My son bought a $100 Jag, won't pump fuel

K

KKRRSS

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Dec 31, 2012

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Burley, Idaho

• Nov 18, 2013

• #1

My son wanted a sled project, so he bought a $100 Arctic Cat Jag 3000 F/C.

We:

Pulled the plugs, checked compression, GOOD.
Verified spark, GOOD.
Pulled the carb, disassembed and cleaned in a can of berryman's, GOOD.
Cleaned fuel tank, GOOD.

Tried to get it to pump fuel, but it wouldn't.
So, pulled the fuel pump, was gummed up.

Disassembled the pump and dropped into the can of berryman's.
Rebuilt with new diaphram.

Still won't pump fuel.

Replaced impulse line with the blue snowmobile tygon fuel line, no change.
Removed carb fuel line to see if needle/seat stuck, no change.
Tried a new piece of fuel supply line directly into the tank (bypassing the in-tank line), no change.

I took apart the pump and it looks right, everything is clean, and the diaphrams line up correctly (I am fairly certain).

Tried hooking up my vacuum gauge to the impulse line, needle never moved.

I am at a loss, what else can I check?

Thank you,
KKRRSS

 

89sandman

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• Nov 18, 2013

• #2

i'd mix a little fuel, pull the plugs and dump a little in each cylinder and fire it that way a couple of times and see what happens.

 

m8magicandmystery

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• Nov 18, 2013

• #3

your pump depends on crankcase vacuum..you can simulate it with your mouth with the vacuum line to see if it pumps and as sandman says see if it fires with a bit of gas poured in the cylinders...but I suspect a crankcase outer seal torn so you have no crankcase vacuum and its generally always the clutch side..(belt cords wrap around back of primary when belt expodes and damages seal..)

the seal on those old sleds might be able to be replaced by removing the primary and picking the old one out and hammering a new one in without much problems but im not sure if that sled is that easy..

 

Last edited: Nov 19, 2013

K

KKRRSS

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Dec 31, 2012

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Burley, Idaho

• Nov 23, 2013

• #4

Well, took your advice and sprayed some fuel, it appears to be pumping!

It would pop and run a cycle or three, but wouldn't really run.

Noticed exhaust fumes coming from a seal in the engine housing down between the mag side jug and the cooling fan.

When we pull it over and it pops, that little gap fills up with exhaust and we can't verify for sure it's coming from there, but I am fairly certain.

We pulled the motor out.

I made a video of the location I am writing about:
http://youtu.be/pvCBc8ECbaw

Please any help would be appreciated,
KRS

 

m8magicandmystery

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• Nov 23, 2013

• #5

hmmm...seal or jug base gasket..??

 

K

KKRRSS

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Burley, Idaho

• Nov 23, 2013

• #6

Not jug seal

 

m8magicandmystery

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• Nov 23, 2013

• #7

well then it can only likely be either seal failure or fan belt smoking on that side with oil etc..??..

it strange that you say it would pop and not really run when you sprayed the fuel as it should have fired up decently with some rpm for a few seconds...maybe a timing issue..??...that's a cdi ignition..??

 

m8magicandmystery

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• Nov 23, 2013

• #8

maybe you have a mouse nest in your exhaust..

 

K

KKRRSS

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Burley, Idaho

• Nov 24, 2013

• #9

pulled exhaust can to rule out mouse nest, no change.

Will run a wire up the Y pipe to check that out.

Never gains RPM, just pops real slow a few times, with a bit of exhaust fumes coming out of carb, and lots coming from that MAG size jug area.

Pulled motor, going to mount it up to something, and try again outside in the sun and take a video to see if that helps with diagnosis.

Really appreciate the help, thank you for replies.

 

m8magicandmystery

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• Nov 24, 2013

• #10

that engine have reeds..??..

 

joshkoltes

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• Nov 26, 2013

• #11

Pour the gas down the cyl to get it going then quickly before it dies spray either on the crank seals. If it revs up there's your leak

 

K

KKRRSS

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Burley, Idaho

• Nov 26, 2013

• #12

Set it up on a stand, tried to get it to start, but wouldn't pump fuel.

So, used my mouth on impulse line, and it pumps lots of fuel.

There just isn't any impulse.

I am a rookie, but I think that must be a seal in the bottom of the motor.

I am ready to wrench, just need help.
KRS

 

m8magicandmystery

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• Nov 26, 2013

• #13

you may be able to pick the old seals out and install the new seals without splitting the case or anything drastic..its just that im not sure but I know on many old motors the seals pop in and out easy...just remove the primary and flywheel...but someone for certain could chime in or you could download a shop manual from tradebit site..