ATVmechanic

You may not be getting enough fuel. It may be time to remove that carb and give it a good cleaning. How is your choke working, is it fully operational? If you adjust you idle control screw, does it run better?

Exactly...you can run a low restriction high performance muffler..running with no muffler for a prolonged amount of time is not good.

Any luck with this?

Diesels.....nice machine, but I prefer the gas model.

If you are looking for "sympathy", it's in the dictionary between "sh**" and "syphilis".

I got rid of the 500, 2009 model, never did get to the cause of overheating. Have just picked up a new 550sportsman 2 seater, larger radiator now. I am trying to get the electronic control module set for hot climate, service doesn't know much about it yet. This is probably why all the quads we hear about boiling up here are Polaris.

Congrats on the new quad. Yeah, I believe you will need to get it set by the delaer most likely to have the fan turn on sooner and stay on longer.

Found out on the Ruby you have to let it run no less than 7 minutes or the motor starts to warm up. It fouls out a $15 dollar plug. I know the Rubicon and Rincon use this plug. Do not know how many other models this affects. Also watch how long the choke is on. These plugs are real easy to foul out.

Do you have the spark plug # handy?

yes, I wouldcheck that reverse switch.

is there a difference in the performance on a NGK vs. CHAMPION spark plug? it is on my 03 400 ex.

I would not put champs in a Honda...use:

Spark plug Standard: DPR8Z (NGK), X24GPR-U (DENSO)

For extended high speed riding: DPR9Z (NGK), X27GPR-U (DENSO)

Here are the specs:

Carburetor BSR36

I.D. Mark 5YT1 00

Main jet #142.5

Main Air Jet #35

Needle-clip Position 5JFC39-2

Needle Jet P-0M

Pilot Air Jet #65

#165

Pilot Outlet 1

Pilot Jet #22.5

Pilot Screw (Turns Out) 2.25

Bypass 1 0.8

Bypass 2 0.8

Bypass 3 0.8

Throttle Valve Size #105

Starter Jet #70

Fuel Level 4 - 5 mm (0.16 - 0.20 in)

Float Height 13 mm (0.51 in)

Engine Idling Speed 1,450 - 1,550 rpm

Vacuum Pressure at Idling Speed 33.3 kPa (9.83 inHg)

Good to see that you found your issue.

drill a hole almost as big as the studs with a left handed drill bit and that usually grabs it before it actually drills a hole and if that doesn't take em out then you have a hole to stick a screw extractor into to take them out if that still doesn't work just drill it out with the closest tolerance you can a run a tap through it to clean up the metal shavings and threads and get new studs make sure you get the hole in the center otherwise you got other problems

Exactly...use an "easy out" extractor.

The horizontal marks should be level with the cylinder head cover mating surface at the same time the "T" mark aligns with the index notch on the case cover. The vertical line on the cam sprocket should point straight up.

Are the back tires locked up?

If the kill switch is good, and you have no power at the coil, then there is a problem with the connection between the kill switch and the coil. Get out the electrical tester and start at the battery and start checking for continuity between every junction, switch, component and what not. Check your ground wires. Double check that kill switch, with the key on, there should be power at one pole of the kill switch, when you turn the kill switch to on, there should be power at the other pole.

I agree, start testing electrical. Attached is a wiring diagram for you.

Just asking, did you try a new spark plug?

Yes, it sounds like ignition to me. Maybe as simple as a new plug, wire, or coil.

Is it overheating? Is that why you feel the fan is not coming on when it should?

It may very well be your fuel pump, shutting off after getting hot. Whe you run into an issue where it will not run, start testing circuits to see what system is off...fuel or ignition. If it is overheating, I belive it does have a cooolant temp sensor on that machine that could be your issue.

Thanks Folks! Things aren't always what they seem though. The intake boot between the carb and jug was cut a little from a (I guess) too narrow clamp. Must have been that way from the time I installed it and sucking air. Anyway, ordered a new one. Just out of curiosity and cause I saw a bottle setting close by, I smeared a nice coat of gorilla glue around it. Thing hasn't ran better since I bought it.........

Thanks, Dave

You are absoultely right about things not always seeming wha they are. Glad you fixed your issue.

Congratulations on the new quad. I would really need to hear the noise but I believe that a slight rattle at idle is normal. My suggestion would be to bring it to the dealer for a check up and have them document it, saying that it is fine. This way you have some peace of mind.

Try these tests:

Check the main switch which is located near the headlight I believe. It should be a 2-pin connector, white. Touch the one probe to the brown wire terminal and the other to the red wire terminal. There should be continuity when the switch is in the on position and no continuity when the when the switch is in the off position.

Check the start switch. Trace the wires from the left handlebar to down to the connectors. Disconnect the 6-pin connector. Set the multimeter to ohms of resistance. Touch the one probe to the black wire terminal and the other to the blue/black wire terminal. There should be continuity when the switch is pushed down and no continuity when the when the switch let off.

Check the kill switch, you'll need to remove the front fender. Trace the wires from the left handlebar to down to the connectors. Disconnect the black two-pin connector with brown and red/black wires. Set the multimeter to ohms of resistance. Touch the one probe to the red/white wire terminal and the other to the red/black wire terminal. There should be continuity when the switch is in the off position and no continuity when the when the switch is in the run position.

Check the clutch switch. Trace the wires that come out of the clutch switch and disconnect their two-pin connector. the clutch switch connectors from the clutch switch.

Touch one meter probe to the black/yellow wire and the other to the black wire. There should be continuity when the is pulled in and no continuity when the when the lever is released.

Try taking it to another Polaris dealer, that should be fixed under warranty. I would leave it there until it was fixed and have them call Polaris and tell them the situation.

Welcome!

There are some videos on Youtube. I'm interested in your results, keep us posted!

[ame=http://www.youtube.com/watch?v=_3GwyKBIRtE&feature=related]YouTube - Turbo YFZ450 Dyno Results[/ame]

[ame=http://www.youtube.com/watch?v=tKSqtp-7DuU&feature=related]YouTube - MotoDani Yamaha YFZ 450 Turbo[/ame]

[ame=http://www.youtube.com/watch?v=tdtFcCnS-Z8&feature=related]YouTube - yfz 450 turbo brazil[/ame]

Google search on the web, they are around.

Here is an example:

POWROLL PRODUCTS FOR THE YAMAHA RAPTOR 350

Jet kit: Poly Performance Inc.*::*Engine Performance*::*Yamaha*::*Dynojet Jet Kit: Yamaha Raptor 350, Fox Racing Shox, Elka Suspension, Arctic Cat, Bombardier, CAN-AM, Honda, Kawasaki, Polaris, Suzuki, Yamaha, KTM, Beard, Twisted Stitch, FMF, OMF Performance,

Here is a thread about the suspension on a raptor 350: http://www.quadcrazy.com/atvforum/yamaha-atv-forum/3905-raptor-350-shocks.html

Here are some possible things that could cause this type of condition:

Pilot screw maladjusted

Pilot jet, or air passage clogged

Air bleed pipe bleed holes clogged

Pilot passage clogged

Air cleaner clogged, poorly sealed, or missing

Fuel level in carburetor float bowl too high or too low

Fuel tank air vent obstructed

Carburetor holder loose

Air cleaner duct loose

But it sounds to me like it's fuel starved. Try what Dirtdemon said and also check your carb float. Yamaha carn floats get mesed up because of corrosion around the pivot pin, causing the float to get stuck in an incorrect or low position.