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Discussion Starter #1
I have a 1990 Wildcat Mountain Cat 650. It runs great, but when its been sitting overnight, it takes 12 pulls to fire. Once its been running for a minutes or so, it will easily start with one pull. Once the engine is really good and warm, even if it sits for 20 minutes, it will start with one pull.

It almost seems to me like the carbs are dry after sitting for the night. Someone told me they figured the carbs were leaking (not likely, I can't smell a hint of gas), or the fuel is siphoning out back down the fuel line.

Any ideas?

I'm pretty sure the choke/enrichment setup is set correctly, but how do i know for sure?

Ryan.
 

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Discussion Starter #2
Ok, I just made a liar of myself. I just went outside and it started on the fifth pull!

I had made some adjustments to the idle speed screws yesterday, it must have worked!

This leads me to ask another question about my idle speed. If you throttle the motor up and then let go down again, it will idle at something like 2800rpm. It always does this. Then, if you turn the key off, wait until the rpm gets to 1800 , if I switch the key back on, it will idle no problem at 1800.

So, it seems like the throttle is stuck, but the cables don't seem loose. Could it be possible that the slides are sticking? Or just one of them?

Ryan.
 

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i don't think the slides are sticking.

any work ever done to the engine? seals, rings, carbs cleaned?
how many miles are on the engine?


nice sled by the way, i'm leaning towards buying one around the same year in the spring to fix up over the summer.
 

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Running stock jetting?

If so, set pilot screw at or around 1-1.125 turns out from light seating, warm up engine to normal operating temp, THEN making sure sync is correct first, adjust idle speed screws equally until 1500-1700 rpms are attained, again follow by rechecking carb sync

If it still wants to idle higher than normal and is requiring more than 4 pulls cold (supporting lean symptoms), look into having carbs professionally overhauled, if float levels were in lower than neccessary position (allowing higher fuel levels in bowls) it would blubber like theres no tomorrow at idle and just off idle

Flat land operation (below 2,000' above sea level) these particular machines are safely run on 370 mains making very good power on top and torque in low to mid range with stock pilots and needle jet settins from the factory using pump fuel
 

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Discussion Starter #5
I don't remember what the jet sizes were when I rebuilt the carbs last year. I am an auto mechanic so I would consider the rebuild I did professional. ;-) The floats were set correctly, I was very picky about cleaning the carbs and adjusting them.

There are 2200 miles on the odometer, but I suspect it has up to a thousand more on it as the speedo cable was broke when I got it, and they used it for a couple years with the broken cable. I don't believe any work has ever needed to be done as it runs like a dream otherwise, and everything appears stock.

As for syncing the carbs, I would make a minute adjustment on one, and then the other, with both starting at 1.25 turns eventually ending up at idle RPM. I honestly think something is holding the slides up, but not sure yet. I think I will take them apart again, and look for scoring as I remember some rubbing marks on the side of one of them.

I really like this sled, I just got it last winter. Has tons of power, its amazing, you can cruise at 70mph, and still have probably half throttle to go. Never had it going more than 75 or so, nothing flat or safe enough around here to try it. Sure is no comparison to my old Nordic 440.

Just went outside and started it again. It starts quite nicely on the fifth pull, which I am happy with. At least its consistent and beats 12 pulls. When it idles too high, its at 2600rpm and is at 1700 when I "force it" to idle properly. Not bad, but could be a little better.

Assuming I do have the carbs synchronized properly (don't have a sync tool, did it by ear), if I open the slides a little more with the adjustment screws (slightly higher idle), should that help with the number of pulls on the rope?
 

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No, not really,, the further "in" you turn low speed (pilot) screws, the better it'll start and return to proper lower idle as well as this richens up the idle circuit,, also tell me that you didn't use "spray canned" carb "linkage cleaner" to do the overhaul,, that stuff is only for grime on outsides of carbs, not removing varnished fuel deposits and does literally nothing to help with clearing of fuel passages internally
 

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Discussion Starter #7
Ok, good to know, these carbs are an enigma to me as I'm used to automotives, tractors, various small engines etc.. I was thinking I had to keep the screws out more. I will give them a bit of a turn inward and see if that improves things.

I haven't owned one of those spray can carb cleaners for over 15 years. I have a 4L can of carb cleaner that you soak the carbs in. This is what I did, came out looking like new.

Thanks for the tips, I'll be sure to keep you informed.

I just wish we had some snow already!

Ryan.
 

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<div class='quotetop'>QUOTE (rlester @ Nov 12 2009, 11:13 PM) <{POST_SNAPBACK}></div>
Ok, good to know, these carbs are an enigma to me as I'm used to automotives, tractors, various small engines etc.. I was thinking I had to keep the screws out more. I will give them a bit of a turn inward and see if that improves things.

I haven't owned one of those spray can carb cleaners for over 15 years. I have a 4L can of carb cleaner that you soak the carbs in. This is what I did, came out looking like new.

Thanks for the tips, I'll be sure to keep you informed.

I just wish we had some snow already!

Ryan.[/b]
The only way!
 

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a quick and easy way to sync those carbs, without a tool is, take the airbox off, and stick ur fingers in both carbs. pull on the cable and feel to see if the slides move at the same time. Adjust the cable as nessasary to get them as close as possible. And go thru the whole range of the slides, not just at an idle.

Not sure exactly what the idle speed should be, by my 92 ext is idleing at around 2500 rpm or so, if I remember right.

My manual staes for a wild cat idle rpm to be 2000 to 2500 rpm.
 
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