Supertrapp setup

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martin846

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Oct 20, 2015
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newhaven
Hi
I have,what I'm told is a Canadian spec (55mph in red) with V Boost imported direct from Japan.
It has 4/2 stock headers running into Supertrapp cans.
Because the bike seemed to be running badly at lower revs.It smells rich and is uneven (but beautifully smooth when the revs rise) , I wondered if the cans were too restrictive as they only have 4 discs.
When I took the end plates off, the discs were underneath and then there was a plate with a hole about 2 cm in diameter with a 10 cm tube pointing into the cans. Having looked at the Supertrapp website I cant see this is mentioned so I wonder if it has been added. The bike is extremely quiet so I am putting in some extra discs.Should I refit this tube arrangement?
Thanks,
Martin
 
8 to 9 discs should be good, that sounds like a spark arrestor.Do you have a photo?
 
Hi
I looked at the video.No sign of what I have.
Not able to send picture at moment but imagine a 4" washer with a 1" hole , with a 3" long pipe over that hole to form a T. The end away from the washer pointing into the can. Seems to me that would greatly increase back pressure from the pressure waves bouncing back towards the engine.
I have ordered some discs and will remove this T , fit more and see how it runs. In the meantime I found the article about blocked jets.I have already used a cleaning additive and carb cleaning spray so suspect the shotgun is required!
Thanks again.
M
 
If the shotgun doesn't do the peashooter is next-https://www.youtube.com/watch?v=xItRzty9_hA
 
Hi
I looked at the video.No sign of what I have.
Not able to send picture at moment but imagine a 4" washer with a 1" hole , with a 3" long pipe over that hole to form a T. The end away from the washer pointing into the can. Seems to me that would greatly increase back pressure from the pressure waves bouncing back towards the engine.
I have ordered some discs and will remove this T , fit more and see how it runs. In the meantime I found the article about blocked jets.I have already used a cleaning additive and carb cleaning spray so suspect the shotgun is required!
Thanks again.
M

Did you try running it with everything off the end to see how it runs ? :ummm:

Dave
 
Hi
I have,what I'm told is a Canadian spec (55mph in red) with V Boost imported direct from Japan.
It has 4/2 stock headers running into Supertrapp cans.
Because the bike seemed to be running badly at lower revs.It smells rich and is uneven (but beautifully smooth when the revs rise) , I wondered if the cans were too restrictive as they only have 4 discs.
When I took the end plates off, the discs were underneath and then there was a plate with a hole about 2 cm in diameter with a 10 cm tube pointing into the cans. Having looked at the Supertrapp website I cant see this is mentioned so I wonder if it has been added. The bike is extremely quiet so I am putting in some extra discs.Should I refit this tube arrangement?
Thanks,
Martin

Mine did the same thing when I put my trapps on.I tried 6 discs first and it ran fine but seemed a little loud after being used to stock exhaust.Then tried 4 and it sounded good but ran like crap.Went to 5 seemed better and ended up settling on 6 after a while.
 
Great video but what is the cleaner and can I get it here?
Can't use the bike at the moment as I started to fit engine bars and some of the fixings are wrong. Hope to get it sorted Monday.
Thanks for the help.
M
 
I finally had the carbs ultrasonically cleaned. Thanks Alfs Worthing.
However although the pick up is better it still runs badly at low revs. It's ok when cold but gets worse as it warms up. At higher revs (2500) it smooths out and thereafter goes like a rocket..
I have 6 discs on the cans and wouldnt want it any louder. It smells of petrol at tickover so I suspect it's too rich.
Alfs set the mixture screws to the factory setting but I wonder if that's wrong for these cans.
Do I screw them in or out to weaken it? Has anyone got ideas please?
Thanks
Martin
 
Thanks for your reply.
If I can't sort it easily,Alfs have a dyno.
Not checked voltage as it starts immediately even with the headlight on ( which I can't turn off).
Once the revs pick up it really flies so I'm convinced it's a carb/ mixture issue.
Ml
 
I finally had the carbs ultrasonically cleaned. Thanks Alfs Worthing.
However although the pick up is better it still runs badly at low revs. It's ok when cold but gets worse as it warms up. At higher revs (2500) it smooths out and thereafter goes like a rocket..
I have 6 discs on the cans and wouldnt want it any louder. It smells of petrol at tickover so I suspect it's too rich.
Alfs set the mixture screws to the factory setting but I wonder if that's wrong for these cans.
Do I screw them in or out to weaken it? Has anyone got ideas please?
Thanks
Martin

Yep it is too rich down low. The reason why it gets worse the warmer the bike gets, is that as CV carbs get warmer, they naturally get richer. There are 2 ways to handle it....one is ok, and the other is the better solution.

The ok solution is to set the mixture screws in just a bit. So, turn the screws all the way in, (to the right until they seat, and please use the proper size screw driver so they dont strip) and then back then off about 2 complete turns. You will need to play around on each cylinder just a bit, and see what it likes, and where the bike runs best. When your running around town 0-4000 rpm, and on 1/8th of the throttle (or so), your just running on the idle mixture screws and that will tell you how the bike is running.

The better solution is actually changing the main jet (easy to do takes about an hour...maybe 1.5 hrs). So the stock jetting of a Vmax is 152'5's.....which is a little bit rich from the factory. So, drop to 150's...or even 147.5's (because you now have slip ons and they flow more air making you richer now.)
 
Hi
I finally got it sorted One of the coils was dodgy so I got a set of COPs from Blaxmax which are fantastic.Plug and play as he said.Will now pull from tickover in top gear.
One warning though.Anything posted to the uk gets charged duty if $50 or over.
Thank yo all so much for your help.
Martin
 
Hi
I finally got it sorted One of the coils was dodgy so I got a set of COPs from Blaxmax which are fantastic.Plug and play as he said.Will now pull from tickover in top gear.
One warning though.Anything posted to the uk gets charged duty if $50 or over.
Thank yo all so much for your help.
Martin
I'll ask members if they want that lessened Martin, Thanks for that info.
Glad to hear it's going well.
 
Hi
I finally got it sorted One of the coils was dodgy so I got a set of COPs from Blaxmax which are fantastic.Plug and play as he said.Will now pull from tickover in top gear.
One warning though.Anything posted to the uk gets charged duty if $50 or over.
Thank yo all so much for your help.
Martin
I had the same issue, one bad front coil.
I switched to COPS and problem solved.
 

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