Mako 171 - Jelly substance on top of the fuel tank

[spc337]

I'm looking at purchasing an '89 Mako 171. During inspection, I opened the cover under the console and found a jelly substance all over the fuel tank. It didn't smell like fuel but obviously a concern. I would have thought an '89 had ethanol compatible parts and given this wasn't in the the tank I'm wondering if the foam has failed some how.

Any one see something like this before?

https://www.flickr.com/photos/seanpcunningham/37110562884/in/dateposted-public

[Texas 17]

I posted up on your THT thread. I think its probably a nasty biology experiment from water sitting on the tank. But Id guess a tank replacement is upcoming, just because it usually is unless its been done. Figure $300 for the tank fabrication, another $1-200 for materials if you replace all the fuel lines (which you should), and a few weeks of cussing mostly to pull and replace the original fuel fill line.

Its worth rewriting the console while its off, bc its likely to need it.

[spc337]

quote:

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Originally posted by Texas 17


I posted up on your THT thread. I think its probably a nasty biology experiment from water sitting on the tank. But Id guess a tank replacement is upcoming, just because it usually is unless its been done. Figure $300 for the tank fabrication, another $1-200 for materials if you replace all the fuel lines (which you should), and a few weeks of cussing mostly to pull and replace the original fuel fill line.

Its worth rewriting the console while its off, bc its likely to need it.

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Thanks - adding my THT reply here too..

The substance is on top of the tank, not in the tank which is why I'm more concerned about problems with the foam and other areas of the hull.

There was another post on THT with a similar photo but the original poster never followed up with his findings. I suspect pulling the console and replacing the tank is needed and re-wiring at that time is certainly a good idea. I'm more concerned about what I can't see.

I opened the hatch in the stern and seemed pretty clean but the current own had replaced the steering cables so maybe it was cleaned at that time - bilge looks good too. The current owner seemed pretty knowledgeable about what is good and bad about the boat and he was equally perplexed about the jelly substance. Mind you, he didn't go out of his way to show me.

Is there a method to check the foam under the deck without drilling? I'm not sure where Mako Foamed and where they didn't so not sure how to inspect.

The owner just rebuilt the Yamaha Carbs @ $1200, new steering cable, new bottom paint, basically rebuilt the trailer and the price is ~$8k for a '89 Mako 171. The hull exterior looks in great shape. There was one crack repaired on the transom but it felt solid. He pulled the motor off to replace the cables and said he didn't see any rot or issues.

https://www.flickr.com/photos/seanpcunningham/37785589516/in/dateposted-public

Tough to really know but as far as a seller I don't know goes, he seemed honest.

[Texas 17]

Price seems high to me. You could weigh the boat to get an idea if the foam is saturated, but I dont recall any access points to break up some foam deep in the boat which is where the water would be.

Seems like thats a $4k-$6k boat unless its in tremendous shape and the power and electronics are newer, but maybe even the old ones have jumped in value the last few years.

[Texas 17]

By the way, the corrosion on the tank will be outside in. That junk being on top of the tank is not good news. It means water is sitting in the coffin and at least that foam is likely wet.

[BlueCrab]

I have that same "jelly" on mine. Looks pretty gross[xx(]

I am going to attempt to remove my T-Top and console in one piece this winter and replace tank and probably foam. Hopefully I don't need anything else while in there. That's going to cost enough.

[spc337]

quote:

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Originally posted by BlueCrab


I have that same "jelly" on mine. Looks pretty gross[xx(]

I am going to attempt to remove my T-Top and console in one piece this winter and replace tank and probably foam. Hopefully I don't need anything else while in there. That's going to cost enough.

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Given this probably means water is in the coffin - does that imply other likely damage or am I making to much of this? If the tank replacement is something straightforward for a mechanically inclined person to handle then maybe I should negotiate the price down accordingly and move forward if we can reach agreement. I'm just nervous what else this may indicate. I don't want a boat that requires me to cut the deck and get deep into fiberglass repairs/stringers etc.. No time for that unfortunately.

[Texas 17]

It doesnt necessarily indicate any other issues. Deck problems would show by soft spots. Stringer and transom issues that need urgent repair will generally show by transom flex and cracking. If it has no bottom paint you are likely in decent shape on that because the boat is less likely to be wet in the bilge constantly.

[michigan dave]

I will have a clean 171 angler for sale when I get back down to Florida this fall...Tank and hoses already done. Solid boat with the cleanest 135 Merc in the area. I brought the merc down with me last year from Michigan. Comes with bimini, full cushions, stereo, graph, and a very good trailer. Just passing it along if your not happy with the one your inspecting.

dave

[spc337]

quote:

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Originally posted by Texas 17


It doesnt necessarily indicate any other issues. Deck problems would show by soft spots. Stringer and transom issues that need urgent repair will generally show by transom flex and cracking. If it has no bottom paint you are likely in decent shape on that because the boat is less likely to be wet in the bilge constantly.

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It does have bottom paint. The bilge was clean but I'm guessing that doesn't indicate much. There was one transom crack that was repair but there is no flex that I could see/feel. The crack repair can be seen in this picture https://www.flickr.com/photos/seanpc...posted-public/ I can't tell if that indicates a deeper issue with the underlying structure or superficial..

[BlueCrab]

quote:

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Originally posted by spc337

quote:

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Originally posted by BlueCrab


I have that same "jelly" on mine. Looks pretty gross[xx(]

I am going to attempt to remove my T-Top and console in one piece this winter and replace tank and probably foam. Hopefully I don't need anything else while in there. That's going to cost enough.

---

Given this probably means water is in the coffin - does that imply other likely damage or am I making to much of this? If the tank replacement is something straightforward for a mechanically inclined person to handle then maybe I should negotiate the price down accordingly and move forward if we can reach agreement. I'm just nervous what else this may indicate. I don't want a boat that requires me to cut the deck and get deep into fiberglass repairs/stringers etc.. No time for that unfortunately.

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Not sure about your situation but I am guessing the foam at minimum will need replacing under my tank area. I have suspicions that the boat sank at the dock before I bought it

[thejeepguy87]

Don't know where you are located, but that price is high. There are several in Florida in great shape for $6500 with replaced tanks.

The tank and foam in that area are toast based on that slurry in there.