I even knew someone running a stage 6 racing with a stealth pipe and 12mm carb! 😱 The exhaust would work if it fitted. Would it work well though? I would return it if I could. Then buy something more appropriate.

[jack667]

OK - that's great advice and I'll see about sending it back. Thanks for that help.

I'll check with the shop about swapping it out for something more appropriate. Should I try for a Yasuni R, or R07? They seem to be about the same price, and one shop has this description for the R07: "brand new from Yasuni, the R07 exhaust. This guy is one step up from the yasuni R. This pipe is inbetween the R and the C16. Awesome for the guys looking for a quality product, for their sport bore."

Thx again
Jack

[tsimi]

As far i can recall the R07 flange area is made out of many smaller cones giving it a nice look.
Looks very similar to the Yasuni C16.07 aka. City 16

Check pictures here (scroll down a bit)

49ccscoot.proboards.com/thread/15882/yasuni-carrera-16-city?page=3

[aeroxbud]

I suppose it would depend on what cylinder you are going to fit.
Yasuni make Great pipes. I know, I have had a few!
I have just fitted the "R" to my Slider. Even with the standard motor force 50 kit it likes to rev. I guess the 07 will be even more so.

[jack667]

It’s a Malossi Sport 70cc bbk with 10mm pin

[aeroxbud]

The R should go good for with that. This is a dyno graph with the Polini sport with different exhausts. The Malossi is very similar, just a fraction less power. www.pedparts.co.uk/c/asset/sports-pipe-blog/70ccPolini.png

[jack667]

Nov 26, 2018 11:02:32 GMT -5 aeroxbud said:

The R should go good for with that. This is a dyno graph with the Polini sport with different exhausts. The Malossi is very similar, just a fraction less power. www.pedparts.co.uk/c/asset/sports-pipe-blog/70ccPolini.png

That's a nice looking chart for the Yasuni R!  Thx!

[repherence2]

you can always read up about porting and get your Dremel out and raise the height of the exhaust port to about 22-21mm from the top of the bore. Arnadanoob from hondaspree.net says he prefers porting Malossi sport bores because he feels that their port geometry is better than Polini's port geometry. you can port a Polini Contessa into somewhat of a Polini Corsa by raising the exhaust port height. im just thinking that you could port the cylinder to match the effective RPM of that Malossi pipe. Big B NRG blog has a write up on timings and pedparts.co.uk has a write up on "Tuning a Polini 70cc sport cylinder"

[Lucass2T]

Oh man, a 10pin piston and that malossi pipe would mean sudden death. Those 10mm pins are so weak they give out at around 10hp or rpms beyond 10k. Be careful, a yasuni R is as far as you can go power wise. Otherwise you have to swap to a 12mm crank-piston combo.