550 fan carb. mod - Snowmobile Forum: Your #1 Snowmobile Forum

sourdough doug · 03-17-2007, 04:12 PM

It sounds like the old 100 mpg carb story, but here goes- supposedly there is a slide change in the mikuni that does almost double or more the mileage most of us are getting. As well, no change in jetting although I would do anything to get better than the 6mpg I get now. Has anybody got any info on this..

sourdough doug

**smallengineguy** · 03-17-2007, 06:18 PM

You should be getting WAY more than 6 mpg out of a 550 fan! Sounds like there may be an issue with it.

JimKrajnik · 03-19-2007, 01:35 AM

I have an 04 550 Rev MXZ. I have boisen reeds and UFOs, I get probably 14 miles to a gallon.

jeanluc · 03-19-2008, 11:55 AM

Can i ask you questions about my 2006 rev 550fan?
I did install boizen 2 stage reed valves in it and
since have problems to find a quality idle.
Please can you help me
Tanks J-Ls

locky · 03-19-2008, 05:19 PM

Quote:

Originally Posted by smallengineguy

You should be getting WAY more than 6 mpg out of a 550 fan! Sounds like there may be an issue with it.

He's from Canada and maybe meant Liltres instead of gallons. I sure hope so or he has bigger problems than he's aware of.

**smallengineguy** · 03-20-2008, 06:40 AM

Quote:

Originally Posted by jeanluc

Can i ask you questions about my 2006 rev 550fan?
I did install boizen 2 stage reed valves in it and
since have problems to find a quality idle.
Please can you help me
Tanks J-Ls

Check your plugs to see if they are wet and oily looking. Are you sure everything was installed correctly?

jeanluc · 03-20-2008, 09:57 AM

Yes ltook them out 3 times and make shure a have no air leak with hose on propane tank,and plugs are at 0.18(specs)so i made 3 plugs check (main jet)atfull trottle for 1/4 mile, color is lighter then brown coffe i would say more like chocolat milk shake. test no2(jet needle) +- half trottle and it,s the same color.Test no3,i let idle for 5 minute and color is dark brown no,t to oily.As i touch the trottle a bit from idle it is to rich and float level are on specs.thanks every body to try to help me. Discourage J-LS...

**smallengineguy** · 03-20-2008, 07:54 PM

Reeds put in the right way? Sounds like they are not closing all the way.

jeanluc · 03-28-2008, 02:26 PM

hey guys i fix my idle problem.It was that thepilot air screws on the carbs were to close,iphoned to the dealer to have the specs on the adjustement and it was 2 turns on the air screws.I had 1 1/2 biggg different, It work just like new.
Thanks Guys for all the advise it opens my eyes to find the problem were it was
J-LS

jeanluc · 04-03-2008, 02:50 PM

Hello jim i have boisen reeds on my 550 fan ,what would be the inprouvment to ad UFO like you did and what jet do i need to change?
Thank you J-LS