Full Choke Only Suzuki QuadMaster 500 2001

[jimybud]

Below is a quote from a response to similar question from yesterday: 

"Easiest thing to check is trash in the main jet.  if it idles fine, then the idle circuit and low speed jet is clear.  if it bogs off idle that's when it's transitioning to the main jet." 

I will go ahead and open up the carb and check the main jet, but please respond to this post as if the main jet is squeaky clean.

Below is my post:

Only starts and runs on Full chock. 

Does not matter what position I have my "mixture" screw.   Tried it at zero, 1 turn, 2 turn, up to five turns.  Spent a few hours confirming that the position of the mixture screw does not resolve issue.

Runs great at idle and if I slowly engage throttle, it will rev up as expected.  But, quick rev up or when I am trying to drive it, it spits and sputters and looses power.

I also use a propane bottle and did not find any obvious leaks, and the vacuum port is hooked to fuel peacock and I also made sure to simply block the port with my finger to see if that would resolve the issue.

New Carb (after market), New Coil, Fresh Gas.  No leaks at manifold boot, hot battery.  Good gas flow.    Runs too good to be a valve issue, or cylinder, great compression.

I can move the choke out a tiny bit, and it will still run, but will still bog down when I try to power it up.

I also have a 250 trail boss Polaris that I require to run at full choke, but it has power at all throttle potions.

I suspect it is running rich as the choke is on, but will not run with it off.

Any details would be appreciated.

[MarkinAR]

Ha, that response sounds like something I would say.

so yes, most likely just flooding itself to death.  I'm assuming by aftermarket carb you mean a chinese clone?  The jets on those are NOTORIOUS for not being stamped, stamped wrong, way wrong size, just junk in general.  I've used a few out of necessity and they either fire right up or you spend time tinkering to get them to 80%.  Do you have the OEM?  If you do use the original jets in the clone carb, that works sometimes.  I've also had the clone carbs come in with the float terribly high or low, give that a check also.

Your situation reminds me of a clone carb on a ATC 185s I had a while back.  Couldn't get that thing to run for anything if you stabbed the throttle.  This issue was the carb passages were wrong not just the jets.  I ended up putting a small main jet and raising the needle a clip or two and got it to about 90%.  Good enough to pop wheelies non stop because that's what 3 wheelers are for!

[meinsheizer]

I would still recommend a compression check to eliminate the valve lash issue. And depending on mileage your timing could be off enough that the valves are opening early. The chains can stretch over time and cause run issues.