Restoring 1986 Sea Nymph SS155 (pics)

lmuss53

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Piece, the fuel charge on 2 strokes is the lube and to a certain extent a coolant for the engine. When you get a cylinder that is not getting fuel it loses the lube and cooling benefits the charge provides. This can lead to the cylinder wall drying out and scoring or the piston not cooling from momentary contact with the fuel and melting. The pee stream would not necessarily get hot or even warm while these very bad things were happening. That's why it is important to make sure you have good fuel flow to both carbs before you run the motor much.

For all we know it is running fine and I just can't hear right anymore. Do the plug wire test and hopefully it bogs down evenly with each wire off. If that's the case go for the trial run.

If you find out that one carb isn't letting fuel flow properly, please take the time to pull them both off and clean them. They come off linkage and all I'm pretty sure, and the disassembly, cleaning and reassembly are pretty simple and straightforward.

If you have to pull them get yourself a clean, dry, well lighted 3'x3' surface and just lay the parts out as you take them off, and then put it all back together in reverse order. Make sure you blow out all the little orifices in the carbs and that the floats are back together with the valves in the right location. Do a youtube search, I think there is an OMC carb rebuild video there. The ones in the video are larger than yours but it is basically the same task.

A rebuild is better, but a good cleaning usually will fix most issues. I don't pop out the little aluminum caps to look under them, but clean every other orifice. Canned air for computers will work if you don't have compressor air.

Piece, no primer solenoids at my friends shop, he says they fly out the door as soon as he gets them. I hope the wire or bigger screw trick works.

There are a few on ebay, $60 to $80 buy it nows.
 
Last edited:

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Piece, the fuel charge on 2 strokes is the lube and to a certain extent a coolant for the engine. When you get a cylinder that is not getting fuel it loses the lube and cooling benefits the charge provides. This can lead to the cylinder wall drying out and scoring or the piston not cooling from momentary contact with the fuel and melting. The pee stream would not necessarily get hot or even warm while these very bad things were happening. That's why it is important to make sure you have good fuel flow to both carbs before you run the motor much.

For all we know it is running fine and I just can't hear right anymore. Do the plug wire test and hopefully it bogs down evenly with each wire off. If that's the case go for the trial run.

If you find out that one carb isn't letting fuel flow properly, please take the time to pull them both off and clean them. They come off linkage and all I'm pretty sure, and the disassembly, cleaning and reassembly are pretty simple and straightforward.

If you have to pull them get yourself a clean, dry, well lighted 3'x3' surface and just lay the parts out as you take them off, and then put it all back together in reverse order. Make sure you blow out all the little orifices in the carbs and that the floats are back together with the valves in the right location. Do a youtube search, I think there is an OMC carb rebuild video there. The ones in the video are larger than yours but it is basically the same task.

A rebuild is better, but a good cleaning usually will fix most issues. I don't pop out the little aluminum caps to look under them, but clean every other orifice. Canned air for computers will work if you don't have compressor air.

Piece, no primer solenoids at my friends shop, he says they fly out the door as soon as he gets them. I hope the wire or bigger screw trick works.

There are a few on ebay, $60 to $80 buy it nows.


Thanks for all the help Imuss! I had to move a buddy out his house this past weekend and get my boat out his garage :rolleyes: so no work was done. We finished up last night... took the day from work to help him finish moving! A smashed foot and sliced hand later but its over! Hopefully by Thursday I'll have tested the motor by pulling the plugs and fixed the primer solenoid with the wire or larger screw... Keeping our fingers crossed for a Saturday splash... had to keep that hush hush don't want the dry dock gods throwing another wrench in the system :D

Oh and on a side note. Just got on the site with my iphone... im diggin the new mobile site... SOOO much better than navigating the full site on a phone! Props Iboats!
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Well just performed the spark plug test on the motor. First we tried the wire strands in the screws of the primer solenoid. Tighten the screw down well. Then pumped the bulb no leak. Went to start it and when I pushed in the key BOOM leaked again... Sooo looking like that needs to be replaced. 😔 Next the motor fired right up. Got it to idle and pulled the top plug boot. Motor died... Thoughts maybe it wasn't warm enough yet. Restarted and fired right up... Pulled the bottom plug and nothing happened. Replaced and pulled top plug... Dead motor. Sooo imuss has the ear of the day... Motor is confirmed only firing on one cylinder. Whelp time for boat to go to shop to figure out why. I'm think a jet is clogged cuz when I plugged the bottom plug I could hear the cap sparking. ANOTHER set back for the old nymph! Hopefully I don't need a new motor 😔
 

lmuss53

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Re: Restoring 1986 Sea Nymph SS155 (pics)

I'm sorry to have brought you that news, but knowing now might have saved you big trouble later. If you want to go one more step try the squirt can with a little premix in the bottom carb. If she surges that will just about confirm she needs a carb cleaning. Try to find a trustworthy mechanic, somone who won't sell you new a stator, 2 coils and a ignition module to fix a dirty carb. Sadly there are many boat mechanics around like that. The guy where you got the fuel pump seemed to be pretty decent, maybe try there. If you do the test and confirm it is fuel related you will have at least that bit of information to take with you to the mechanic. Watch that youtube vid on the omc carb rebuild, it really isn't very hard to do. ;) If you've got an Uncle who is good with lawnmowers he can do it for you.

OCCASIONALLY a couple of gentle taps on the side of the carb will dislodge whatever is stuck or free up a stuck float. You might want to try that too. Very gentle taps with a screwdriver handle on and around the bowl.

I'd be real surprised if you need a new motor, I would bet money on the dirty carb. They are almost always dirty when they sit for a while.

Hang in there bro, you'll be styling for the 4th of July.
 

ezmobee

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Sorry to hear about the setback but I agree with lmuss that it's unlikely to be a serious problem. It sucks to have to pony up for a professional but the couple times I've done it it's been well worth it and I got years of trouble free service afterwards.
 

Piece715

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Messages
757
Re: Restoring 1986 Sea Nymph SS155 (pics)

I'm sorry to have brought you that news, but knowing now might have saved you big trouble later. If you want to go one more step try the squirt can with a little premix in the bottom carb. If she surges that will just about confirm she needs a carb cleaning. Try to find a trustworthy mechanic, somone who won't sell you new a stator, 2 coils and a ignition module to fix a dirty carb. Sadly there are many boat mechanics around like that. The guy where you got the fuel pump seemed to be pretty decent, maybe try there. If you do the test and confirm it is fuel related you will have at least that bit of information to take with you to the mechanic. Watch that youtube vid on the omc carb rebuild, it really isn't very hard to do. ;) If you've got an Uncle who is good with lawnmowers he can do it for you.

OCCASIONALLY a couple of gentle taps on the side of the carb will dislodge whatever is stuck or free up a stuck float. You might want to try that too. Very gentle taps with a screwdriver handle on and around the bowl.

I'd be real surprised if you need a new motor, I would bet money on the dirty carb. They are almost always dirty when they sit for a while.

Hang in there bro, you'll be styling for the 4th of July.

Thanks Imuss! and absolutely no need to apologize... you saved me a motor with that well trained ear of urs! So for that I humbly thank u kind sir :p I'm pretty certain that its the carbs... Well lets just say it better be :mad: I started a thread on here a while back looking for a good mechanic in Little Rock metro. It was back when i was remounting the motor and CMC... EZ caught me and scolded me for trying to pawn off easy work :rolleyes:. Incoop gave me the names of a couple of places to try. So I'll be making phone calls today.

Sorry to hear about the setback but I agree with lmuss that it's unlikely to be a serious problem. It sucks to have to pony up for a professional but the couple times I've done it it's been well worth it and I got years of trouble free service afterwards.

Let's keep our fingers crossed EZ. The last place I took my boat to definitely ripped me off; which was proven when I tore into the lower unit. Like I told imuss... Incoop gave me his recommendations on mechanics. I could try to tackle the carbs myself but I think its time a pro stepped in... Depending on the length of wait at the shops... its looking like July 4th for big splash date now... :rolleyes:
 

jasoutside

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Such a bummer your float keeps getting bumped back man:(

You'll get er!:D
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Such a bummer your float keeps getting bumped back man:(

You'll get er!:D

It's all good... it will just make the water all that much smoother for when she is up and running. On the plus side I never thought I'd learn anything about outboard repair but so far i have removed and replace a VRO pump with a fuel pump, dropped the lower unit multiple times, cleaned and changed the impeller, replaced fuel lines, tested an operating motor for cylinder firing, adjusted throttle cables, replaced exhaust gaskets, worked on a primer solenoid, designed and installed 12v wiring system with switchable dual battery setup, and repair some weird hot horn wiring in the powerhead (reason for wiring still a mystery have to test hot horn to see if I can determine the reason). So knowledge is my prize... And Illl Take IT!
 

ezmobee

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Re: Restoring 1986 Sea Nymph SS155 (pics)

You've already done to more to your motor than I've done to mine. Perhaps fiddling with the carbs is not beyond your capability? Unfortunately the last time out I had a mysterious super quick power loss thing happening with mine and I haven't had a chance to get it out again to try things to see if I've really got a problem or not.
 

64osby

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Hey Piece, agree that it's most likely a carb issue, but just wondering if you have checked compression on the motor?
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

You've already done to more to your motor than I've done to mine. Perhaps fiddling with the carbs is not beyond your capability? Unfortunately the last time out I had a mysterious super quick power loss thing happening with mine and I haven't had a chance to get it out again to try things to see if I've really got a problem or not.

I have mulled that question over in my mind over and over. It's just im too OCD and would be afraid to screw something up. Ill do some reading tonight. If i feel i can manage ill try it out. If not to the shop it goes in the am tomorrow

Hey Piece, agree that it's most likely a carb issue, but just wondering if you have checked compression on the motor?

Well when i had the motor overhauled when i first started the restore that was my main concern. They were to check the compression and perform maintenance on carbs, lower unit fluids, plugs, water pump, etc. Bill was about $400 worth of work. They said it checked out fine and ran strong. BUUUUTTTT when servicing the lower unit just a couple weeks ago i found out that they never even touched the water pump but i got charged. Sooo what work they did... who knows? This something that i can do easily? Guessing it needs a special tool.... See posts 495 and 496 for what i found with the water pump and how i figured i got swindled. Sad day when the average person can't trust a professional to perform easy routine maintenance
 

ezmobee

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Re: Restoring 1986 Sea Nymph SS155 (pics)

From what I understand, compression testers are only a couple bucks at any auto parts store and they also have them available as loaners.
 

Todd4

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Well, sorry to hear about your setback, but it's a good thing you checked. I burnt a hole through a 2 cycle motorcycle piston once when I tried to drive it on the freeway. It had a leaking case gasket and sucked air into the fuel mix, causing it to run lean. It probably would have run like that forever, if I hadn't tried to open her up and run her hard. Anyway, point being that you most probably didn't hurt your motor yet, but you might have cratered a piston if you took it out on the water and tried to run it that way. It sounds like it could be just a stuck float (the screwdriver trick may work). As I posted erarlier about a stuck float, either you get no gas or the gas overflows the bowl and runs out of the vent hole - looks like you might be getting no gas (or a jet could still be clogged) - either way not that hard to fix, by you, or a reputable boat mechanic. You'll be on the water in no time. :)
Todd
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Well boat went into shop today. More updates as I get them.
 

sprintst

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Hey dude. That's a new boat now don't ya know. Quite the transformation from the original. Got to be crazy to be that thorough but it takes one to know one :) She's a beautiful boat that's all yours now.

With any luck it will be something minor and you'll get out on the water to show off all your hard work. Many many hours of good times to come.

PS.. Does feel like a another full time job at times though doesn't it :) In the end you will know every nut and bolt and will enjoy the boat more in the end because of it.
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Hey dude. That's a new boat now don't ya know. Quite the transformation from the original. Got to be crazy to be that thorough but it takes one to know one :) She's a beautiful boat that's all yours now.

With any luck it will be something minor and you'll get out on the water to show off all your hard work. Many many hours of good times to come.

PS.. Does feel like a another full time job at times though doesn't it :) In the end you will know every nut and bolt and will enjoy the boat more in the end because of it.

Appreciate it Sprint! Growing up my mother was a perfectionist... white glove style cleaning checks, clean and tidy house 24/7, etc. I guess some of that stuck with me... I definitely have my OCD tendencies :rolleyes: but you're right.... takes one to know one :D. Mighty fine job on ur rig as well! The color choice and the interior are just amazing. Looking forward to seeing how the doghouse finishes the stern.

I could use a bit of luck with the motor. Still waiting to hear what they found... shop was at a 1.5-2 week wait when I dropped it off. Gonna swing through today just to see if she has moved any. I will say I have learned a lot; more than I thought possible about boats in general. Now when we go to the lake and someone's boat acts up its always "Hey Mark... Fix this!" :facepalm:. And I am by no means needing to be thrown into that position :eek:

There is an Arkansas meet and greet trying to be put together by incoop. Hoping I get to meet some of the iboat family in the months to come. This project would probably be sitting next to my house with pressure treated ply and glued carpet if I hadn't stumbled upon this site. Hats off to the whole lot. And thank you again for you kind words Sprint! Smooth waters!
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Soooo I haven't heard from the boat shop yet and I don't expect anything major to be wrong, but it always can be fun to speculate and shop for new power ;) What would your suggestions be for a new power plant.... 80 hp max for the boat.... Suggestions of years and brands to stay away from; I know electric shifts need to be tossed, what years were those? Throw some suggestions out there as i eventually want to upgrade

Found this and its a good price but again no nothing about what years to steer clear of... this would probably be a piece together but sounds promising

http://littlerock.craigslist.org/boa/3077549602.html
 

ezmobee

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Electric shift OMCs were pre-1973. The 1973-1978 motors are fine and have pretty good parts support. From what I understand there were some changes made in '78 that were carried through for a LONG time so those motors are ideal. I think my 1981 was the first year that they used the primer circuit as opposed to a choke and let me tell you, it makes a HUGE difference in cold starts. For your boat, I don't think I'd go with a V4. It would be a little stern heavy with probably not much power gain. The triples have great power to weight ratios. An OMC 70-75 would be just dandy on your boat. (Although the greatest motor would be one of those newer Yamaha 3 cyl 90's but that'd prolly be pretty expensive).

I don't know jack about Mercs.
 

Piece715

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Re: Restoring 1986 Sea Nymph SS155 (pics)

(Although the greatest motor would be one of those newer Yamaha 3 cyl 90's but that'd prolly be pretty expensive).

Thanks for all the info EZ! Much appreciated. Always was curious to the years. Will keep this in mind as i surf the channels wanting ;) Oh and I FEEL ya on the newer yammys! When i started the project that was the motor i wanted to find! Patience is the key.. it will happen!

I don't know jack about Mercs.

This is how I feel about most topics :facepalm:
 

lmuss53

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Re: Restoring 1986 Sea Nymph SS155 (pics)

Everything EZ said is excellent advice, V4 is too much for your boat, an OMC non electric shift triple is great for your hull (that's what's on mine). They last and last, are readily availabe and cheap. Don't rule out a later model Merc/Mariner 75 triple, I had 75 and a 90 hp (same block) 1998 and 1996 models and they were great motors. On a brand new motor for your hull I would look at a direct inject 2 stroke, 75 Optimax would be sweet. Google T and M Marine, they have very good deals on Merc motors, great deals on brand new scratch and dent factory seconds. Yammies are great too. I would stay away from the 4 strokes for the same reason as the v4, too much weight.
 
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