do engine bolt patterns change?

[limitout]

does the bolt pattern change on outboard motors depending on the size or brand or is it a set standard size pattern no matter what size the motor is?

im wondering if a 1998 year 25hp will fit a boat with a 2002 year 40hp bolt pattern drilled in it.

 

[H20Rat]

Re: do engine bolt patterns change?

At least in my experience, you can assume its going to be different. You might get 2 to line up, but never 4.

 

[smokeonthewater]

Re: do engine bolt patterns change?

the answer is "it depends".... newer BIA and certain older johnnyrude are the same.... some older and some smaller engines are different

What is every1's outboard bolt patern? - The Hull Truth - Boating and Fishing Forum

Engine Mounting Bolt Pattern - The Hull Truth - Boating and Fishing Forum

 

[GA_Boater]

Re: do engine bolt patterns change?

There is a standard pattern that was established off of an older Evinrude. Happened sometime in the 80's. A little bit of talk about it here - http://forums.iboats.com/non-repair-outboard-discussions/outboard-mounting-bolt-pattern-599362.html

It's going to to depend on what year the two motors are.

 

[limitout]

Re: do engine bolt patterns change?

There is a standard pattern that was established off of an older Evinrude. Happened sometime in the 80's. A little bit of talk about it here - http://forums.iboats.com/non-repair-outboard-discussions/outboard-mounting-bolt-pattern-599362.html

It's going to to depend on what year the two motors are.

ok so as long as im talking about only outboard motors from say 1998 till now or motors built within the last 15 years then they should be the same?.

I have no expectations of any motor older then a 95 or so to put on it and most likely something 10yrs old or less.

I was just mainly unsure about if anything changed from the motors hp size when you got down to something like a 25hp motor.

so I was unsure if there as something like a different bolt pattern for full size motors 75hp+ then one for mid size 70hp-40hp and another for small motors like 15hp-35hp

 

[AChotrod]

Re: do engine bolt patterns change?

Not sure but I would like to know if I upgraded my 95 Merc 60 to a 90-115-125 Merc if I would have this problem.

 

[limitout]

Re: do engine bolt patterns change?

Not sure but I would like to know if I upgraded my 95 Merc 60 to a 90-115-125 Merc if I would have this problem.

based on the responses above I would think you should have no problem with that.

http://forums.iboats.com/non-repair-outboard-discussions/outboard-mounting-bolt-pattern-599362.html

the concerns I had was if I go smaller in HP, I didn't know if the mounts where also smaller or if they kept the same bolt patterns because I just pulled a 40hp off my boat to use on another one and now I want to sell the boat so my neighbor has a 25hp evinrude he wants to sell so I thought If I could throw his motor on my bolt without needing to drill new holes it works best for both of us and the boat and motor together should sell much quicker then a boat without a motor.

 

[GA_Boater]

Re: do engine bolt patterns change?

Why not just grab a tape measure, take your measurements, go over to the neighbor and compare?

 

[AChotrod]

Re: do engine bolt patterns change?

Thats great news. Im not in the market yet but if something happens to mine Im sure I will upgrade. Thanks for the link.

That deal should work out well for you guys.

 

[limitout]

Re: do engine bolt patterns change?

Why not just grab a tape measure, take your measurements, go over to the neighbor and compare?

because it depends on him, its at the deer camp and he wasn't going to bring it home unless he was sure it was worth the effort and im not getting into the discussion of why he didn't want to bring a tape measure hunting with him lol.

suffice to say with this info im going to get a cardboard cutout for him to bring to camp to match it up. I just wanted to know if it was worth going dumpster diving for a cardboard box or if someone here could simply answer the question for me.

That deal should work out well for you guys.

I hope so and I hope he has a gas tank for it so I can run the boat for a potential buyer, I just hate to be dependent upon others for doing my own business.

 

[roscoe]

Re: do engine bolt patterns change?

ok so as long as im talking about only outboard motors from say 1998 till now or motors built within the last 15 years then they should be the same?.

I have no expectations of any motor older then a 95 or so to put on it and most likely something 10yrs old or less.

I was just mainly unsure about if anything changed from the motors hp size when you got down to something like a 25hp motor.

so I was unsure if there as something like a different bolt pattern for full size motors 75hp+ then one for mid size 70hp-40hp and another for small motors like 15hp-35hp

Your 25 and 40 are not the same.

40 hp thru about 200 hp are going to match up

 

[limitout]

Re: do engine bolt patterns change?

Your 25 and 40 are not the same.

40 hp thru about 200 hp are going to match up

ok so I see what it is now, I had forgotten about the twist clamps used on small motors so there is only a 2 bolt mounting pattern used for smaller motors? (he sent me a cell phone picture of the motor) I feel so silly for asking such a dumb question when it should have been so obvious to me :frusty:.

that suks because I had hoped it would just bolt on.

in case anyone else is curious, any motor with those clamp on mounting screws uses only two bolts more centrally located on the mounting bracket so in order to use it on my boat i would have to fill in the old mounting holes and drill 2 new holes. at least they are far enough apart so it doesn't overlap.

:grumpy: damn, I wanted to offer it as a package but I would hate to go through all the trouble to patch the 4 holes and drill new holes to mount the 25hp motor only to maybe have someone not be happy with a 25hp and want a bigger motor.