New sports exhaust not working properly on moped!

[Jackhobbs]

Hi, I have just fitted a new technigas next r exhaust on my Yamaha aerox yq50 2008, however there is a problem with it when I pull yaw throttle back the bike doesn't react with it it goes about 10-20mph for around about 15-20 secs and then it just suddenly pulls away, but them when I slow down it repeats the same process I have took the air filter out and cleaned it but it hasn't made a difference any ideas?

[G]

Your bike was designed to run with the original exhaust.

If this exhaust is actually substantially different (a lot of the time 'sports' just means louder), you're going to have to set the fueling up to run with the exhaust.

This isn't a computer game where you just bolt on a component and gain 20% power, I'm afraid .

You may still find that if the exhaust is made for top end power, the bike doesn't make as much power lower down.

[_Iain_]

Try +2 or +4 on the main to get you started & then plug chop it. Most scoots only need to go up one or two mind.

Check that you removed the inlet restrictor - Tecnigas & Viper supply all their exhausts with a restrictor washer still installed, screwdriver it out.

Think the rollers you need are 15x12 4.75 gram, or thereabouts as thats what Viper reccomend with their pipes. You'll probbably go to 4.5 without any issues mind if you're a skinny 16 year old.

HTH
____________________
Please be aware that the above post may be full of complete nonsense.
Riding: '07 KTM Duke II, Baotian BT49QT-20 Driving: '88 Volvo 340

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[Jackhobbs]

Okay thanks for the help I've order up a roller set that has between 4-5g rollers and a carb main jet set between 60-80 so hopefully I should figure out a good tune from these thanks for the help.

[gavcarter]

These pipes are made to develop all the power up top and rev like crackers.

You will probably need ( after jetting correctly) to lighten the rollers and get heavier clutch springs ( and your bike will bike sound shite...)
To get the best out of exhaust like these you need the rollers, clutch and variator set up to keep the engine where it makes most of the power and the gearing is what accelerates you not the engine revs.

So when its all done and dusted your poor little scoot will rev its tits off from the moment you set off until you come to a stop....

[_Iain_]

[gavcarter]

[G]

As above - jetting, then rollers to suit.

You'll be unlikely to get optimal results without some dyno time, but should get it more usable.