[snowmonh]

Hi Guys, Any help would be MUCH appreciated!!!

PROBLEM: Quad will idle but when you try to give it throttle the machine boggs, backfires through the carb, and dies. Can't even get it going enough to get it to move.
- Started having this problem while my son was moving rock (heavy loads) after about 2.5 hours of work.

HISTORY: I bought this quad new and have always taken really good care of it. I go through the carb every spring but have never checked the valve gap. I did have to replace the bottom radiator hose after finding a leak in March. No leaks since

Trouble shooting steps to this point.
- Checked carb. Cleaned all parts. Verified float position.
- Checked fuel mixture screw position (2.5 turns out)
- Tried several fuel mixture screw adjustment none of which helped the bogging.
-- 1 turn out
-- 1.5 turns out
-- 2 turns out
-- 2.5 and 3 turns out.
- Checked spark and plug condition.
- Checked basic wiring for opens, shorts ect.
- Checked CDI unit. Nothing notable found

Im concerned my son might have over heated the motor and maybe screwed the valves but not sure. I inspected the valves but didn't find any problems.

Does anyone have any ideas? Thinking I might have to take her into the steallership.


Thanks,
Tim from NH

 

[Jeffo]

Hello, I have the same problem it sounds like.
Backfires thru the carb, idiles fine and dies when you increase throttle.
I am working on a 650 Artic Cat which was sunk in water.
I just noticed that the is no air being sucked down thru the front carb, you can block that carbs intake and the engine will not try to stall.
I will let you if I find out anything out which could fix this problem.

 

[Lélo]

My 650 h1 did the same, but now it's fixt..

Hello, I have the same problem it sounds like.
Backfires thru the carb, idiles fine and dies when you increase throttle.
I am working on a 650 Artic Cat which was sunk in water.
I just noticed that the is no air being sucked down thru the front carb, you can block that carbs intake and the engine will not try to stall.
I will let you if I find out anything out which could fix this problem.

The ruber bout beetween the carb & piston was crack,very hard to see the crack......no more back fire & lose of power..