4-1 question

[Tompasio]

I just wonder, is it possible that a 4-1 (Marschall Deeptone) can be to tight in the outlet, so it will starve the engine. In the outlet there is a 9mm hole,Can i drill it to be a little larger about 13mm.
-Carbs cleaned (totaly dismantled) all o-rings new
-Valve clearence checked
-Carbs sync ok,with a carbtune instrument
-Fuel level in bowls checked with plastic tube,ok
-Tried to change mains from 120 (original) 122,5-125-130-,up to 140, gets worse with 140
-Tried to raise the needles,one notch
-New airfilter,KN in stock airbox
-Changed petcock
-Cleaned all connections in fusebox
-New wires to battery and ground + extra wire to ground
-New spark wires and caps (NGK)
-Changed the Igniter
-New o-rings in the air-boots
-New 4-1 Marschall Deeptone
She starts very easy,and runs well up to about 100 km/h,then she kinda stalls and wont go any higher or faster,

 

[Steve]

Are you telling us that there is a single 9mm hole for ALL the exhaust to exit through?

If so, I wouldn't even worry about enlarging it to 13mm, I would replace the entire pipe. Most of the 4-into-1 pipes I have seen have holes between 25 and 50mm.

If all you have is that single hole, it's no wonder you can't get over 100 km/hr. :|

.

 

[Tompasio]

At the end of the exhaust there is a backplate,in the center there is a tube about 30mm wide and goes about 150mm down in the exhaust.At the end of the tube there is a 9mm hole and just a couple of mm clerance around the end of the tube.please look at Marshall deeptone at,www.laserexhausts.com

 

[Dave8338]

If that pipe is for your 750, I agree with Steve in that the outlet is WAY too small. Maybe on a moped, but not on a 750cc bike. I too, would be looking for another pipe. Are you sure that they sent you the right pipe?

 

[Tompasio]

Yes it is the exhaust for my GSX 750Es,It fitted without no problem,I will post a few pictures later tonight.

 

[Dave8338]

Hard to tell from the pics though it does look like a quality piece. The exit hole looks to be larger than 9mm (a lot) but again hard to guess from a pic.

Have you run it on the bike yet?

 

[Tompasio]

The hole is a tube about 150mm long,with only a 9mm hole in the other end,I will take pictures of the exhaust end, later tonight.

 

[Tompasio]

Pictures of the exhaust outlet [/attach]

 

[Tompasio]

Pictures on the bike

 

[Detroit Diesel Man]

That looks to be part of the baffle system they use...hard to tell for sure but thats what comes to my mind.

DDM

 

[Mindless]

That looks to be part of the baffle system they use...hard to tell for sure but thats what comes to my mind.

DDM

Agreed.

I'd take the baffle out and check. That doesn't seem right to me. No way a 750cc bike can breathe through that.

 

[Tompasio]

View attachment 9660There are som clerance between the outher tube and the tube with the 9mm hole,I made it white oon the picture

 

[Pete Logan]

Well, that looks very much like my German TUV-approved road 4:1, except that mine does not have the 9mm hole in the middle.

The outer hole is 28mm, and the baffle has no hole, just the gap around it, and it works fine.

I would look elsewhere. Maybe fuel flow