Search found 1132 matches

by GMAC 76
Thu Feb 08, 2018 9:45 am
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

is the lean/rich assembly working properly and has the economizer been adjusted...ya have to tweek things like that when ya put a carb on an engine that it wasn't built for...there might be something to that crossover tube change out since the stock one was for FI and now your carbureated.... the tu...
by GMAC 76
Thu Feb 08, 2018 9:21 am
Forum: Aircraft Power Only
Topic: plugs and wires
Replies: 3
Views: 663

Re: plugs and wires

I like the new autolite #386(wont rust) and the ngk ab 6 for plugs gapped at .022-.024.....make your wires metal core 7mm using copper or aluminum terminals in the mag caps...I like the copper cause you can solder them....I build wires with low profile caps if I can help ya out or napa sells the 7mm...
by GMAC 76
Tue Feb 06, 2018 8:45 pm
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

well if the carb is set up right ya sure picked a good one for your 520...4404 is top of the line everybodies looking for 'em.
by GMAC 76
Sun Feb 04, 2018 9:57 am
Forum: Aircraft Power Only
Topic: Shutdown proceedure for IO520
Replies: 31
Views: 4594

Re: Shutdown proceedure for IO520

starting with both and shutting down with mags heightens the chance of engine kickback and bad things can happen when it kicks back...it doesn't really shorten the life of the mag it just kills it outright...shutting down with the rich and lean lever or the idle shut off lever (5AA CARB) is the safe...
by GMAC 76
Sat Feb 03, 2018 8:51 pm
Forum: Aircraft Power Only
Topic: no start when cold
Replies: 15
Views: 1133

Re: no start when cold

be careful starting on both mags especially if only one is impulse....the straight mag will fire at 25 BEFORE top center and the impulse will fire close to or AFTER tdc depending on the lag on the impulse cam and that my friend is a recipe for a major kick back with one mag firing 25 or more degrees...
by GMAC 76
Fri Feb 02, 2018 11:16 am
Forum: Aircraft Power Only
Topic: Need help fuel injected 0-470
Replies: 2
Views: 348

Re: Need help fuel injected 0-470

get ahold of joey byer on SA OR SA FACEBOOK....he has all that info and knowledge
by GMAC 76
Fri Feb 02, 2018 10:22 am
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

im sure someone has maybe joey beyer or someone that works in a fuel systems shop......my only testing was in the real world of airboats ..you know same engine same prop same boat and then put a 470 carb on it and a 540 carb and compare how the engine preforms as far as idle, acceleration, wot rpm a...
by GMAC 76
Thu Feb 01, 2018 9:23 pm
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

Don't know exactly what spec sheet your referring to......there is no carb oem for a 520 they were all fuel injected....the 470 carb is too small to properly run a 520 ci engine but the Lycoming 540 carbs are the right choice .... ...if ya have a 10- part number for the carbs you need info on I have...
by GMAC 76
Tue Jan 30, 2018 4:36 pm
Forum: Aircraft Power Only
Topic: Shutdown proceedure for IO520
Replies: 31
Views: 4594

Re: Shutdown proceedure for IO520

never thought of myself as a forrest gump kinda guy but my wife said "man he nailed that one" .........those little jobs on an airboat will never end larry...lol
by GMAC 76
Sun Jan 28, 2018 10:38 am
Forum: Aircraft Power Only
Topic: Shutdown proceedure for IO520
Replies: 31
Views: 4594

Re: Shutdown proceedure for IO520

I honestly and truly love all the guys that start their engines on both mags and use only the mags to shut'em down....it keeps my little mag repair shop busy...lol
by GMAC 76
Fri Jan 26, 2018 11:14 am
Forum: Aircraft Power Only
Topic: no start when cold
Replies: 15
Views: 1133

Re: no start when cold

if and this is a big if the accelerator cavity has been corroded and the walls are now pitted and scored it will eat up a pump leather in no time...sometimes alight honing with some emery cloth will help a lot and make sure the check valve and the passage to the top of the circuit is free and workin...
by GMAC 76
Fri Jan 26, 2018 11:03 am
Forum: Aircraft Power Only
Topic: O-435-1 Mag Timing
Replies: 2
Views: 407

Re: O-435-1 Mag Timing

use the single marked tooth for engine timing.....the double marked teeth are for internal timing...so basically you have turned your 435 into a 480.....I would say that an increase in timing is in order ....maybe like the fella mention above to 20 btdc be worth a try
by GMAC 76
Thu Jan 18, 2018 11:08 am
Forum: Prop Talk
Topic: 72x36 wide blade 0520 carb
Replies: 6
Views: 963

Re: 72x36 wide blade 0520 carb

A 72X36 WIDE blade is a lot of prop..size and especially weight wise for the aircraft engine especially on the spool up imo
by GMAC 76
Thu Jan 18, 2018 9:29 am
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

might have to adjust the idle mixture screw to get a nice smooth idle and the idle rpm screw for your desired rpm but if its a true 4404 and the jet and economizer are right then pull the trigger!!!!!!
by GMAC 76
Wed Jan 17, 2018 10:00 pm
Forum: Aircraft Power Only
Topic: Sticky valves
Replies: 21
Views: 1984

Re: Sticky valves

is there any chance the impulse spring on that Siamese mag has broken
by GMAC 76
Wed Jan 17, 2018 4:58 pm
Forum: Aircraft Power Only
Topic: Sticky valves
Replies: 21
Views: 1984

Re: Sticky valves

I agree with swamphunter45....a good dose of seafoam in the gas will sure help....it is a great old school upper cyl lubricant
by GMAC 76
Wed Jan 17, 2018 12:08 pm
Forum: Aircraft Power Only
Topic: 0470-13 help
Replies: 11
Views: 1629

Re: 0470-13 help

dimotta wrote:What you have in mind

message sent
by GMAC 76
Tue Jan 16, 2018 7:17 pm
Forum: Aircraft Power Only
Topic: 0470-13 help
Replies: 11
Views: 1629

Re: 0470-13 help

deno is absouletly correct...the 6AA HELICOPTER IS A 277 bore for the 540 engines...you need an MA-4-5 with the 187 bore or a 5AA helicopter carb for your 470...I have afresh rebuilt bench tested 5AA converted to a 4-5 for the 470 if ya wanna do some dealing for the 6AA
by GMAC 76
Thu Jan 11, 2018 8:47 pm
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

there ya go!!!!......gary barber on SA facebook has some 540 carbs that are take offs...might give him a try...they are getting harder to find...good luck
by GMAC 76
Wed Jan 10, 2018 10:26 am
Forum: Aircraft Power Only
Topic: need help 0520 carb set up
Replies: 21
Views: 1713

Re: need help 0520 carb set up

the 4893 is a 470 carb with the 187 throttle bore while it will run the 520 it is not the right carb for that engine...the 520's were all fuel injected and when changed over to carburation the best carb for them is a 540 carb or a 6AA helicopter carb with the larger 277 throttle bore....im sure you ...
by GMAC 76
Thu Jan 04, 2018 10:04 am
Forum: Airboat Tech
Topic: 0290D Lycoming Coversion from Generator to Alternator
Replies: 6
Views: 749

Re: 0290D Lycoming Coversion from Generator to Alternator

classic's mount is about $100 I think
by GMAC 76
Wed Dec 27, 2017 8:03 pm
Forum: Airboat Tech
Topic: 0290D Lycoming Coversion from Generator to Alternator
Replies: 6
Views: 749

Re: 0290D Lycoming Coversion from Generator to Alternator

classic airboats in cocoa makes a nice motor mount/alternator bracket for the 4 cyl lyc using the delco one wire alt
by GMAC 76
Fri Nov 24, 2017 8:20 pm
Forum: Aircraft Power Only
Topic: Carburetor help
Replies: 3
Views: 600

Re: Carburetor help

It is borderline high psi.....3-5 would be best....but if the float/needle/seat assy are in good condition it may work.....I bench test all my carbs at 7psi at the inlet to insure that assy is working right then recommend a 3-5 psi fuel pump
by GMAC 76
Wed Nov 22, 2017 11:47 am
Forum: Airboat Talk
Topic: Breather tube
Replies: 14
Views: 1881

Re: Breather tube

just remember one thing mr wells....if ya run that breather tube over the top of the cage ALL THE MOISTURE that gathers in it will eventually run right back into the engine and contaminate the oil...better to run the hose down so that moisture cant get into the engine...I have seen that little bit o...
by GMAC 76
Sun Oct 22, 2017 7:54 pm
Forum: Airboat Tech
Topic: replacing fuel pump on o520 aircraft
Replies: 3
Views: 773

Re: replacing fuel pump on o520 aircraft

X2 ON THE FACET ELECTRIC FUEL PUMP!!!!

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