18 hp Fastwin Bogging Down

jonbellamy

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Hey guys, new to iboats.com I've done a bunch of searches about this topic, but haven't been able to find anything that will help me. I was just given a late 60's or early 70's Evinrude Fastwin 18hp by my grandfather. The motor hasn't run in probably 5-10 years (but it started right up) and was leaking oil from the lower unit. My grandpa took it to the shop and had the carb rebuilt, lower unit seals replaced,and a bunch of other things. I took it out for a test run and at first it idled good and reversed fine, but i noticed the lever that keeps the roller from going in neutral was hanging when i put it into gear, preventing me from going full throttle. Eventually it stopped doing that and the roller was free to go full in forward--but here's the problem: When i throttled up, the engine would act as if it was about to go, but then it would bog down and do about 4-5 mph. The engine sounded like it wasn't even going 1/4 of the rpms it should. I'm thinking it's not running on both cylinders. My grandpa is going back to the shop tomorrow, but i was wondering if you guys could give me some possibilities so that if the guy at the shop doesn't fix it this time i don't have to spend more money on him. I'm not good with boat engines and so if y'all could speak to me in basics that would be awesome.
 

HighTrim

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Re: 18 hp Fastwin Bogging Down

Sounds like it may still have the original coils. If the are original, and cracked, the are junk.
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

Sounds like it may still have the original coils. If the are original, and cracked, the are junk.

Sorry, but like i mentioned, I don't know too much about boat motors. For the Fastwin, the coils are under the flywheel correct? Will i need any special tools or anything to check the coils?
 

HighTrim

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Re: 18 hp Fastwin Bogging Down

Pull of the recoil (manual starter), then in the flywheel there will be an inspection window held on by 3 screws. Remove the screws, pop off the cover then have a look inside while turning the flywheel clockwise. If the coils are all cracked, they are not good.
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

My grandfather took the boat back to the shop today. The guy said there was nothing wrong with the motor and that the boat shouldn't even be planing. I call bs because i know this motor goes faster than 4mph and i've seen others with the same style boat and motor going 20mph. I have another question for you guys. Will a bad coil still make a spark in the spark plug? Would a simple spark tester be sufficient for checking a bad coil or would i still need to remove the flywheel etc?
 

nwcove

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Re: 18 hp Fastwin Bogging Down

if all is well with your fastwin, it should push a barge at 4mph! and yes a bad coil can still make a spark, but you need a good spark/proper air fuel ratio and good compression to ignite fuel. i would start with a compression test ( or call the shop and ask what the compression is). if they cant answer that question, try a new shop. your motor is quite easy to trouble shoot, as hightrim stated, pull the recoil, then the small cover over the inspection hole, have a look at the coils, maybe try to take a pic and post.
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

if all is well with your fastwin, it should push a barge at 4mph! and yes a bad coil can still make a spark, but you need a good spark/proper air fuel ratio and good compression to ignite fuel. i would start with a compression test ( or call the shop and ask what the compression is). if they cant answer that question, try a new shop. your motor is quite easy to trouble shoot, as hightrim stated, pull the recoil, then the small cover over the inspection hole, have a look at the coils, maybe try to take a pic and post.

Thanks for helping me out so far. I'm going to try to get some pictures this week or weekend as well as a video of what the motor is doing.
 

kfa4303

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Re: 18 hp Fastwin Bogging Down

My grandfather took the boat back to the shop today. The guy said there was nothing wrong with the motor and that the boat shouldn't even be planing. I call bs because i know this motor goes faster than 4mph and i've seen others with the same style boat and motor going 20mph. I have another question for you guys. Will a bad coil still make a spark in the spark plug? Would a simple spark tester be sufficient for checking a bad coil or would i still need to remove the flywheel etc?


Hi jon. Never go back to that shop again. He clearly doesn't know what he's talking about. My '66 20hp Johnson pushed me along in my 14' semi-v hull aluminum boat at a little over 20 mph and hops up on plane in under 5 seconds. A bad coil will prevent a proper spark and may well be the source of your problem. All OMC coils of this era failed and need to be replaced. The new ones will last forever and only cost about $20 each right here at iboats. Here's a great link that can walk you through an entire ignition rebuild.

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

Here are some vids of me in my boat moving along at a decent clip.

http://www.youtube.com/watch?v=LEGgm8B8mic

1966 Johnson FD-20C, 20hp outboard on a 1959 Arkansas Traveler DUT-14 aluminum runabout - YouTube
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

Hi jon. Never go back to that shop again. He clearly doesn't know what he's talking about. My '66 20hp Johnson pushed me along in my 14' semi-v hull aluminum boat at a little over 20 mph and hops up on plane in under 5 seconds. A bad coil will prevent a proper spark and may well be the source of your problem. All OMC coils of this era failed and need to be replaced. The new ones will last forever and only cost about $20 each right here at iboats. Here's a great link that can walk you through an entire ignition rebuild.

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

Here are some vids of me in my boat moving along at a decent clip.

Wakulla Beach, FL movie.wmv - YouTube

1966 Johnson FD-20C, 20hp outboard on a 1959 Arkansas Traveler DUT-14 aluminum runabout - YouTube

Thanks for the reply. I called the guy today and he told me the motor was running on both cylinders when it left his shop. I then asked him if he checked the compression, sparks, and coils. No. No. No. I will not be going back there and will ask my grandfather to do the same. When I get a chance later this week i'm going to check the coils and post pics/video. I'm sorry for so many questions but I'm excited to get this boat and motor for FREE and would love for it to run properly, but...Are both coils in the first link in this thread the same part? IE if both coils are bad, should i order two of the same of these Ignition Coil for Johnson/Evinrude 582995 584477, Mercury/Mariner 802371A1, GLM 72100 - Sierra - iboats

Also, if i have to take the flywheel off, is there a link to the correct amount of torque needed to put the flywheel back on? I believe this is '68 18hp Fastwin.

Edit: I see you're running in Wakulla. Do you live around there, because I live in Tallahassee and would definitely love some help!
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

So it's come to my attention that my problem could be that the motor is too far below the hull. I read that the cavitation (or anti-ventilation) plate should be even with the bottom of the transom and mine is about 4 inches below. Here is a picture. What do yall think? boat.jpg
 

nwcove

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Re: 18 hp Fastwin Bogging Down

the motor is quite low and tilted in a bit much for my liking, but if the motor was working properly it should still get that boat up on plane.
 

HighTrim

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Re: 18 hp Fastwin Bogging Down

Yes you will likely need 2 coils, if they are shot.

Fastwin flywheel torque is 40 ft/lbs.
 

kfa4303

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Re: 18 hp Fastwin Bogging Down

Hello again jon. Yes, both coils should be replaced at the same time, they're about $20 each, but will last forever. I would get a "tune-up kit" as well. It contains a pair of points and condensers and run about $20 as well. You should get some new Champion J4C or J6C spark plugs too. Generally speaking, you want the anti-vent plate, found just above the prop, to be level or slightly higher than the keel of the boat. OMC motors of this era sort of have an odd leg length of 18'', whereas most transoms of the day were 15'', so they tend to hand a bit low. I built a little transom riser to make up the difference. I would concentrate on getting her up and running, then you can tweak the motor height for optimum performance. Here's a great ignition rebuild link.

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

Hey guys. I was able to get a couple of videos today. The motor was jumping around a bunch today. There was a point that it actually got up on plain and ran about 20mph. The motor would be full throttle and not going anyway and then all of a sudden kick in like it was gonna run full rpms, then stop and go slow, etc.

In this video it actually gets top rpm i think. Note i'm holding the throttle wide open the whole time and at the end i try to give it gas but it doesn't go anywhere:

The next post has the next video...
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

This video shows what it has been doing the majority of the time. It jumps up and down and you can hear it sound like it wants to get going, but doesn't. I have it fuel throttle the whole time too:
 

Grub54891

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Jun 17, 2012
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Re: 18 hp Fastwin Bogging Down

Shure sounds like only 1cyl is firing on that last video.check them coils/points as stated before,run the compression test before ordering any parts!
Grub
 

HighTrim

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Re: 18 hp Fastwin Bogging Down

Jon we given you the steps that need to be taken here to pinpoint this. We will need your help now.
 

jonbellamy

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Re: 18 hp Fastwin Bogging Down

Jon we given you the steps that need to be taken here to pinpoint this. We will need your help now.

You're right, just updating in case someone else is having similar issues. I'll eventually get the flywheel off, but i don't have the tools and money for parts. I'm hoping next weekend or the weekend after I can get some work done.
 
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