Take it to the Limit

General topics related to John Deere Snowmobiles
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jdfanmi
Posts: 30
Joined: Wed Nov 07, 2007 1:00 am

Take it to the Limit

Post by jdfanmi »

Rich,

I tried sending to your inbox but got an error

Oh the joy of having a Liquifire! Well I replaced the coil and thought everything was going to be okay. Drove it around for about 5-7 miles (at moderate speed w/ a few wide open bursts) and everything seems to be running okay but turned south when I got ready to put it away. I was going about 10 or 20 mph when I gunned it to get up a pretty significant hill in our yard and it began to bog and died after it came to a stop. The approach to the hill has a little dip/ditch so I do not know if it had anything to do w/ it. I tried to make as many observations as possible.

1. When 1st starting engine I let it warm up and engine seemed to want to race so I turned idle screws out until idle stabilized at 3200 rpm. After getting on throttle to take off and moving a bit engine would not idle at 3200 rpm

2. Sled ran significantly longer but ambient temp is quite a bit colder than when previously experiencing same problem. Temp gauge was not registering any temp during entire time I was driving

3. Took plugs out (put in new ones when replacing coil). Plugs did not look wet and had white to blueish spark when pulling starter rope. Blue flame did come out of the mag cylinder (once) when pulling over (pto side plug was still in).

4. Tried spraying starter fluid in air box to see if that would get it going (thought if it was not getting fuel that may help start) but no luck.

5. Engine pulls over with same effort when 1st starting it and after it dies


Any thoughts?

Justin
hamzam

Take it to the Limit

Post by hamzam »

I have an 80 Liquifire and it runs great ..which doesn't help your situation but I got rid of my low end bog by installing a blue Polaris primary spring. Now there's no bog which is great....FYI.
jdfanmi
Posts: 30
Joined: Wed Nov 07, 2007 1:00 am

Take it to the Limit

Post by jdfanmi »

Rich,

I found today that it is an issue of warm start up. I let it idle until temp gauge read 160 F. I shut it off w/ kill switch to check warm compression (135-140 psi). After checking compression I went to restart and it behaved like all of the other times it would not restart. I decided to put a little gas in cylinder. I first put in one cylinder and it sputtered so I tried it in both and it restarted on 3rd pull. Engine was at about 1000 rpm and bogged until I hit the choke (1/2) briefly and then it stabilized. I let idle to let it warm back up and adjusted idle (You can really tell when the timing advances) to approximately 3000 rpm as you recommend. Idle stayed very stable. I picked up the backend to rev it up to see if idle would return to 3000. I let the engine slow itself down and set track back on ground. Idle did not return so I revved it up again by lifting track up but this time slowed track with the hand brake and that seemed to make a differenc. After reving track/engine again and letting it slow w/o brake it was difficult to get it to return to 3000 w/o major bogging and engined eventually stalled and it was time to call it a night. The one thing I have not messed w/ is the air screw other than originally adjusting it 1.5 turns. Could this be causing the idle issue?

Thanks again Rich.

Justin
Mr. Deere
Posts: 3073
Joined: Fri Oct 20, 2006 12:00 am
Location: Rutland, MA

Take it to the Limit

Post by Mr. Deere »

Rich I have the same Problem he does. Make sure your gaskets aren't leaking. Also mine will restart on the first two pulls only then its toast. It major bogs but sometimes it will take right off for like 0 seconds then its back to the bog. BOB
BOB From MASS
OWN: 1 1983 JOHN DEERE LIQUIFIRE 440
1 1973 JOHN DEERE JDX8 440
1 1982 JOHN DEERE SPORTFIRE 440
1 2000 SKIDOO MXZ 600
GOTTA LOVE THAT TWO STROKE SMELL
JDT
Posts: 5561
Joined: Wed Nov 21, 2007 1:00 am
Real Name: Todd
Location: Milbank South Dakota

Take it to the Limit

Post by JDT »

Any chance your primary clutch is intermitantly sticking and not fully disengaging? This can cause the rpm to drop.

And could the failed hill climb be caused by a fuel delivery problem? And also fast take off and then bogging down? Fuel pickup in the tank is too short or too long and as the fuel sloches back it lets the pickup suck air.

Todd
Todd Schrupp

Milbank SD
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