Triumphrat

19554 · 08-24-2007

Hi Guys, just flogged some old Yamaha bits on e-bay so I have a few quid spare. I am thinking of fitting Mototwin reverse cone silencers, Norman Hyde/Jenks bellmouth, Unifilter, AI removed and pulling the snorkel off my T100.
If anyone out there is running this gear, advice on jetting, shims ect, would be great. Anyone know how loud the pipes are? The cops are a bit keen on pulling really loud bikes around here!

Geoff · 08-24-2007

Use the tuning guide on jenks website to find out how to jet it. Also, most places that sell performance pipes for our bikes will usually have an idea what you need and will provide it, if you tell them what set-up you are running
have fun
G

UK Davesky · 08-24-2007

I am running Morotwin Stainless reverse cones, they come with a pair of 120 main jets which are spot on. I found the pipes work perfectly without any other modifications, didnt even need to alter mixtures or even tickover they just work fine with jet change. They sound great but not too loud [on the mototwin site you can request a sound file by email so you can hear how good they sound] The quality of the finish and welding looks good and with a 10 year guarentee they should last as long as the bike does. They are expensive at £400 but being stainless steel wont rot through in 2 years.
UK Daveski

19554 · 08-25-2007

Quote:

Originally Posted by Geoff

Use the tuning guide on jenks website to find out how to jet it. Also, most places that sell performance pipes for our bikes will usually have an idea what you need and will provide it, if you tell them what set-up you are running
have fun
G

Thanks Geoff, just down loaded the Jenks guide, just about covers every option!
Cheers
gumpt1oo

19554 · 08-25-2007

Quote:

Originally Posted by UK Davesky

I am running Morotwin Stainless reverse cones, they come with a pair of 120 main jets which are spot on. I found the pipes work perfectly without any other modifications, didnt even need to alter mixtures or even tickover they just work fine with jet change. They sound great but not too loud [on the mototwin site you can request a sound file by email so you can hear how good they sound] The quality of the finish and welding looks good and with a 10 year guarentee they should last as long as the bike does. They are expensive at £400 but being stainless steel wont rot through in 2 years.
UK Daveski

Just had a listen to the sound file, they sound like a "proper bonnie"!
I agree they are a bit pricey, but I have heard the Norman Hyde equivalent although a bit cheaper, suffer from rusting!
Cheers
gumpt1oo

UK Davesky · 08-25-2007

gumpt100, I think you will be pleased with them as I am with mine. They look and sound right and I think they are the best on offer in the UK at present. The USA staintunes also look good but the prices [$900] is over the top [plus god knows how much more for shipping,VAT and customs duties]
UK Daveski

UK Davesky · 08-25-2007

I forgot to add that my airbox is standard.
UK Daveski

spiki-spikester · 08-25-2007

I'm running that set up, except I don't have a bellmouth: AI removed, Unifilter, no snorkel, Mototwin reverse cones, 120 jets, no shim, thruxton needles - all on 790 engine.

The pipes went on before I did anything to the airbox & I noticed that once the snorkel was pulled & the Unifilter went in the pipes did get louder under accleration. The carbs also needed the thruxton needles as the stock needles couldn't let the gas through quick enough to mix with the extra air. Once the new needles went in the pick up from 3000 rpm was brilliant instead of sluggish. There's a bit more info on my website, but this is basically all the technical info anyway.

So, advice is to put thruxton needles in if you are going to run that set up.

As for noise it is perfectly ok and civilised up to 3500 / 4000, but gets pretty loud after that. But it isn't anti-social, its an old fashioned bike sound. I had the misfortune to get pulled over a few months ago (I got an SP30 for my trouble) and had the engine up at 5000/ 6000 rpm - in the loud range - but the nice policeman didn't say anything about the pipes at all even though he gave the bike a once over to see if there was anything else to do me for. Can't speak for the police up in Cumbia though !

19554 · 08-26-2007

Quote:

Originally Posted by spiki-spikester

I'm running that set up, except I don't have a bellmouth: AI removed, Unifilter, no snorkel, Mototwin reverse cones, 120 jets, no shim, thruxton needles - all on 790 engine.

The pipes went on before I did anything to the airbox & I noticed that once the snorkel was pulled & the Unifilter went in the pipes did get louder under accleration. The carbs also needed the thruxton needles as the stock needles couldn't let the gas through quick enough to mix with the extra air. Once the new needles went in the pick up from 3000 rpm was brilliant instead of sluggish. There's a bit more info on my website, but this is basically all the technical info anyway.

So, advice is to put thruxton needles in if you are going to run that set up.

As for noise it is perfectly ok and civilised up to 3500 / 4000, but gets pretty loud after that. But it isn't anti-social, its an old fashioned bike sound. I had the misfortune to get pulled over a few months ago (I got an SP30 for my trouble) and had the engine up at 5000/ 6000 rpm - in the loud range - but the nice policeman didn't say anything about the pipes at all even though he gave the bike a once over to see if there was anything else to do me for. Can't speak for the police up in Cumbia though !

Just visited your site, good info, and lots of ideas for spending more cash!
gumpt1oo.