Installing UFO exhaust

[Mr. Max]

Installing UFO exhaust, carb setup?

So I've had this exhaust sitting on self quite a time now, I would like to install it but what I should do to carbs so it wont run too lean? I will buy sean's jet kit at some point, but just haven't got the money for it just now.. What if I just move needles up, or put in a little bigger main jets? Help please, It would be nice to hear them megaphones growling without engine failure etc.

 

[Sharky]

I'd say better wait until you can morleys muscle kit.....if you're going to pull carbies off etc best just do it once......and do it right.

 

[Traumahawk]

Re: Installing UFO exhaust, carb setup?

So I've had this exhaust sitting on self quite a time now, I would like to install it but what I should do to carbs so it wont run too lean? I will buy sean's jet kit at some point, but just haven't got the money for it just now.. What if I just move needles up, or put in a little bigger main jets? Help please, It would be nice to hear them megaphones growling without engine failure etc.

I'm assuming that your at stock jetting right now. With most exhaust (because they flow more air), will actually make you run a little bit rich. Most people when they go to an aftermarket exhaust will go DOWN to 150's or 147.5s. (going leaner)

I know with a kerker 4-1, and I think with marks 4-2, its recommended to shim the needles a bit after you install the exhaust.

Again, you DONT have to jet down, but you will be running a little bit rich, after the exhaust swap.

 

[Traumahawk]

Here is a thread that I started on enrichening the carbs vs back pressure.

http://www.vmaxforum.net/showthread.php?t=25903

 

[06VMAXIMUS]

Put em on!!! Adjust your mixture screws 2&1/2 out, shim the needles .040 and ride!

 

[Mr. Max]

Thanks for the info, I thought that it would run lean.. Well then I might just bolt that exhaust on, and add jet kit a little afterwards.

 

[Traumahawk]

Thanks for the info, I thought that it would run lean.. Well then I might just bolt that exhaust on, and add jet kit a little afterwards.

I thought the same thing when I first joined this forum, because I was used to cars.

I'm adding a kerker 4-1 when I get home. I'm currently running kerker slip ons with 147.5's, and will stay that way when I put the kerker 4-1, (well, I will shim the needles a bit).

Sean's muscle jet kit will probably go on this summer.

 

[Mr. Max]

About those needles, should I shim them down or up 1mm? I'm new to this type of carbs, but I suppose that down if it goes richer with more flowing headers.. I probably leave needles as they are, all my sparkplugs are quite light brownish coloured so I think that it runs almost too lean allready.. PO has tuned the bike in dyno, no idea what mains etc. has been used. I just don't like the idea of going any leaner by now.

 

[Rusty McNeil]

Here what I did on my if is and worked fantastic

Mains to 147.5's (I'm at sea level too so in my opinion 147.5 is a safe jet no matter the altitude)

Set the a/f screws to wherever the bike likes them best, prolly somewhere between 2-1/2, to 3-1/2 turns.
Enjoy

 

[jwood]

This is the info I received from Jon Cornell when i was installing a stage 7 kit and his Quadzilla Exhaust on my 99 prior to him passing... IT RUNS GREAT!

*****
Jeff,

Install the 165 main, needle in the 4th groove, pilot fuel screws 2.5 turns out. Drill the slides with the #19 drill provided. MUST install air correctors.

Use the stock slide springs instead of the Dynojet springs.

AFTER you synchronize the carbs, unplug the V-boost to be open all the time.

When installing main jets you do NOT have to unrack the carbs and take the float bowls off. Take the brass float bowl jet access 10mm screw out. Break the main jet loose with a flat blade screw driver. Now, get a wooden toothpick and push it into the jet and continue unscrewing it till* out. Reverse procedure with new 165 main.

*

Call me with any questions when installing.

*****

Sent by the Verizon 4G Data Network

 

[eggohead]

Great Info, I just put my 4-1 UFOs (Mike game me a hell of a deal)on last weekend. Still haven't started bike to to crappy weather. Where can you get the shims for the needles. I might be needing some help. I also plan on the muscle jet kit, just waiting for my seat from Sean now. Lots of little stuff to do. I plan on trying to Sync them hopefully this weekend and we shall see how it runs...Exhaust was easy to install compared to removing my old stock exhaust. I did solid engine mounts at the same time. And yes the carbs scare the hell out of me. Sean rebulit them for me 3 years ago.. It ran like a new bike.

 

[Traumahawk]

Here is a thread that goes into detail about shims....where to get, and where to place.

http://www.vmaxforum.net/showthread.php?t=28005&highlight=needle+shim