the good and the bad, first ac engine.

Aircraft powered airboat discussion.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

the good and the bad, first ac engine.

Post by MoreSht »

New to ac engine, new to forum. just purchased, sight unseen except for pic., 14’ stossel w 6 cylinder (540 ??) plus extras..... pause for a$$ whipping and laughter......... (take all the time you need before moving forward, be gentle). Like help figuring what i have, and how to get it up and in usable, dependable shape, hasnt been used for over two years. Moving forward,,,,,checking it out. All stainless rigging, (raised driver seat front single passanger behind). No visible cracks, motor mounts , etc all look good. Tank full of av gas (blue), ran some thru to container, small amount of water, cleared right up. Was going to drain and clean tank, but looks like i have to remove seat stand....not.... Ok, new filter, add sea foam (can i use sea foam), inspect hoses,,,, fuel good. Two blade water walker prop, ( extras, 4 used blades + one new, + hub), leading edge great except right below metal, slight wear. New battery, fuel pump works. Prop turns, sounds good, pull plug, got spark,,,,, First air boat carb, where is it??? So cleaned carb, accelerater pump stuck, cleaned, reinstalled. (memo-get carb kit). Reading forums (thanks everyone), think i have an updraft d4-5? Does that sound right. Pic comming. Pull plugs, clean plugs, bottom look like sh-t. Add oil to threads, replace. Crank..... Running ac engine :cheers: . Sorry for the long drawn out bs. this is where your wealth of knowledge comes in. i need to know what i have and to get it running correctly. Tag on oil pan indicates IO 540 d .....great, right, 260hp etc...
8CEFFBA0-C42C-46C6-9717-97A8D021B9B6.jpeg
46266534-BBF8-4FD9-9CED-AC03C74CC826.jpeg
9884CFF8-BFDF-4AAF-9576-A9A81FB175CC.jpeg
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Day two.... Drop in water at camp, oil pressure 60 and up, temp 140, alt 14v but belt squealing. After warm up, rpm max 2100, spring pull on carb to loose, wont idle down. Slight difference in rpm shutting down each mag. What mags ???
FC0F7475-DE8C-419C-9D53-92E9EB962F1F.jpeg
Some white smoke on starboard side exaust. Replace spring, adjust accelerator arm (remember i cleaned carb, my fault) so it can open all the way. Ran, Max rpm 2400. Shutting down mags dosnt shut of engine now. Difference in mags, left shut off drops 300 rpm at 1500, right shut off no difference, both shut off, runs like with right only on. Replace mag switch, same,,, disconnect wire at right mag,,, no difference, still runs dropping 150+ rpm at idle, left mag on, runs good. Clean and gap plugs, swap top to bottom (champion 16, bottom .015 top .018, choice after reading forums, thanks), thinking i may have bad plug for rpm difference, gain 100 rpm to 2500. Go crussing on lake for an hour, hoping it will fix itself....Any ideas??? Will get new plugs when i go to town. My thoughts.... right mag not working, but why does it still run??? Remember extra parts :cheers: :cheers: :cheers:
F9C6C51C-B5B6-4C22-BE59-A8ED1C1A3510.jpeg
2BC08532-21C7-497A-98A8-50794548FCEF.jpeg
Have three extra mags in pieces. On boat, left mag does left (port) top and right bottom, right, does right top left bottom. Is that normal. Will try tracking down fireing order and trace wires, is #1 cylinder closest to prop??? Remember ignorance isn’t stupidity, be kind. Thanks
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Day 3. Still talking to myself.
5B33453E-AB8E-40C4-88C5-A072353ACE5E.png
Thanks forum, found pic of firing order and plug wire diagram. Checked mine, looks good. Mag next, here are some pictures.
127F78BC-CD64-409A-A219-8958EE86BD80.jpeg
916C102A-54AF-4635-8CE8-585473CC8A4D.jpeg
KC 0540
Southern Airboat Member
Posts: 5
Joined: Mon Jan 28, 2008 10:19 am
Location: Alva Fl

Re: the good and the bad, first ac engine.

Post by KC 0540 »

Right mag is not grounded. Mag switches ground to motor when off. Try connecting a jumper wire from mag and running motor without it grounded then ground to motor. that should kill the mag and you should have a mag drop if the mag is good. Make sure you have a long enough wire so you can do without getting hands close to prop. Your mag switch could be bad also and this will tell you that also. Good luck.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Thanks KC. Replaced switch day two, when it went from toggle switch to rotary switch (bad). With new switch did same thing. With your advise, i went down to boat with wire to ground mag and decided to track down switch wires. Seems I pulled one of the wires putting new switch in. Thanks, it let me know what to look for. Ever feel like you are, your worst enemy. :banghead: :banghead: Both mags off, engine off. Either mag on difference of 150 rpm at 1500rpm. Is that acceptable? Idle set between 400-500 rpm. Does that sound right. Figured why alternator quit squeeling.... (remember, came with extra parts). :cheers: :cheers:
2AB511A7-1B7A-4B88-8591-14121FE09312.jpeg
.
fl cracker
Site Supporter - II
Site Supporter - II
Posts: 4050
Joined: Thu Aug 20, 2009 9:15 pm
Location: Sorrento,FL

Re: the good and the bad, first ac engine.

Post by fl cracker »

The mag drop should be around 50 to 75 Rpm between the 2 . Plugs on the bottom look bad due to Rings OR its been sitting a while . The white smoke show oil burning. I would bump the idle up to 600 -650 , they don't like to idle for too long .
" I have two guns...
One for each of you "

2011 Al David / AV 540
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Thanks, fl cracker. It’s been sitting for two years, so I think i’ll take it to the coast and run the flats for a few days, loosen everything up, then check compression and put the new plugs in (along with keeping fingers crossed). See if that helps rpm difference. Idle 600-650, easy enough. It has 2 blade water walker prop along with 5 extra blades and another hub. My final goal is to get the rpm and whatever else right so it will go dry. Can the 14’ stossel with poly, 540d and that prop do it? Previous owners said it could, but i havent seen it yet.
User avatar
Slidin Gator
Site Supporter - IV
Site Supporter - IV
Posts: 1271
Joined: Sat Feb 03, 2018 11:33 pm
Location: Jupiter Farms, Florida

Re: the good and the bad, first ac engine.

Post by Slidin Gator »

MoreSht wrote:
Mon Oct 11, 2021 5:06 pm
Can the 14’ stossel with poly, 540d and that prop do it? Previous owners said it could, but i havent seen it yet.
Yes, mine does. Put some CHT (cylinder head temp) sensors on middle two jugs and you will probably want a cooling shroud.

On the mag drop test, specs call for test at 2,100 - 2,200 RPM. Maximum drop of 175 RPM each and no more than 50 RPM difference.

Manuals are available here. What kind on nuts are used to hold the cylinder to the crankcase? Regular hex nuts or special Allen head nuts?
https://www.southernairboat.com/pdf/ai ... oming/540/
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.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Will do mag drop test tomorrow before i run the boat, then after it is run and i put new plugs in. Will take pic of cylinder bolts tomorrow, but remember looking at them thinking there wasnt much room to get in there. The outer ones are star bit and the others are allen bit. There is also a plate below them. I take it these are narrow flange. Also in spare parts, :cheers: have rebuilt wide flange in box. Are allen bolts good or bad, or what significance? :scratch: Thanks.
User avatar
John Fenner
Southern Airboat Member
Posts: 2951
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: the good and the bad, first ac engine.

Post by John Fenner »

Bear in mind that Lycoming engines have the camshaft in the roof of the case, when shut down hot, oil drips away from tappets and once cool down begins, evaporate builds in roof of case, that moisture collects on the tappet faces, causes rust spots, which turn into spalling "pitting" in which will wear the camshaft in due time, sitting for 2 years in who knows what environment, winters, hot summers then rain to cool things down quick drawing in more moisture, I suggest putting some hours on it, pull the filter, cut open and inspect for metal, oil sample test at an aviation shop, if metal found, tear it down for inspection, replace tappets, likely cam as well, while apart, freshen up valve job, and many other tricks to make it more powerful.
I never finish anyth,,,.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Gator, did the mag drop test. At 2100 rpm each droped right at 175 with no difference between the two. They only had 8 plugs, others will be in tomorrow. Will change plugs do compression test, then run and do mag drop again. Bad picture, but they are allen head.
8376C531-8982-460C-97B8-F07215DCA82E.png
John, thanks for the info. I have no knowledge of the engine hours etc... It was a tp&w boat. I did talk to the guy that worked on it and he said it was hard to keep them going with 7 or 8 different people using it (the bad). :violent1: The GOOD, :cheers: came with another engine with stand. He said it had been rebuilt and was ready to go, just add accessories.
88AAB7BD-D675-4D92-A972-6122D3379176.jpeg
Also came with another carb, prop blades and hub, 10+ starters, 3 mags, belts etc... Looks like all it is missing is bottom motor mounts and starter mount.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

There is “ a bad” that i havent brought up yet. Trying to ignore it and see how bad it is.
The “GOODS”. Extra parts, extra engine, stainless rigging.
The rig has plenty of power on the water with my cruise between 1500 rpm to 1800rpm.
Love sitting up front where i can see in water. (like my first dd 350 panther)
Purrs at 600rpm idle. (thanks cracker)
the “Bad”. Top rpm 2500rpm. (we are working on that)
Not to impressed with the single large air foil/rudder in high winds. (can live with it)
The accelarator needs to be moved farther away from my long legs. (easy fix)
No where near dry ground ready. (Start by fixing the 2500 rpm issue

Thanks, with your help, and knowledge, maybe we can get this on dry ground and improve the learning curve on my ignorance.
User avatar
Slidin Gator
Site Supporter - IV
Site Supporter - IV
Posts: 1271
Joined: Sat Feb 03, 2018 11:33 pm
Location: Jupiter Farms, Florida

Re: the good and the bad, first ac engine.

Post by Slidin Gator »

Stand by on your judgement of the rudder until you get that rig into the nasty dry. No doubt it can be a handful on the water in a side wind, that’s the price of admission. But you will be amazed at how that rudder works on ground, that’s where these boats show their stuff.

Does the rudder have a trim tab? If not, add one to fine tune the rudder. Without a side wind I can take my hand off the rudder stick, tighten my hat and mash the gas, all at the same time. Tuning the trim tab makes a huge (and I do mean huge) difference in the rudder feel. I bent the tab on a bush one time and damn near sunk when I hit the water, it took all I had to fight the rudder. Turned around to get back on ground and sorted the tab right out.

If it turns out you don’t like it, drop me a PM, I’ll buy it to add to my spare rudder stash.

Narrow deck engines are older, usually 1960’s era. Cylinders are harder to get, but it looks like you have that issue solved. Otherwise you have the lightest 540 motor. The narrow deck just requires the right tools, otherwise they are good motors for sure.

I think this thread will have lots of info you can use.

https://southernairboat.com/phpBB3/vie ... hp?t=72194
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.
Gary S
Site Supporter - I
Site Supporter - I
Posts: 1798
Joined: Wed Mar 03, 2010 3:30 pm
Location: Redlands

Re: the good and the bad, first ac engine.

Post by Gary S »

What's a tp&w?
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4658
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: the good and the bad, first ac engine.

Post by Deano »

Gary S wrote:
Wed Oct 13, 2021 6:43 am
What's a tp&w?
I'm guessing that it is Texas' version of our FWC.
Texas Parks & Wildlife ?

MoreSht, Sounds like you got a hell of a deal, Congratulations !
We appreciate you [Searching] the forum in an effort to help yourself before burying us
with questions that have already been answered a hundred times; many people do not. :cheers:
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4658
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: the good and the bad, first ac engine.

Post by Deano »

MoreSht wrote:
Tue Oct 12, 2021 3:11 pm
There is “ a bad” that i havent brought up yet. Trying to ignore it and see how bad it is.
the “Bad” --> Top rpm 2500rpm. (we are working on that)
Given the history/back ground the boat (and its multiple operators), I would expect there is a distinct possibility (if not likelihood) that it was over-pitched quite deliberately to limit the top end speed. After you confirm everything else is according to Hoyle, you may find taking out a little pitch will get it closer to where you were expecting it to be.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Sorry, Gary, Deano is right. The boat came from texas parks and wildlife out of Port Arthor. They said it had no problem jumping the ground between impoundwents (still has soap tank and nozzles under bow but no plumming). They got new boat 2 years ago and this one has been sitting since and came with extra parts, and rebuilt (???) engine. Deano, when i picked the boat up, I talked to as many employees as I could to learn about boat and they all said it would go over their levies. I am trying to eliminate as much as possible as to why it cant run damp grass now. I am leaning to John Fenner’s post warning of damage fron two years of non-use, thus only reaching 2500 rpm. The way i figure, it can be a cylinder not working (all get hot quick), worn engine, etc.. (will do compression test, and run, then check filter like john suggests), or too much prop. The pitch dosnt make sense if they were running dry and needed too, unless it was altered, like to change alternator belt (like i have to). This engine if i remember reading correctly, should produces 260hp at 2700rpm, and 195 hp at 2475 rpm. My thoughts are, get that 65 extra hp and watch out gophers. :bounce: Is it the engine? The prop? What else could it be. ps. deno, goes plenty fast and starts to porpoise. Figure that out later. Thanks, and keep suggestions coming. :usa:
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4658
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: the good and the bad, first ac engine.

Post by Deano »

Understood. That is exactly why I eluded to AFTER you confirmed there wasn't an additional issue(s).
I have seen that exact scenario played out here in the past, and is the reason I mentioned it.
Given the additional storyboard, that same scenario does seem unlikely.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Paper work going on right now. (Taxes, no more extensions). :banghead: :banghead: Wont get back to boat till friday. Have to pull prop to put new alternator belt on, but figured to do compression test, change plugs, anything else suggested before mess with prop to see if i can get the rpm up. If the prop was over pitched, part of me wants to think it would move on ground easier. But without that extra rpm to get the hp up, I can see why it cant. I dont see them changing the pitch of the prop for no reason. Not my kind of luck. Other thought is :scratch: is carb opening all the way? Will accelerator pump weak cause low rpm, yet response and speed be good. Remember, i just cleaned carb, didnt rebuild, and accelerator pump looked pretty bad.
Gary S
Site Supporter - I
Site Supporter - I
Posts: 1798
Joined: Wed Mar 03, 2010 3:30 pm
Location: Redlands

Re: the good and the bad, first ac engine.

Post by Gary S »

Accelerator pump not being up to par won't kill wide open throttle, only how fast it gets there. It can also make it hard to crank cold. I saw a boat with a 180 on it that was thought to be wore out and it ended up being throttle wasn't opening all the way. You might be on to something and easy to check and fix.
You defiantly hit the honey hole with this boat. You get it at auction?
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Thanks, gary. It is hard to start cold. Air moves easier than water, can i do full throtle on trailer hooked to truck with extra tie downs while i play with carb and someone watches rpm gage and get true rpm? I have won sevveral beers 30+ years ago with my dd 350 panther pushing truck and trailer down road at 30+ mph, just took time and beer to get there. Yea, got at auction sight unseen, but talked on phone to person in charge and got as much info as possible with him doing walk around while on phone. There’s a “BAD” :violent1: on boat i dont want to get into yet, it would of changed how high i bid. The “good”, :cheers: didnt know about extra parts (did know about extra engine). In extra parts (still in box) is rebuilt cylinder, think they call it a wide deck and almost all pieces to complete extra engine (prop hub and blades carb,starter, alt, etc... As far as hitting honey hole (around 9K), too early to tell. :dontknow:
User avatar
John Fenner
Southern Airboat Member
Posts: 2951
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: the good and the bad, first ac engine.

Post by John Fenner »

Ok, another thing, use search engine on this site, being that it has sat in unknown conditions, yes do compression test, then if you locate a wheezy cylinder, search how to do leakdown test, I just use my compression gauge adapter hose with the Schrader valve removed, if compressed air is leaking past a valve, you know which jug needs repair, STAY CLEAR OF PROP!!!!! There is most likely rust pits in the valve seats that the valves were open during the 2 year slumber, intake valve leaking causes reversion into induction, exhaust side will just lack compression
I never finish anyth,,,.
MoreSht
Southern Airboat Member
Posts: 31
Joined: Mon Oct 11, 2021 5:31 am
Location: south texas

Re: the good and the bad, first ac engine.

Post by MoreSht »

Will do John. Been reading on leak down test, sounds simple enough. Harbor freight has two, a better one (not pittsburgh) that has 18mm adapter with it, and good reviews. “””intake valve leaking causes reversion into induction”””. Does that mean intake issues will be more likely to be seen on leak down test, where exhaust more likely to be seen on compression test? Thanks.
Bamasoflorunner
Southern Airboat Member
Posts: 74
Joined: Wed Nov 13, 2019 6:34 pm

Re: the good and the bad, first ac engine.

Post by Bamasoflorunner »

Question on the spare motor. Does it have the same carb? If so swap it see how that one works. Question 2. You wanna sell spare motor? 😂😎 Another easy check is take a IR thermometer put on exhaust flanges at idle warmed and check temps, if one is severely off on temp gonna have issues with that cylinder, how I found mine before getting crazy taking apart etc.
User avatar
Slidin Gator
Site Supporter - IV
Site Supporter - IV
Posts: 1271
Joined: Sat Feb 03, 2018 11:33 pm
Location: Jupiter Farms, Florida

Re: the good and the bad, first ac engine.

Post by Slidin Gator »

Compression test is essentially a pass/fail health check. A leak down test accomplishes the same goal plus the ability to pinpoint the problem. They both take about the same time.

The Harbor freight kit works fine. It’s not calibrated like an aviation setup to the specific engine, but it gets the job done.
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.
Post Reply

Return to “Aircraft Power Only”