Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

[ondarvr]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

I recently got bids on insurance, no companies turned me down for having more HP than the hull was rated for (rated for 150 with a 200 on it), I didn't hide this and I assume they added an up-charge for it if they were concerned.

Plus the Coast Guard does not ticket or fine you for having exceeded the HP rating, they are only concerned if you operate the boat recklessly, or it appears to be unsafe.

Local laws may regulate this, so you need to check. I don't in any way say its a good idea, and you need to be the one to make the final decision because only you can see the boat and motor to tell if it will be even somewhat safe.

 

[jay_merrill]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

IMO, the manufacturer already gave you all the advice that you need on this matter - its on the boat's rating placard.



???

 

[Scisor34]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Not that it guarantees no accidents, but if you're an experienced boater I say go as big as you want. Some of my fondest fishing trips were in a buddy's 17.5ft Lund Tyee with a mod 225. Talk about fun and in such a sleeper package. The factories under rate these boats because of lawyers

 

[ezmobee]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Your boat should be performing much better than it is with the current motor. Might want to look into that first. You've practically got the max rated HP on there now and should be seeing closer to 40MPH. Motor needs a tune up, different prop, or the boat has waterlogged foam. Thundercrafts were entry level boats and would not be my first choice for overpowering.

 

[wca_tim]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Its a waste of time. Its a Force 125, so it will only be running on 3 cylinders most of the time anyway. So you will only be getting 90 hp in the end. hehehe

bwa ha ha ha.... definately something to consider!

 

[hunterfab]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Inspected the prop this morning and found about a dime size chunk taken out of the edge of prop blade I am also wondering if my prop isnt spun or slipping on the hub.. Dont think its waterlogged it does have a new floor and stringers.. So at this point I am stumped! The best I could get out of it ar 5500 rpm with the motor at full trim was just a tic under 35. After sleeping on it and reading the "rave" reviews on the force 125 I think I am going to find something in the 100-115 range and go with that.. The motor currently on the boat does run really well and does not seem to have any problems no misses,starts at the touch of the key and is easy on fuel! I am gonna run just regular 85 octane fuel through it instead of 91 and see if that makes a difference. Actually read about that somewhere else in this forum!

 

[dorelse]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Well, if you've already got the 125, might as well put it on. I have had good experiences with Force outboards, others have not. They do like to be taken care of...that's for sure.

 

[hunterfab]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

OK found the problem!! GRRRRR inspected the hull and found several holes in the gel-coat!!! I removed the hull plug and tons of water came gushing out! I now have the front of the boat cranked way up in the air with a couple of cinder blocks under the trailer jack and its still coming out.. My next question is how to patch it? Looking at it it looks like there is a outer hull and a inner hull behind it not sure I can get to it by pulling the floor. Under the boat down the center of the hull about midway its also worn through to the inner hull.. Any ideas on how to repair it?

 

[Shife]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

OK found the problem!! GRRRRR inspected the hull and found several holes in the gel-coat!!! I removed the hull plug and tons of water came gushing out! I now have the front of the boat cranked way up in the air with a couple of cinder blocks under the trailer jack and its still coming out.. My next question is how to patch it? Looking at it it looks like there is a outer hull and a inner hull behind it not sure I can get to it by pulling the floor. Under the boat down the center of the hull about midway its also worn through to the inner hull.. Any ideas on how to repair it?

How long have you owned this boat?

 

[hunterfab]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Have had it about 2 months and its been on the water twice..

 

[Shife]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Have had it about 2 months and its been on the water twice..

You do know that you're supposed to pull the drain plug when the boat is out of the water, right? If that hull has been partially full of water for two months it has now worked its way into every bit of wood it could find.

If you don't know exactly the condition of the stringers and transom core, I would be pulling up that floor decking and having a closer look before throwing any power at this thing. If the PO banged up and damaged the hull to the point where water is seeping in, I doubt very much that the repairs he/she made were of anything you would want to trust. Otherwise they would have fixed those issues while the boat was apart. Most likely a band aid to make it just saleable enough for a new sucker...er, owner.

 

[hunterfab]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Yeah I know you are supposed to pull the plug after use.. What I meant was is that I removed the fitting the plug goes into and water came out from inside the hull! Not the bilge.. The boat was in storage for 3 years and was only on the water twice in the last 2 weeks.. Am going to patch the holes and leave it tipped up for awhile and let it drain then hope for the best! Explains why I could only get a tick below 35 outta this thing! Should have crawled all the way under it before I bought it but hindsight is 20/20 at least I dont have a ton of dough wrapped up in it!

 

[smokeonthewater]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

from what you said I'd say that hull isn't worth repairing..... Get on craigslist and find yourself another hull for cheap.... then hang the merc on it and go..... I personally would sell the force to fund the new hull

 

[a70eliminator]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

You were actually reaching 35 with a hull full of water!
Heck my 16' 80hp can't do that, yours must be a go fast hull design like low and sleek?

 

[dwco5051]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Pennsylvania Fish & Boat Code;

Reckless and negligent operation of watercraft - 30 Pa. Cons. Stat. ? 5501

(d) Exceeding capacity prima facie evidence of negligence.-- Exceeding the loading and horsepower limits for a boat as provided on the capacity plate issued for the boat is prima facie evidence of negligent operation of the boat.

A person who violates this subsection commits a summary offense of the first degree

 

[old-gubbins]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

How about:
Repair hull, repair prop, see how she goes with existing motor. If she still pulls 5.5k but motor is 6krpm max, you can try a lower pitch prop to improve hole shot, also is motor high enough on transom?

Plenty of guidance on here about repairs. I would repair externally, grind out the damaged area with a gradual taper from thin at the hole to thick/unground at 3" away, repair with polyester resin, laying up graduated size layers of glass to surface level, lots of rubbing down/filling to get it level and smooth then gel coat or paint to finish.

If still disappointed with the performance ( or you really want to change anyway ! ):
Tell insurer what rating is, ask if they will insure with the proposed over-rated engine. If answer 'yes', tell state this and ask if acceptable to them. If either say 'no', don't do it!

I have a boat rated for 50hp, wanted to fit 60hp, Insurer was happy, so I changed it, but I asked first!

Good Luck,

O-G

 

[Shife]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

How about:
Repair hull, repair prop, see how she goes with existing motor. If she still pulls 5.5k but motor is 6krpm max, you can try a lower pitch prop to improve hole shot, also is motor high enough on transom?

Plenty of guidance on here about repairs. I would repair externally, grind out the damaged area with a gradual taper from thin at the hole to thick/unground at 3" away, repair with polyester resin, laying up graduated size layers of glass to surface level, lots of rubbing down/filling to get it level and smooth then gel coat or paint to finish.

If still disappointed with the performance ( or you really want to change anyway ! ):
Tell insurer what rating is, ask if they will insure with the proposed over-rated engine. If answer 'yes', tell state this and ask if acceptable to them. If either say 'no', don't do it!

I have a boat rated for 50hp, wanted to fit 60hp, Insurer was happy, so I changed it, but I asked first!

Good Luck,

O-G

The stringers and transom are rotten/watelogged. There is no repairing this from the outside. The hull either needs to be stripped and rebuilt or cut up and thrown in the dumpster.

 

[Stachi]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Its a waste of time. Its a Force 125, so it will only be running on 3 cylinders most of the time anyway. So you will only be getting 90 hp in the end. hehehe

I resent that ! ... ( look at my boat below )....

 

[Stachi]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

I have finally finished removing all of the WATER LOGGED FOAM , from the bowels of my boat...1990 Bayliner 20' CuddyCabin w/ '89 Force 125..... I'm guessing I lightened her by somewhere over 500 lbs.
When I removed a fist sized chunk of foam, water would RUN , not drip from it when I squeezed it.... this boat has been under cover for a year now...hasn't even been in the water since 1997....every place the foam was in contact with wood, was sopping wet , and the wood was rotten......
Either do the restoration , or find another hull.... sometimes I see boats on Craig's list , where the owner gave up on a hull after doing all of the demolition of the deck and just wants to get rid of it.This isn't always a bad start of a boat project...all the itchy work done for ya !...lol.... If your budget only allows for a boat of that vintage ,.... it's gonna be hard to find one without that kind of damage. Good luck with whatever you decide to do , and welcome to iboats forums!

 

[hunterfab]

Re: Bigger engine swap.. Want to exceed manufacturers rating..Advice please.

Patched the holes from the bottom and am gonna finish pulling up the floor and checking the stringers and insides today! Am wondering about the foam though.. After I pull it out how in the hell do I replace it? Am also gonna patch from the inside also! Gonna itch for days after this one!!