Swap options for 3.0 (140hp)

[skijunk]

I got a 1998 Tracker Tahoe Q5 for free at the beginning of summer. The previous owner left it in the lake in the boat slip and consequently varmints have torn the interior up pretty good and since it wasn't tended to, it was left to fill with rain water up to the engine. Now the engine is toast too. Surprisingly, the floors are in great shape. Basically, I got a nice fold-up tongue with brakes, trailer for free.
The boat has the 3.0 Merc 140 hp engine now. I don't mind the 4 cylinder and I'm fine with putting the same engine back in. But I'm wondering if I could go with a more powerful, reliable direct swap 4 cylinder or maybe a 6 cylinder. The lower unit and outdrive are shot too so changing that to match the swap-in is in the plan.

Thanks.

 

[stonyloam]

Rule number one: There is nothing more expensive than a free boat! Since you know the interior and running gear are shot your main concern will be the hull, which would be the most expensive and time consuming to repair. When you get it home removed the engine cover and any access panels in the deck to expose the stringers, motor mounts and transom as best you can. You will want to drill test holes to look for wet rotten wood. The restoration forum is a good place to look for help there. If all looks good you might be OK. If you find rot, you will need to do some research on what is needed to fix it, and decide if it is worth the time and expense involved.

 

[skijunk]

Motor mounts and stringers look good. Hull is in great shape other than a faded accent color (which I will buff out) , all gauges are in tact but I haven't confirmed their function. . I am no stranger to watercraft. I have had ski boats, pontoon boats and countless jetskis. I've never had to do an engine swap in a boat - quite a few cars but not a boat.
Nothing I ever got for free was a good deal! lol

 

[stonyloam]

If you can do a car engine, a boat is a piece of cake, just have to find a higher tree limb. Once you get the engine out, check the transom for rot around the cutout and drain. As far as the engine swap goes, that sort of depends on the boat. If it is small, like a 17' you will need to take into account that a 6V will weigh about 200 pounds more than tha 3 l. On a larger boat the extra weight should not be a problem. You will need to fabricate new mounts for a 6, another 3l will be a drop in.

 

[Scott Danforth]

I would verify if your drive is shot. Of so, then swapping in a complete V6 long tail would only require fabrication of new front mounts.

 

[skijunk]

If you can do a car engine, a boat is a piece of cake, just have to find a higher tree limb. Once you get the engine out, check the transom for rot around the cutout and drain. As far as the engine swap goes, that sort of depends on the boat. If it is small, like a 17' you will need to take into account that a 6V will weigh about 200 pounds more than tha 3 l. On a larger boat the extra weight should not be a problem. You will need to fabricate new mounts for a 6, another 3l will be a drop in.

The weight is a concern too. I think the boat is like 18' and I would hate to do the swap only to find that with 6 people in the boat and a skier in tow that I have to work to get it to plane out

 

[skijunk]

If you can do a car engine, a boat is a piece of cake, just have to find a higher tree limb. Once you get the engine out, check the transom for rot around the cutout and drain. As far as the engine swap goes, that sort of depends on the boat. If it is small, like a 17' you will need to take into account that a 6V will weigh about 200 pounds more than tha 3 l. On a larger boat the extra weight should not be a problem. You will need to fabricate new mounts for a 6, another 3l will be a drop in.

Yeah, I don't think my cherry picker has an arm long enough to get the engine over the transom..

 

[skijunk]

I would verify if your drive is shot. Of so, then swapping in a complete V6 long tail would only require fabrication of new front mounts.

I believe the outdrive is shot and the skeg has been ripped off and the prop is mangled which is probably a hint to the demise of the ourdrive. The bellows are trash. None of this scares me but I am not delusional either. It's gonna take a fair amount of work just to get it back on the water.

 

[wahlejim]

Try an SEI outdrive, cheap and work fantastic! The 4.3 and 5.0 were engine upgrades offered with that year and model, so unless your USCG plate says differently, upgrading shouldn't be a problem.

 

[skijunk]

Try an SEI outdrive, cheap and work fantastic! The 4.3 and 5.0 were engine upgrades offered with that year and model, so unless your USCG plate says differently, upgrading shouldn't be a problem.

Ok - great... I'l look into it. Do you happen to know if the bellhousing on the 3.0 is a direct bolt on to the Merc 4.3 v6 ?

 

[Scott Danforth]

Ok - great... I'l look into it. Do you happen to know if the bellhousing on the 3.0 is a direct bolt on to the Merc 4.3 v6 ?

Get a complete long tail from controls to prop vs trying to piece something together

 

[skijunk]

Get a complete long tail from controls to prop vs trying to piece something together

This is where these forums come in handy'; I wasn't even taking into consideration that I would have to change controls. Thanks !

 

[Scott Danforth]

You shouldn't need to, however it's better to have everything you need as a package.

I would look for a wrecked or rotten boat as a donor

 

[Rick Stephens]

Take apart and make certain your current 3.0L is in fact shot. They can be resurrected from a lot of water damage depending on how long and how high the water level was. If nothing else a good 3.0L block is sellable. Hard to destroy a block submerging them, easy freezing them.

 

[skijunk]

Take apart and make certain your current 3.0L is in fact shot. They can be resurrected from a lot of water damage depending on how long and how high the water level was. If nothing else a good 3.0L block is sellable. Hard to destroy a block submerging them, easy freezing them.

As always, the first thing I did was take the plugs out and when i did rusty water ran out of each hole. I filled each cylinder with penetrating oil and let it sit for about a month. It still won't budge. I guess I could salvage a few pieces off of it

 

[Rick Stephens]

As always, the first thing I did was take the plugs out and when i did rusty water ran out of each hole. I filled each cylinder with penetrating oil and let it sit for about a month. It still won't budge. I guess I could salvage a few pieces off of it

Yeah, I have been there. I bought a boat with a zero hour rebuilt 4.3L in it. They had pulled all the flooring out and left the new motor in with no flame arrestor on the carb. The tarp thrown over the top ensured that at least condensation dripped in and filled a couple cylinders. I did the same thing, filled with Marvell Mystery Oil and cranked the motor with a bar and a couple long bolts through the flywheel coupler mounting holes. Was able to finally work it out. Then pulled the motor down and had it bored an additional .020 to .040, replaced pistons and rings and rebuilt it again. Runs perfectly now, but a tough job. On your motor, I would tear it down and drive the pistons out from the bottom if I had to.

Rick