Muffs and decarb?

NgtvNrg

Seaman Apprentice
Joined
Apr 30, 2007
Messages
49
I have a 1996 model evinrude e90tleda on a 1997 Hydra-Sports 17 Skiff; I purchased the boat in March and have really only began to use it. On the 6th trip out the overheat alarm sounded twice, both times at or close to wot. I have since replaced the thermostats (The previous owner had apparently cut the center out of the thermostats)and poppit valves with a rebuild kit, cleaned the housing and done a compression check: 125, 135, 125, 140 I was wanting to do a decarb as described in the FAQ this weekend and wondering if I could do it on muffs or if it must be done under load. (I am prepared to deal with the mess and smoke)
Any help would be greatly appreciated.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: Muffs and decarb?

I have a 1996 model evinrude e90tleda on a 1997 Hydra-Sports 17 Skiff; I purchased the boat in March and have really only began to use it. On the 6th trip out the overheat alarm sounded twice, both times at or close to wot. I have since replaced the thermostats (The previous owner had apparently cut the center out of the thermostats)and poppit valves with a rebuild kit, cleaned the housing and done a compression check: 125, 135, 125, 140 I was wanting to do a decarb as described in the FAQ this weekend and wondering if I could do it on muffs or if it must be done under load. (I am prepared to deal with the mess and smoke)
Any help would be greatly appreciated.

Check out the frequently asked questions. You might find something in there. Personally i would NOT be doing it on muffs due to RPM limitations while on them. I think that the idea is to BLAST the crud out at the top end of your RPM range.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Muffs and decarb?

Welcome to iboats!

decarb, excellent idea. muffs are fine. Let us know if it impacts your compression numbers.

[edit: added after reading ken's response - the FAQ's do indicate that running at WOT might add effectiveness - can't confirm or deny based on my experience - but doing on the muffs is ok. Long as you know don't rev her up on the muffs, any more than a fast idle, or enough to keep her running.]
 

eli_lilly

Chief Petty Officer
Joined
Dec 22, 2005
Messages
435
Re: Muffs and decarb?

rather than buying Seafoam Deep Creep you can use regular seafoam in and put it into a spray bottle, it's the same stuff. here's a link that will help with the exhaust mess. be sure to replace the spark plugs when completed. http://forums.iboats.com/showthread.php?t=192725&highlight=muffler

What is the correct way to spray it into the intake when using Deep Creep? The service manual and some messages here say to never run the engine with the airbox off, but how do I get the spray into the intake? Should it just be sprayed into the side openings of the airbox?

-E
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Muffs and decarb?

take the air box off. they say that so people don't take them off and leave them off. all it's for i to cut down on carb noise, and keep crap out of the carb. look how many of the smaller engine don't even have one, all they have is 1/4 inch mesh screen.
 

NgtvNrg

Seaman Apprentice
Joined
Apr 30, 2007
Messages
49
Re: Muffs and decarb?

Thanks for your replies. I'm planning to do the decarb using the 3 gallon gas tank method. The FAQ suggests to do it at under 2500 RPMs. Would I still need to run at WOT?
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Muffs and decarb?

if you do it on muffs definately not over 2500, preferable not over 1500. you want the engine to get up to running temperture. so the stuff can work. over 1500 you can get a runaway you can't shut down.
 
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