1980 Intruder Shake Down not going well

[mswyka]

Last year we put together a 1980 Intruder.  It all went together well, and with what little snow we had it seemed to work OK.

Getting it out of the machine shed this year it quit half-way home which turned out to be a cracked primer feed line.

On that trip I don't believe the sled ever broke 20 mph but was spinning 5000 RPM or better and showing 50 mph on the speedometer.  Replaced the frozen secondary and swapped in a different speedometer adaptor and the operation improved dramatically.

Last week I thought I had the carbs dialed in to idle nicely.  Today we had a little snow so it was time for a little more testing. While it would not idle, early running was better than the day it came out of storage, but not great.  Checking temps, the pto cylinder was close to 300 while the mag cylinder was less than half this value.  exhaust on the pto was 400 ish, exhaust on the mag side was 200 ish - all measured with infrared pyrometer after sled was stopped and I had gone into the garage to get the gauge.

Pulled the Mag plug which was very wet.  Swapped in a new plug and she seemed to respond better - still not idling.  Went for a spin, had a few good pulls, but the power seemed to be increasing and decreasing randomly.  Came back to the house where she lost power, and then died, and is currently sitting.

Thoughts?

[Interceptor398]

Is the mag side plug wet again?

[mswyka]

Is the mag side plug wet again?

I will check.  I had some other things to do, so I have let it sit.  I will check it now.

[mswyka]

Plug did not look particularly wet.  However I now have a new development.  After checking the plug I added fuel and then started the sled, pushed the idle up a bit more, she sat there idling nicely, so I decided to go off across the yard.  Ran strong at first but by the time we got to the mailbox sh bogged and died.  Now it will start on a prime, but will not stay running.  Sounds like I will need to check the fuel delivery system.

[Interceptor398]

Pick up line in the tank can act like that??

[Boomologist]

Plugged fuel filter?
Vacuum line to fuel pump kinked, leaky or broken?
Fuel pump not working right?
Water/crud in tank?
 

[mswyka]

Rechecked all the lines this evening.  All were new last winter and still looked  to be in good shape and had nice smooth bends.  Fuel filter still looks new.

Checked compression.  Highest value I have ever seen on one of these sleds.

Mag side carb had a stiff float lever.  Pulled apart and reamed hole so that it would move freely.

Checked fuel pressure and measured 2 psi.  Sounds low.  Swapped in a different pump.  Started and pumped fuel but sled would not idle.  Needs more work.

Got late so no further testing.

[mswyka]

This evening tried again.  On a prime the sled will start and run.  Idle is somewhere between 2500 and 2800.  It will sit for 15 or 20 seconds then die and need to be primed again to start. 

If I hold the rpms at 3000 it will stay running.

I find this very odd as it ran fine when we put it away last season.

oddly enough the fuel filter does not appear to have fuel in it.  And we have a couple of air bubbles in the fuel lines that don't seem to be working themselves out.  We were sucking air at the primer, but changed the primer and the primer lines.

[Interceptor398]

The primers themselves will leak air.  Start the sled and squirt something that will make bubbles on the shaft of the primer and look for bubbles.  Been there done that!!

[mswyka]

The primers themselves will leak air.  Start the sled and squirt something that will make bubbles on the shaft of the primer and look for bubbles.  Been there done that!!

Will do.

[mswyka]

Got it. Blocked pilot passage.