Do any of you guys with 300's know anything about them not idling right? I can not get it to idle steady,
I have done alot to it, arctic cat even let me swap the carb for a new one off a 04, no charge and even out of
warranty[img]i/expressions/face-icon-small-smile.gif[/img] anyway, I have put k&n filter, dyno jet kit ( had that on and off twice, not much improvement either way)
I have gone lean, rich fuel filter, cleaned carb on and off, only has 250 miles on it and I treat it great. I love my
ride and it runs great, but the idle thing is driving me crazy! [img]i/expressions/face-icon-small-confused.gif[/img]

 

Try checking your valve clearance, even though it is low miles we have found some of them out of adjustment and won't idle correctly.

 

Spark plug not gapped correctly, either too wide or too close.
Air leak in the intake tract, maybe missing a gasket or split rubber.
And like tork said, check valve clearance.

 

hey hondabuster, thanks, also got all the intake off the new 04 from the airbox to the manifold,
so, lets assume that the guys at the shop didn't check the valve clearance, like I said, I tried to check
it, I have the feeler guages bent for the intake and exaust, I have the shop manual, but, the only
thing it don't tell me is, How do I get to top dead center, and know for sure it's top dead center?
if anyone will reply to this this morning, I will try it today.
Also, the plug gap calls for .024-.028, I have tried them from .024 to .026, and I tried a $10.00
Nippendenso iridium plug.

 

I dont have an ac but ill guess, there has to be some sort of way o view the timing mark. Look for a female hex head, bolt in the side of the case ,that would give you a view at the flywheel, it would be the side opposite of the clutch side. If you take the spark plug out, itll turn easier. Using the pull starter, slowly pull while watching the flywheel...you should see a "t" or other mark. When you line it up, thru the hole, check the rockers, they both should be loose. If they arent loose then, you need to spin the motor over ,360 degrees from there to the mark again. The camshaft is half speed from the crank.
I would think the shop manual should show this. Let me know how it goes.

 

When in doubt roll engine over until intake valves are fully open and adjust exhaust valves. Then do the same for other valves.

 

So, When the rocker arm is down on the intake side, I find the tdc mark at that point, and adjust the exaust valve
side, then when the rocker arm is down on the exaust side, find the tdc mark at that point and adjust the intake valve?
I was thinking that on a cingle cylinder engine, you adjusted both valves at the same point.

thanks for the help, I am mechanically inclined, but I am new to going so deep on a quad motor.

 

what tok was telling you, will work. Hes saying that, because hes assuming youre not seeing a timing mark. If you can see a timing mark, and youre on it, then both can be adjusted at the same time. Basicly, if you can wiggle the rocker, it means there isnt any valve spring tension on it, and its at a spot you can set the lash. Did you find the timing mark?

 

Yes, I found the mark, I'm just a little unsure as to how to proceed, The Arctic cat manual does say, find the mark on
the compression stroke, then adjust valves.-Meaning both. so is that right? The intake and exaust stroke seem to be very
close to each other when I hold my finger in the plug hole, it's so close that I am unsure if I am at the right spot or not,
so your saying that if I can't move the rockers at all, that is the exaust stroke? I'm a little confused.
The rockers seem to move a little in both positions.[img]i/expressions/face-icon-small-confused.gif[/img]

 

Hey, both of you guys are off right now, but I think I've got it, from what I can tell, based on the instructions
in the manual, and what you have told me, when I rotate the engine with the pull start, I watch for the mark the entire time
I rotate it, the mark only comes up once, and it looks like, everytime it comes up, the rockers, valves, and piston are always in
the same position, I used a Craftsman lazer level to line up the marks exactly, and the intake side seems to be pretty close
to spec, but the exaust side seems to be way out, it wiggles alot, so maybe thats where my idle problem is coming from,
I'm heading out to make the adjustment, and if it works, I may go ahead and re-install my jet kit per instructions, and see
if it makes a difference this time. you guys let me know what you think, And I am going to adjust the valves mid-way in spec
scale, so maybe that will be right, I don't want them too tight or too loose.
Thanks again.