Help!!!!

jonboatboy

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Joined
Aug 14, 2011
Messages
5
I have a 72 18HP. Evinrude that i got from a guy that has been sitting in a central heat and air garage for about 5 years. He told me to take it and try it and if I liked it I could purchase it from him for just 400 bucks and any money I had to spend on it he would knock it off the price. When I first got it home it wouldn't start so the next day I took it to a repair shop to have it checked out. Compression was 100 on both cylinders, fire was good. I took it home and pulled the carb off it and cleaned it with carb and choke cleaner and compressed air. Put it back together and it would start and idle but wont pick up speed. I changed the spark plugs and replaced with what was in it (Champions) and I gapped them to .30. Now it idles great and starts great too, but it takes a while for it to pick up speed (bogs) and bout the time I get it up on plain it bogs down again. I don't know what else to do and the repair shops around here act like they don't want to work on it(its a pull start) and I am all out of ideas.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Help!!!!

When you cleaned the carb did you remove and check the high speed orifice, was it plugged or restricted? Did you check the fuel pump operation, is the filter screen on the fuel pump clean?
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: Help!!!!

Pump the bulb when it bogs...if the motor picks up you have a fuel delivery issue.
 

jonboatboy

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Joined
Aug 14, 2011
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5
Re: Help!!!!

I've tried pumping the bulb while its running wide open and it just bogs worse. I dont know what the high speed orifice is or where its located. I just checked where I thought fuel and air may travel. Im a car guy and I work on cars for a living so Im trying to use my knowledge of that towards this motor, but if all and any input, comments , advice, criticism, and information is greatly appreciated!
 

jonboatboy

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Joined
Aug 14, 2011
Messages
5
Re: Help!!!!

Also another thing I forgot to mention is the plugs were gettin drowned in gas, and it ran really bad but carb. cleaner and compressed air cleaned them right up.
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: Help!!!!

marineengine.com will have diagrams of your motor's components..under carbs look for the orfice plug < jet >, be careful removing it if you decide to as it's easy to distort or snap the "ears" of the jet < being a car guy/ tool guy..look for brp jet removal tool 317002 ~ $20..pricey. but it's built for the job >...you can clean it reasonably well in place with a copper wire of a smaller diameter than the jet < don't distort the jet size>...as simple as the carbs are, they must be absolutely clean to function well...then go to the search feature in the upper right corner and look for link%sync for about any 2 cylinder omc..principal is the same....the carb linkage roller will be on a mark on the timing cam at idle...as the throttle plate just begins to open...then when the roller is on the highest point of the timing cam, the throttle plate should be perfectly horizontal in the carb throat at wot
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: Help!!!!

If it starts great and idles great, but bogs at high speed, you may have a coil cutting out when it warms up. Motor will run fine at idle on one cylinder, so check spark once she's warmed up.
 

jonboatboy

Recruit
Joined
Aug 14, 2011
Messages
5
Re: Help!!!!

Ok I do remember the high speed orifice was really clogged up and dirty when I cleaned it. I took the boat over to the guys house I got it from and we pulled it off the first time and scraped the gunk out of it. He put a small drill bit on a drill and ran it through the drain up into the high speed orifice. There was a few metal shavings that came out. Now that you talk about that orifice plug I pulled it out and it was a little gummy in the threads but didn't look like anything that would cause it to mess up in there. I wonder if maybe he screwed the orifice plug up because with the plugs getting drowned in fuel it would make since if it were to be the problem. It didn't look like it had been killed but if its something that the eye couldn't see I would never know. Lindy46 I am gonna try your idea too tomorrow when I go to work Ima grab our spark tester and see if it miss fires when warm. Man I really appreciate yalls help and input. This website is a big help. I always google any problem I get stuck on about cars and I always find the answer so Im hopeing to do the same on this boat motor. Do yall think its worth messing with or should I give up and take my losses now while i'm still in it cheap?
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Help!!!!

If the high speed orifice was drilled over size, it could cause you problem. Are you sure you cleaned all the passages in the carb really well and blew out all the passages with compressed air?
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: Help!!!!

from having read many posts on this forum concerning the 18hp..it's one of the most reliable, bulletproof engines around...a huge number were produced and parts are plentiful..for a motor almost 40 years old these are great benefits
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Help!!!!

Yea, there's a good possibility that you need a new carb now that a drill has made shavings.
 

jonboatboy

Recruit
Joined
Aug 14, 2011
Messages
5
Re: Help!!!!

He was drilling the through the drain part of the carb. and up into and past the orifice plug. Like I said the orifice plug didn't look like it was tore all to pieces. I'm starting to get really frustrated with this thing. I had it out today and it does the same thing over and over. Slow getting up to speed like its missing or something and then when it does pick up the thing will flat out get it for about 3 seconds then fall down on its face and bog then pick back up. I hope there's still parts available for this thing. I still haven't gave dude a dollar for this motor and hes got my cell phone number and I've not got a phone call. I called him bout 2 days ago and left a message so he don't think I'm trying to screw him but I don't want to put him off so I'm trying to get this thing running. I got it a little 12 ft jon boat and it gets up and flies when it wants. Takes no time to get to my fishing spots compared to that ole 5hp Briggs and Stratton. Them things are junk!
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Help!!!!

Just my 2 cents worth, if you have good spark, it will jump a 1/4" air gap and is bright blue. And if the compression is good, you said it 100 psi, should be good enough. The only thing left is fuel delivery. The size of the high speed orifice is calibrated to the engine size, if it is oversized it will cause problems. You should be able to replace the orifice as long as no other damage was done to the carb bowl.
One other thing you might want to check is the flywheel key and make sure it is not sheared and throwing it out of time a little.
 

cajuncook1

Chief Petty Officer
Joined
Sep 3, 2009
Messages
559
Re: Help!!!!

The guy who "helped" you out probably did not do you any favors. I'm sorry, but short cuts when it come to good maintenance will bite you in the bum every time.

The best way to clean a carburetor is to disassemble it and soak it for a couple of hours in carburetor dip(no plastic or rubber pieces...will dissolve). Rinse and blow out all the orifices with carb spray and then blow out with compressed air.

Get a new carburetor kit. New packing and gasket and all.

It takes longer but it is done right!! Get a manual and learn to do it the right way.



Here is a diagram of your carburetor. If the high speed jet is damaged replace it. It cost about $8 at www.marineengine.com

Here is the link to your carburetor diagram.

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1972&hp=18&model=18202R

http://www.marineengine.com/parts/evinrude-johnson-parts-diagrams/EVINRUDE/53061.gif

I hope you are able to sort out your carburetor problem. Those 18hp/20hp/25hp motors from the late 1950's to mid 1970's are well built engines.
 
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