Originally posted by: elslayo
Hey guys, new to the board..

I recently bought a 95 King Quad (3000 miles on it) for hunting and it ran great for awhile. Lately though, it backfires when deccelerating, and has been difficult to start .

***Most likely running too lean as a result of the carb cruddying up. Clean all up and set float height.

I changed the spark plug and cap, drained the tank and carb for any possible moisture from condensation, and put gas line antifreeze in it. Same thing happened, and my bro in law says the valves may need adjusting.

***It's actually adjusting the tappets, but who worries about semantics? The valve lash needs to be within a certain tolerance. Too tight and the valves leak, causing lost compression and the likelyhood of a burnt valve eventually, and too loose means again lost power, increased noise and increased wear on the tappet and valve stem.
They're adjusted right when you get the bike but wearing in on the tappet surfaces and cam and stem makes em looser and wear on the valve and seat makes em tighter, and the two don't always cancel themselves perfectly, so you'se gots to adjust. Remember when the motor warms up the lash tightens up a bit. It's made to accommodate this.
You adjust the lash when the tappet is 'off the cam'. See, the valve is only opening, open, or closing a small portion of the time. Most of the time it's closed and the tappet rides on the part of the cam thats ground to be round, as opposed to the lobe part. Any time it's on the round and not near a ramp you can set it. Top dead center of the COMPRESSION stroke (not the exhaust/intake stroke, pay attention!) is stated in manuals so fools have a wide margin of safety when setting the lash. Here's how you do it perfectly, every time. No rocket science here.
Take out the spark plug, pull the motor over slowly with the starting cord with your little fingy over the plug hole and when you feel compression whoosh against your fingy then leggo the starting rope and you can set the tappets. You can be **** and make sure the thing is EXActly on tdc but come on... You don't need to. Off the cam is off the cam.
Anyway the tappet covers come off and you see the tappet screws and their jam nuts that keep them where they're set at. (I call it a screw but yours probably has a square head) You should be able to wiggle them a bit at this time unless they are tight as... never mind. Loosen the jam nut and back out the screw a bit. Intake side is next to the carb, get your .002 -.003 feeler gauge (looks like a spatula for flipping the worlds smallest flapjack) and slip it between the tappet end and the valve stem head. Tighten the screw on it till it slides freely but any tighter it would drag hard. Then take out the feeler, hold the screw and tighten the jam nut so the setting is preserved. Do the same on the exhaust side using the .004-.006 feeler gauge.
Put the cover caps back on. Ride.

Would you guys perhaps be able to tell me a little bit more, such as how frequently you need to do this valve adjustment and what the specs are, ie. -10 thou out or whatever. Also, How many turns from screwed right in is the idle adjust screw supposed to be set at ?

***Wherever it idles at the right speed. That's the big **** you can turn with your fingers you are talking about, right?

Do you think I should install the optional cooling fan on it? Any info would be helpful as I live in Northern Ontario and the nearest Suzuki dealer is a good distance away.

*** Mine is bored out to 330+ and I have never needed the fan. Save your money unless you are pulling trains with it.

Thanks in advance, and happy riding;-)

Originally posted by: elslayo
Thanx Glenlivet, I will clean out my carb, and try to find my old feeler gauge today and see if I can adjust the tappets. Your help is very much appreciated. BTW, when I bought my KQ I also got in the package deal an old '85 hardtail Lt230 for the kids, and it started running $hitty soon afterwards also (almost the same symptoms). I am not a mechanic by any stretch of the imagination, but knowing that water in fuel is responsible for a majority of backfires, I drained the tank, bled the carb bowl, and did get about a third of a cup of water out of it. However, that did not eliminate all the problems, so I cleaned the carb and adjusted the float height by trial and error, and changed the plug and cap, and now it's running a lot better. Unfortunately the tappets are making a horrible noise once the bike totally warms up, I wonder -are the tappet adjustment specs similar for that Suzuki engine? Are you a small engine mechanic by trade, or a self-taught owner? Also, did you bore your King Quad out because of wear or did you just want to have increased power? How much difference is there in power since the bore-out? Must be nice to ride in beautiful B.C scenery-did you have to change any carb settings to compensate for altitude where you ride?

Many, many thanx again