05 King Quad bogs after warming up
 

Howdy! New to the site but could use the help of the experts.

My son has an 05 Suzuki King Quad 700 and it has two issues:

1) Bike runs perfect when it first starts. Give it full throttle and it takes off no issue. After it warms up, won't get out of its own way! Bogs and misses like crazy. Could this be a tps?

2) There's a noise coming from the rear. I thought it was a cv axle but after grabbing the axles and giving them hard pulls several times back and forth no noise. If I sit on the quad it sounds like metal to metal clunk. I think it might be bushings be to be replaced but was wondering if there's any suggestions on how to determine what might be causing?

Appreciate any help and guidance that you can offer.

You won't get noise from a CV unless running and under load, if there is a lot of play (backlash) in a joint it indicates wear, but it is really bad to tell which joint has gone unless you have a split boot, in which case, it will be that one.

With the EFI the problem could be anything, welcome to the wonderful world of EFI. If the EFI warning light isn't on, most likely thing on a King Quad, is the tiny filter in the back of the injector bunged. Blow the injector out with an air line. If that doesn't work, a new tea bag filter in the fuel tank. Experts only, as Suzuki didn't sell them at first and you have to strip the plastic filter assembly to fit one, unless it already has a later, replaceable filter, fitted. Or the fuel pump could be supplying low pressure. As it only does it hot, may be the temp sensor telling lies, could be worth trying a new temp sensor (behind the cylinder head). If the warning light is on, you could, in theory, jump two wires on the diagnostic plug and get a fault code up on the speedo, this code tells you what is wrong. Which wires to jump, and what the codes mean, will be somewhere on the internet, but it may be best just to let the dealer stick it on a proper diagnostic computer.

Can I ask because I'm not familiar what all do those have for monitoring? Temp sensor is a given but does it also have a map and or an 02 sensor. When your first starting up the quad it may be running in open loop meaning it will run off a fuel map that is purely based off temp (usually) and when it warms up it will start using all the sensors to fine tune the mixture. I'm not sure how smart the computer is in that machine but sometimes un plugging something like a map sensor can kick it back to open loop which will make it run better. In my experience with efi temp sensors that have gone bad usually make starting and cold running operation much harder and once the machine is warm there is enough other input it will run better. Ultimately yes you will need to get faults from it or if you have a service manual you can attach a meter on everything checking resistance and continuity.

Thanks for the advice on both items. I'm going to look at both issues as you've suggested.