Gpu220 losing power at full throttle

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
Post Reply
walkertime1995
Southern Airboat Member
Posts: 3
Joined: Thu Sep 27, 2018 2:24 pm

Gpu220 losing power at full throttle

Post by walkertime1995 »

Both me and my dad have gpu220 with Holley 500 2 barrel.
Both doing the same thing. At WOT it starts to lose power after about 5-10 seconds. Have electronics fuel pump and pressure seems to be good. What can be cause the loss of power?

User avatar
kwanjangnihm
Site Supporter - IV
Site Supporter - IV
Posts: 2101
Joined: Sat Mar 30, 2013 8:23 pm
Location: Bartow FL

Re: Gpu220 losing power at full throttle

Post by kwanjangnihm »

walkertime1995 welcome to SA!

here is a great link with things to check on! hope this helps :thumbleft:

viewtopic.php?f=47&t=69917&hilit=holley+wot
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

walkertime1995
Southern Airboat Member
Posts: 3
Joined: Thu Sep 27, 2018 2:24 pm

Re: Gpu220 losing power at full throttle

Post by walkertime1995 »

I appreciate it. I will check it out.

User avatar
John Fenner
Southern Airboat Member
Posts: 2894
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: Gpu220 losing power at full throttle

Post by John Fenner »

Remove the scintered bronze filter in the bowl inlet.
I never finish anyth,,,.

walkertime1995
Southern Airboat Member
Posts: 3
Joined: Thu Sep 27, 2018 2:24 pm

Re: Gpu220 losing power at full throttle

Post by walkertime1995 »

I don’t see any type of filter on mine. Where would it be located or do you have a picture of what I should be looking for

gpu rick
Southern Airboat Member
Posts: 140
Joined: Tue Nov 07, 2006 9:59 am
Location: ocala
Contact:

Re: Gpu220 losing power at full throttle

Post by gpu rick »

It could be many things. I would check your magneto check to see If you have carbon tracking in your terminal block your mag could be shorting out. This is a common thing in aircraft engines that lose power at higher rpm. Had a lot of people bring there gpu's in to fix and they think its the carb and its not.

User avatar
Slidin Gator
Site Supporter - IV
Site Supporter - IV
Posts: 964
Joined: Sat Feb 03, 2018 11:33 pm
Location: Jupiter Farms, Florida

Re: Gpu220 losing power at full throttle

Post by Slidin Gator »

A clogged fuel inlet filter is the best match to the symptoms described. I run Quadrajets but it is the same symptom. A clogged inlet filter will restrict the flow, the bowl will stay full at idle and part throttle, but at full throttle it won't let enough fuel through to keep the bowl filled. So you get max performance for a few seconds, then WTF. 2 boats (same owner) showing the same symptoms makes for a stronger case that this is the issue. Just change them every year you will look at the filter and not see any trash, but swap it and all is good.

I agree with John that removing it is a good trouble shooting move, but I dis-agree with removing it and leaving it out because the next problem is a piece of rubber etc. in a jet where it is harder to diagnose. Go buy 3 (per boat) at the parts store, swap one, keep one for spare and plan to sell the 3rd for $30 in the woods.

The filter in question will be inside the fuel connection on the carb, break out the 12" crescent.

Image
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.

User avatar
John Fenner
Southern Airboat Member
Posts: 2894
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: Gpu220 losing power at full throttle

Post by John Fenner »

I like to run a purolator inline pre filter, the glass type that has the replacement element, vs the inlet filter in the bowl, you can see the trash buildup to know the water separator needs replacing.
I never finish anyth,,,.

Post Reply

Return to “Airboat Tech”