Suzuki ATV Master!
Join Date: May 2014
Location: Middle of Alaska
Carbs and flooding issues
There are basically two types of common carburetors used on ATVs. CV and standard. Both have slides.
CV = Constant Velocity. The throttle cable controls a butterfly valve on the engine side of the carb. The slide is operated by vacuum and uses a rubber diaphragm and spring combination to regulate how fast and how far it moves. The slide also has the Jet Needle.
Standard, often called Round Slide, but not all have round slides, the throttle cable directly controls the slide. The Jet Needle is also attached to the slide.
When 4 strokes flood, it can be very difficult to un-flood and even more difficult when using a CV carb.
The choke on all of these carbs is actually an enricher. It opens up another hole down into the float bowl that pulls more fuel into the engine.
Flooding is fairly common with ATVs, specially newly rebuilt or carb-cleaned ones.
If the ATV does not fire, pull the spark plug and look at it. If it is noticeably wet, you're flooded.
In CV type carbs, the float level is critical because of two factors. Set to high and the pilot circuit will get to much fuel and possibly the main jet will bubble more fuel up at idle. To low and the main jet will starve for fuel at higher speeds. There is a reason the tolerance is 1mm in all of these carbs.
Float level in non-CV carbs is also critical, but the tolerance is usually 1.5 to 2.5mm. Error on the side of to high and you typically won't have any issues.
Why is flooding so common in new rebuilds? When the engine doesn't start in the first couple pulls, the first thing people try is full choke, which floods it.
2013 Suzuki King Quad 500 AXi w/EPS
1990 Suzuki LT-4WD 250
and lots of snowmachines
Last edited by TUBBYTUBB; 05-28-2016 at 10:53 PM.