1991 King Quad 300 bogs and dies

[tundrawolf]

Hi,

I have a 1991 Suzuki King Quad 300.

I bought it not long ago, and it has never run right. I bought a new diaphragm for it. It's sealed in that department.

It barely ran good before, and actually I got it to run fairly good, with a good pull with a clamp in air cleaner.

I put a snorkel on it, making sure to use pipe that would allow an ID as big as the carb intake flange, so there's no restrictions, and the same clamp on air cleaner.

I went through the carb again, even put a top quality Japanese rebuild kit in it.

It starts and idles perfectly. Has good power from idle to about 1/3, then anything past 1/3 throttle, or thereabouts, it just bogs down and completely dies. If I pull the choke in, I can get it to half throttle without it bogging down or dying.

It pops and backfires and sputters the whole time, then past a certain point the engine acts like I hit the kill switch.

It IS getting gas in the carb by the way, I put on a electronic fuel pump which helped things immensely. I put on a fuel pressure regulator and got the fuel to around 2 PSI.

I am at about 5,500 feet elevation, and the main jet is a 120.

I am considering coring out the main jet to a larger size to see if that helps anything. This quad is already such a gas hog, but maybe if it is jetted right it won't be so had?

Edit: It does actually run a tad better when it is warmed up.

Edited February 19, 2015 by tundrawolf