[snowmanofkw]

Hey guys, give me some ideas.....sons 89 jag 340 (with unknown # of miles), when cold, starts, idles fine....runs ok (45-50 mph top), but after its warm, shut it off, and if it sits for say 2-3 min...acts like its flooded....plugs are dry...checked the pump + impulse line they are fine...WOT and 6-7 pulls...and it starts firing again....then rev's right up and idles fine....I did find the strainer in the gas tank separated from the fuel line...will have to replace that, but there is a full line of fuel from the pump to the carb....

And before anyone asks, I have run a compression test (cold) and found it weaker than I would have expected...90 on the pto and 72 on the mag...sound like ring problems to anyone?

 

[brad0199]

Will it stay running after that? Did you try pulling the spark plugs and putting little fuel in to see if it starts right up.I dont know what the compression should be but that dose sound low.And how long will it run before it quits or dose it do it when you shut if off and then try to restart it

 

[CatsN'Doos]

could be your seals. To check the seals take either ether or an unlit propane torch and blow it in on the clutch side. if you have a seal sucking air the propane or ether will raise your rpms (ether will more then the propane) You will want your hand on the kill switch while doing this. Also check carbeurator boots, it may be an air leak in them. Another thing it could be is vapour locking. Next time it does it try throwing snow on the carbs, letting it sit for a minute and trying again. Hopefully this is of some help.

kurt

 

[snowmanofkw]

<div class='quotetop'>QUOTE (brad0199 @ Jan 30 2007, 10:14 PM) <{POST_SNAPBACK}></div>

Will it stay running after that? Did you try pulling the spark plugs and putting little fuel in to see if it starts right up.I dont know what the compression should be but that dose sound low.And how long will it run before it quits or dose it do it when you shut if off and then try to restart it[/b]

hey Brad......it does stay running at idle after that.....it just seems to not be sucking the charged mixture into the crankcase...a little fuel in the cylinders it starts first pull....according to a dealer, it should be in the 120-130 range.
It runs fine after that (for an old girl....)...the other method I found works, is WOT and about 6-7 pulls...then it starts to fire....let go of the throttle back to idle, it almost dies, then feather the throttle...revs right up and idles fione after that....the compression on the mag side is only a max of 72 (cold)....

A buddy is pulling the heads this morning in his heated garage/shop to see what we are into....

 

[brad0199]

Let me know what you find. My guess is compression. I had dirt bikes that would start cold but would not start hot ,have to push them a mile to get started. good luck