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More PE90 questions:

F

FP1201

Well-known member
Changed the plugs to Autolite 386's, cleaned the terminal ends all the D16's were black with one haveing some carbonized oil, but still fireing.

Mag was rebuilt and the impulse is "clicking" the PO went to great lengths to time it @ 28 degrees. The impulse "clicks" about where where it's at now in the picture. I presume TDC is the mark just a little further to the right.

The problem is RPM's and "sputtering" on the trailer you can rev it up to ~2,700 rpm but in the water you can only turn ~2,500 and it seems to spit & sputter, almost like it's starving for fuel, altho ignition can give the same problems...seems somewhere there was a thread or two about timing: of course without a manual it's hard to know the proper specs. and the PE90 should be able to spin the AirProp 66LXL34 to at least 2,800 rpm's

I think the problem is the fuel line: it looks to be 1/4" or maby 5/16"
A new 3/8" fuel line will be installed a soon as one can be fabbed. BTW: The carb is a new, 2V Holly from an AB parts supplier.
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Thats alot of prop for a 90, a 60 30 prop would work wonders for you.Turning 2700 on the trailer and only 2500 on the water don`t make any sense.How are you points and condenser? A bad condenser will cause poping and spitting
 
Joe":chb6hewa said:
Thats alot of prop for a 90, a 60 30 prop would work wonders for you.Turning 2700 on the trailer and only 2500 on the water don`t make any sense.How are you points and condenser? A bad condenser will cause poping and spitting
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FP1201":xkicix1a said:
Changed the plugs to Autolite 386's, cleaned the terminal ends all the D16's were black with one haveing some carbonized oil, but still fireing.

Mag was rebuilt and the impulse is "clicking" the PO went to great lengths to time it @ 28 degrees. The impulse "clicks" about where where it's at now in the picture. I presume TDC is the mark just a little further to the right.

The problem is RPM's and "sputtering" on the trailer you can rev it up to ~2,700 rpm but in the water you can only turn ~2,500 and it seems to spit & sputter, almost like it's starving for fuel, altho ignition can give the same problems...seems somewhere there was a thread or two about timing: of course without a manual it's hard to know the proper specs. and the PE90 should be able to spin the AirProp 66LXL34 to at least 2,800 rpm's

I think the problem is the fuel line: it looks to be 1/4" or maby 5/16"
A new 3/8" fuel line will be installed a soon as one can be fabbed. BTW: The carb is a new, 2V Holly from an AB parts supplier.
ea20c602.jpg

ea20c1f2.jpg

ea20c1dc.jpg

ea20c18e.jpg
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What size holley are you running, a 350cfm or 500cfm. A pe-90 usually runs a 350cfm. In my experience with gpu's you had to change the jetting from factory to get them to run properly, but that is limited to the 500's on 470's.

Larry
 
Larry":xth2c001 said:
What size holley are you running, a 350cfm or 500cfm. A pe-90 usually runs a 350cfm. In my experience with gpu's you had to change the jetting from factory to get them to run properly, but that is limited to the 500's on 470's.

Larry
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IIRC the carb came from Hoffman, and was ordered/set-up specifically for the PE90
Inside and out it looks brand new.
Condensers are said to get weak with age....this boat has sat un-used for better than three years, but was well cared for when it was being used. that said, I still haven't burned a full tank of fuel thru it yet.

"If it ain't broke, figure out why". :p

.Turning 2700 on the trailer and only 2500 on the water don`t make any sense
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On the trailer it's only being accelerated to peak RPM and let off, on the water WOT is lasting longer and if there's insufficient fuel delivered to the carb it'll die-catch-die-catch very rapidly. (I think) If you hammer it, then let up a little it doesn't seem to do it as much if all, problem is now it's down to ~2K and this boat needs a little more speed in deep water (It's very heavy, especially with 1/2" poly on the bottom.

Maby I'll place indexing marks on the mag/case and try advanceing it a little at a time to see if there's an improvement.

It's kinda a hard problem to diagnose becasue it only occures at WOT....time and prior experience will certainly solve it. :wink:
 
I had a similar problem with my PE-90. After talking to chester at J&C airboats I found out that a PE-90 is not actually 150 H.P. They are only around 118. I ended up putting a 66x32 and had the hub drilled out to an LXL pattern and then it would turn up properly.
 
Pulled the fuel line: at the pump there is a 3/8" pipe (pump outlet) to #6 JIC elbow:
on the end of the elbow is a #6 to #4 JIC reducer:
#4 female JIC fitting on 1/4" braded hose (original for the 1V carb) and on the other end #4 JIC adapted to 5/16" rubber hose that's pushed on and clamped to a piece of 5/16" steel brake line that feeds that 500cfm Holly carb!

Won't be 100% sure until another line if made, but it's hard to believe that 1/4" line would carry enough fuel at WOT to feed the carb sufficiently, plus the #4 JIC is really restricted to ~3/16" thru the fitting.
Enough fuel doing a quick run-up and let-off on the trailer, but on the water where the duration is longer, it's gotta be starveing....right?

....They are only around 118. I ended up putting a 66x32 and had the hub drilled out to an LXL pattern and then it would turn up properly.
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I sure hope this engine will turn the 66LXL34 that's on it. Not sure of the max RPM on this prop, but the max on my Sensenich 66LML36 is 2,880. (per Sensenich)
I have an old Kirkland prop in 66LML36 that I was going to drill & try (it was a spair from my Dad's old boat) and if it worked out, drill the Sensenich and run it (it was rebuilt decades ago and put away...ironically my Uncle ran the 66x36 on his 125 Lycoming and it seemed to do alright, but what does a bug-eyed kid really know other that it's loud and FUN!
 
Have you considered your fuel pump? Since you haven't mentioned it, I reckon' you're using the mechanical that's mounted on the accessory case. If so, I'd guess that it should be alright, though I've heard stories of 'em not providing sufficient pressure after age.

My 220 only has an electrical fuel pump. After the original one smoked (5 miles out in the 'Glades, without a replacement....but that's another story), I bought two Carter fuel pumps (one as a spare!!!). This fuel pump is a continuous flow pump, which means it's still running even after the pressure has built up. Haven't had any fuel pressure issues with it.

My buddy's 220 does the same as yours......at top end, it starts to sputter. Maybe once he get's it back in the water, we'll figure out what it is and post our findings.

Good luck.......
 
midnight rider":2hj1w7fv said:
I had a similar problem with my PE-90. After talking to chester at J&C airboats I found out that a PE-90 is not actually 150 H.P. They are only around 118. I ended up putting a 66x32 and had the hub drilled out to an LXL pattern and then it would turn up properly.
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Your saying 118hp...At how muchRPM?
 
Hadn't really considered the fuel pump, but it seems to do the job. Changed out the fuel line and did away with all the cobbed-together stuff and it was 1/4" line. By comparison, the fuel line on a Ford 302 with a 2V carb has a 5/16" line, most 4V setups use a 3/8" line. The PE90 is ~315 inches with a comaparable carb....tomorrow we'll see what it does on the water. 8)
 
FP1201":381xt0mq said:
Hadn't really considered the fuel pump, but it seems to do the job. Changed out the fuel line and did away with all the cobbed-together stuff and it was 1/4" line. By comparison, the fuel line on a Ford 302 with a 2V carb has a 5/16" line, most 4V setups use a 3/8" line. The PE90 is ~315 inches with a comaparable carb....tomorrow we'll see what it does on the water. 8)
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Still sputters a little at WOT and 2,400~2,500 is max.
a pressure gauge on the fuel line shows 4~5 psi at 500rpm
Put some 100LL in it today, and we'll give that a try.
Maby pulling the cap and checking for carbon tracking/moisture and the wires will be next.
Maby that's all it's going to do....time, trial, and error will tell! :?
 
Mine was doing the same thing. It would run fine, then when I stepped on it, it would sputter at top end. Turning 2600RPM with a 68x34 sensenich stick. It was also using a lot of oil, so I found another PE 90, still in the generator unit, that had a recent overhaul (government overhaul - .010 over). I put that thing on the boat and the difference was night and day. Could turn the same prop to 2800 RPM, and did not sputter at all. Hardly uses any oil. Still running the same engine.

Would "blow by" cause this problem? Or maybe a magneto/timing issue?

Let us know what you find out.

Brent
 
AirAg,
I sure would like to find one still in the generator! Do you have any details on the Gen unit itself? or engine data plates? National Stock Number? .....? If it ever belonged to Uncle Sam, there's a manual for it and chances are a copy can be had, just have to know "what" it was classified as.
Three or four hundered RPM doesn't sound like much, but it is. :wink:
 
I have never found a used motor with a good magneto. I recommend having the magneto rebuilt by a quality shop. The previous owner of my 220 GPU showed me how to handle the starting problem on the carburetor because it would flood easily after it was warm. He even had a fuel shut off to help start it. I took the mag off and had it rebuilt and all my carburetor problems went away. It never was the carb. Once the magneto is rebuilt and the timing set right, you know that is no longer the problem.

The mags should to be rebuilt first and then look at carburetor problems. This would be a good time to put on a new set of plug wires too. Mike Thurman has the best and the price is very reasonable. Arn-air in Bayard, Iowa is a FAA Certified shop where I get mine repaired. Fast turn around and easy on the wallet.
 
My 220 was doing the same thing.It would almost seem like you had a dead pedal.It got worse when the motor was hot and it would spit and sputter.Changed the fuel pump rebuilt the carb,and changed the filter.It turned out to be the condenser.
 
As others have indicated, I am so inclined to believe that the Magneto, specifically the condenser might be the culpret, and/or carbon arcing. Haveing never been into a AC mag I'm a little gunshy about pulling it off and opening it up. Hopefully it isn't any more difficult than one off a IH Farm-All tractor. (it wasn't all that complicated, and it was has an impulse coupling)
Reccomendatons for parts? (it's a Slick Mag.)
Tips & tricks?
Everything is well marked so all should go back on and time if properly removed. :shock:
 
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