steepndeep

Rebuilding last machine (1989 Indy 500) for the grandkids. I have stripped everything down and gone through everything. Tore carbs down and cleaned all passages, jets, needles. Dropped engine in this past weekend and fired it up. Starts and runs only on one cylinder (mag side). I have good spark, good compression and fuel to both cylinders. When I pull on the choke cable going to the cylinder that's not firing it then fires up and runs as long as I'm keeping rpms up. I sprayed WD40 around pto seal but that didn't affect anything. I then swapped carbs, leaving fuel and choke lines and cables attached and the problem does not follow the carb. Any suggestions would be appreciated.

RJ Gleason

Go back through the carbs and pay particular attention to the pilot jet [up the tube] and floss it to ensure that it is clear.

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'90 Wildcat Project in progress.

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steepndeep

I have done that and the problem does not follow the carb (I kept fuel line and choke hooked to the same carb when switched) but stays with that particular cylinder.

RJ Gleason

It wouldn't happen to be the cylinder that the fuel pump pulse line is attached to would it?
If so, then you might want to consider a rebuild of the pump.

Sent from my DROID X2 using Snowmobile.com App

__________________
Old Cat Rider
'93 Wildcat 700EFI
w/ Comet 108 Pro-4 clutch & 01 ZR skid

'90 Wildcat Project in progress.

Vintage (sorta)
1980 Indy Trail 440 (for sale)
1980 AC Pantera (donor engine to the 90 wildcat)


http://www.dcdrifters.net/


Senior Warden; F&AM Dryden Lodge# 472
http://www.masonicdryden472.org/

Rules of this forum are strictly enforced!

smallengineguy

Or a compression test of that cylinder.

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steepndeep

It is the cylinder that the impulse line goes to and I did check the compression (125 psi/cylinder). If it were the fuel pump, why would the problem only be on one cylinder and not follow the carb (left choke cable, throttle cable and fuel lines attched) when I swapped them?

RJ Gleason

Because the pump is leaking and excess gas is going into the cylinder through the base by way of the pulse line.
Get a pump rebuild kit and that will solve the problem.

__________________
Old Cat Rider
'93 Wildcat 700EFI
w/ Comet 108 Pro-4 clutch & 01 ZR skid

'90 Wildcat Project in progress.

Vintage (sorta)
1980 Indy Trail 440 (for sale)
1980 AC Pantera (donor engine to the 90 wildcat)


http://www.dcdrifters.net/


Senior Warden; F&AM Dryden Lodge# 472
http://www.masonicdryden472.org/

Rules of this forum are strictly enforced!

steepndeep

If the cylinder were getting too much gas, then pulling up on that cylinder's choke cable should not cause that cylinder to start firing, would it?