Whoops

[Fizzyhair]

I bought amotad exhaust to replace the rusted to death stock one. But this 4-1 managed to make my 650 sound like a Nissan micra. Not a great thing. So I drilled out the back baffle with a 1inch hole and now it sounds Epic!! Like a GS should. But at high revs it's not running well it just bogs down and sorta stalls out a bit.

I understand it's probably backpressure but can this be fixed in the input side or have I killed this exhaust?

I have a triumph straight pipe that runs well on the bike but it's far too loud for road use. Sounds like a aircraft is landing on the roof.

[Agemax]

stick the triumph pipe on and go scare some old people. keep the super quiet motad for the 7 day tickets you get from the cops to sort it out lol

[Fizzyhair]

Lol our local police are now pressing a test regulation setting maximum noise at 94db. We are the first uk county it's being trialed in and trust me the triumph can is way above that. I need the motad till they back off a bit as it's an on the spot £500 fine

[Agemax]

Lol our local police are now pressing a test regulation setting maximum noise at 94db. We are the first uk county it's being trialed in and trust me the triumph can is way above that. I need the motad till they back off a bit as it's an on the spot £500 fine

move to plymouth then.£500 fine? we just get a slap on the legs and a ticket to replace it within 7 days

[Fizzyhair]

Yea that's all going away it seams :-(

[koolaid_kid]

Well, you changed the amount of exhaust air that flows (increased it) so you may have to rejet to a larger main (add more fuel) to compensate.

[BassCliff]

Hi,

Well, you changed the amount of exhaust air that flows (increased it) so you may have to rejet to a larger main (add more fuel) to compensate.

Yes, I concur.

A re-jet of your carbs is in order. Read the plugs using "plug chops" to see what the air/fuel mixture is at the different throttle openings. Adjust accordingly.


Thank you for your indulgence,

BassCliff

[Fizzyhair]

It's now backfiring a little at open throttle (exhaust side) what do I do? I understand I need a richer fuel mix but do I need new jets. In which case should I go down the K&N air filter route and have done with it?

[koolaid_kid]

Yes, you need new jets. With just the pipe you could probably get by with larger Mikuni mains.
AFA pods, if you go that route you should go with a DynoJet kit and be done with it.
Pods and a pipe will give you the best performance at the cost of a bit of fuel economy. However, pods are also louder and could suck in a bit of water during a heavy rainstorm (or so I have read). But I have ridden with folk that have a pipe and pods during a torrential rainstorm and they were fine. So, IDK.
My GPz has a pipe and pods and I like both the sound and the performance.
Either way, you will have to do plug chops as BassCliff stated.

[hampshirehog]

If she's pre '83 and has an MOT the coppers can't insist on 94db. If you get stopped ask them how many BSA Gold Stars or Norton singles they are going to have off the road.