I hae a 99 ZR600EFI. *When it is cold, it appears to work fine. *As it warms up, I loose top speed (50-60 mph max) and the sled seems to flood at wide open throttle. *Up to half throttle, the response seems to be fine. *The conditions are warmer than usual (1-2 deg C) in the days, and cooler at night (-1- -2 deg C). *The snow is frozen like cement in the night with no loose powder. *I have heard that the fuel injected sleds have an enrichment mode during engine overheating situations. *If this is tru is there a way to bypass this to confirm this is what is happening?? *I havev already tried unplugging the temperature sensor, no difference noted..

Thanks All http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/confused.gif

hmm... *Well, what to do...

I would first do a compression test on your engine to rule out an engine failure.

Next What is your peek RPM? *At wide open throttle, you should get between 7800 and 8400 RPM depending on the condition of your clutch.

The efi's have a fail safe mode. *If an sensor has detect a problem, failed or become disconnected (wiring problem) the computer will put the sled in to a fail safe mode. *Your plugs will be black and your preformance will degrade.

You can use an ohm meter to check the sensors. *I have book at home with the values.

Also check your computer's ground wire. (located on the steering post). *This is a common problem area.

newf

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (newf @ April 22, 2002, 11:57am)</td></tr><tr><td id="QUOTE">hmm... *Well, what to do...

I would first do a compression test on your engine to rule out an engine failure.

Next What is your peek RPM? *At wide open throttle, you should get between 7800 and 8400 RPM depending on the condition of your clutch.

The efi&#39;s have a fail safe mode. *If an sensor has detect a problem, failed or become disconnected (wiring problem) the computer will put the sled in to a fail safe mode. *Your plugs will be black and your preformance will degrade.

You can use an ohm meter to check the sensors. *I have book at home with the values.

Also check your computer&#39;s ground wire. (located on the steering post). *This is a common problem area.

newf[/b][/quote]
I have already checked the engine compression. *It is a strong 120 on both sides. *I have as well checked the engine grounds. *I also have a overhaul manual on the sled. *The only reading I found to be not correct (and could cause the problem) is the coil. *The resistance reading is approximately 100 ohms above normal. *To specify, that reading is 100 ohms bove the 20% tolerance. *Myself and my cat mechanic have found these values in the manual to not be correct always. *This reading from the coil was taken earlier this winter as well, and the sled performed normally. *Anyway, this is why I have decided to post a note. *Just to see if anyone else has had this problem..

Newf as well....

Did you have your Arctic Cat mechanic check the TPS?

I have seen where the TPS was out of alignment and the engine would act "funny" *Going to peak RPM then dropping. *Stalling or almost stalling. *Loosing power around 6000RPM, excess fuel on plugs...etc.

newf

Once forgot to tighten the main jets in my zrt 600 sled ran great up till full throttle then bog. *Pulled the bowls off and sure enought there were the mains sitting in the bottom.

just to let you know arteecat * * no jets on a EFI sled just injectors

1000-IMP good call on the e.f.i. carb deal. MIKEZR, have you checked the stator? there is a low speed and a high speed coil in there, they adjust air fuel mixture to the injectors. i had a similar problem as you do with my 600, i checked all the stator coils and the high speed coil was cooked. i got a new stator and it was like new again. something to check out. IMP-1000, mail me to talk about some T-CAT stuff.