Running rich due to exhaust mod?

[Thevmaxrider]

OK so now it makes sense. Smaller jets just allow the same amount of fuel through as stock because it's being pumped harder by the more open exhaust.

Blimey that took some working out - thanks for humoring me. :clapping:

No problem, I enjoy helping out. Had to muck through this stuff on my own a while back, now I make sure I keep up on what I need to.:biglaugh:

 

[Shuriken]

It's all relative, the air at higher elevations is not as "dense" due to lower air pressure, not oxygen content. What you will find is that the higher up in elevation you go, the smaller the main jets as the bike would tend to run richer all things being equal than the same bike at a lower elevation.

This is true. Every single bike I have owned has run worse at my elevation (5700-6660) until I have rejetted it with smaller fuel jets. I've taken several of my road and dirt bikes well over 8,000ft and they nearly lose all useful power at around 10,000ft. 3rd gear useful power becomes 1st gear useful power that high up.

I just went from a 128 main in my dirt bike to a 122 main and it runs a whole lot better.

I may have missed it, but did someone say how you put the end cap back on the muffler after it's drilled and does exhaust still escape around the perimeter of the end cap?

 

[Thevmaxrider]

I have seen guys make spacers out of washers, turn the end caps a few degrees, drill holes to match the holes in the end cap, put the spacers behind end cap, and re-rivet in place. Gives the exhaust a stock look, but retains the loudness of the drilled exhaust as the holes are still there and the gases go out behind the end caps.

 

[lankeeyankee]

No Problemo my burrito supplier! I mean to only share this secret site with you but as usual I goofed up and made it public.. They are awesome on prices and located in MO, so shipping should be pretty quick to TN.
The shipping is a lil on the high side but I ordered 4 main jets and 2 pilots for the scooter.
I wish they had different pitch needles for my frame flexxer. I am really trying to tune this thing for 6.80's 102MPH

:th_favorites24:

Thanks Lankee! Best online prices I've seen! Does anybody know the pilot fuel jet type for a Vmax? To me N151.067 looks correct by looking at the picture.

 

[Jaoteay]

I may have missed it, but did someone say how you put the end cap back on the muffler after it's drilled and does exhaust still escape around the perimeter of the end cap?

As much as I hate to admit this I went to Harbor Freight and bought a "Nut Riveter" It allowed me to put a rivet that had threads into the original holes. So in theory I could just remove my spacers (nuts that are too big for the bolt) and it should seal pretty well (probably not air tight but I'm guessing good enough).

Damn.. Now that I have this louder sound I Want to keep it... all I have to do is convince the old lady that I need a full exhaust...

 

[Jaoteay]

No Problemo my burrito supplier! I mean to only share this secret site with you but as usual I goofed up and made it public.. They are awesome on prices and located in MO, so shipping should be pretty quick to TN.
The shipping is a lil on the high side but I ordered 4 main jets and 2 pilots for the scooter.
I wish they had different pitch needles for my frame flexxer. I am really trying to tune this thing for 6.80's 102MPH

:th_favorites24:

What size jets should I get? I assume that I'll want to get a few different ones. I live up in Colorado so the elevation up here is 5200 ish... (Not sure if that makes a difference or not).


(Just to double check - The Morley jet kit won't make much of a difference on a bike with stock headers?)