Tuning

[Nowheretogojs]

Was up at Get a Grip running today and started to lean out my MT. Got it running good on top. But 2 issues. First its getting a little warm (air temp was right around 98 99*f and prolly 95+ humidity) engine was in 250 270 range. Also I'm not getting the bottom end punch I was expecting. Any ideas? Leaning the bottom was causing the idle to come up a bit high. Also what carb comes on these out of the box?

 

[Guest]

If the idle comes up due to leaning you can lower the idle stop screw a bit.

The carbs are not a name brand.

 

[Nowheretogojs]

Throttle stop doesent touch even before. If i cant get it to tune with this carb I may swap it out. I see there are allot of options out there for it and don't want to over fuel it or under fuel it. Is there really that much of a difference from carb to carb? Like i hear about this 880 and seen the 686 or whatever and don't quite understand what the difference is.

 

[Guest]

Either the 668 or the 990 will work. I run the 990 with no issues.

 

[rampage idiot]

The stock carb is a RUI*ING mine was junk could never get it tuned right I put on a wt668 and have no problems I am trying a wt 990 next

 

[Nowheretogojs]

What makes one carb more suitible than the next. Venturi size or jets? Someone here has to have this info or everyone here would be going into a carb change blind.

 

[Guest]

Not my expertise, but there is lots of info on here. Just do a search on the topic it will keep ya reading all day

I have always used what is recomended. I'm sure someone will chime in.

 

[rampage idiot]

Like RCDAD said there are guys on here that have a bunch of exreriance with the carb thing like he said search and see whats out there because there is alot, I just read and ask I have only been steered in the right direction on this forum alot of good guys willing to share the info they have. The wt668 I am running is a great carb but it has a known low end bog associated with it not bad but its there, from what I see most are running a wt990 no real issues but the one thing about it is it does not have a choke, same carb as the wt813 without an accelerator pump and what I read the 813 has throttle shaft issues,ok thats what I have learned

 

[Deluge]

The stock carb is probably a 603/668 clone. Which do tend to lag on the bottom end. The 990 eliminates this lag.

I'm working on getting some official specs. I'll post them when I get them.