Howdy all, new'b here. (to this forum) I have had my Vinson for about 8-9 months. I picked it up locally with only 219 miles on it, so the dang thing is like new, but it has one MAJOR issue with I think ya'll are going to tell me is a design flaw, vs. an actual problem.

I do want to state before I tell you that the problem is still there after I have adjusted the valves (what a job that was) and removed the carb and had it cleaned by a motorcycle pro.

ISSUE: When I am heading down a REALLY steep hill, almost vertical (or not necessarily completely vertical) the machine stalls out, every time! I thought could have been a dirty carb, clogged jet etc., so I removed the carb and had a friend who has about 50+ carb rebuilds under his belt give it the once over and run it through the ultrasonic cleaner. He said the idle jet was a bit dirty but after cleaning, generally it is now back to factory 'clean' condition now. BUT the problem persists.

Anyone know of or is aware of, or heard of this problem and have a little insight for me? I am at my wits-end and believe it is just a design flaw with the carb.

HELP!!
(Thanks in advance)

 

Maybe just me,but never was a fan of just cleaning a carb. If you're going to tear it down install a new carb kit. Problem could be loading up with fuel from a leaking float needle or float level out of adjustment. At least a carb kit can eliminate the carb as the problem. Plus check that it's getting a good fuel supply to the carb.http://www.ebay.com/itm/SUZUKI-2003-2006-LTF500-Vinson-Carburetor-Repair-Kit-Carb-Kit-/271555016716?hash=item3f39f0b80c&vxp=mtr

 

How full is your tank? The petcock is at the back, when not on reserve the fuel comes from a couple of inches above the bottom, so with the fuel at the front due to the angle of slope, the tank has to be fairly full.

 

I went ahead and ordered a rebuild kit and we'll see if that works.

 

The problem is the level of gas in the bowl. Your floats don't float like they did 10 years ago and they're not shutting the flow off before the bowl is too full. When you turn at an extreme angle, the gas flows into the intake and kills the engine. You either need new floats or adjust the float level to compensate for the lack of buoyancy.

 

Ok, so i installed the rebuild kit yesterday and the float height was corrected. There is another issue hopefully someone can give me some feedback on without me having to create a new post.

The dang quad runs fine, but only with the choke in the on position. Any thoughts here?

NOTE, it has been this way since i got it this past summer.

 

Still sounds like either something blocked in the carb ,wrong size or stopped up jets,plus make sure you have fresh fuel.Even a leaking intake manifold can cause this.Choke having to be held open is tell tale sign it's running lean somewhere.

 

OK, so here is todays update. I removed the carb again, broke it down and put it through the ultrasonic cleaner. Removed, rinsed in fresh water and cycled through the cleaner a few more times, rinsed thoroughly and dried with compressed air. Reassembled, reinstalled and still have the "choke must be in the on position" problem.


While The carb was cleaning I checked/thoroughly cleaned all the 'air' plastics and found no holes, cracks or any potential air leaks. (from the highest intake air breather hole to the plastic manifold between the carb and the cylinder) With the engine running, I can place my hand over the air intake hole at the end of the breather tube and the engine about dies, so I assume all is well there.


Signed:
Completely baffled

 

Might be a stupid question,but you do have the air box/filter installed? Have had some in the past forgot to mention that in their posts. Plus I'd recheck that you have the correct pilot and main jets. Plus spray a little carb cleaner around the intake manifold,base gaskets,etc and see if the engine rpms change. Plus looking at this carb,it has an air cap. A lot of people overlook these. If sticking or diaphragm is worn,leaking air,can cause problems. Plus has an updated part # for it. Item #32.Dirt Cheap Kawasaki & Suzuki OEM Parts & Accessories – Cycle Parts Outlet

 

Yes, air box, filter, and box cover installed and clamped. Diaphragm is clean, flexible and does not look to be worn.