Yamaha 115 mods

[Coonnasty]

Didn't see any info regarding this on the website, so hopefully this is the right place for the question/s? Anyway, I've got a 115 yamaha on a 17' Xpress, about to put more money into that hole in the water... What modifications can I do to enhance the performance? I realize that it's just a 115 but once I put the jack plate & maybe a 4 blade prop. What's next? Reeds, milled heads, any type of exhaust modifications or products that I should look at? Or, should i not even bother, is it just opening another can of worms?

[Mike Noble]

This is a good place to ask those questions.  I can't give you answers.  Here are some questions that you answer to help those that know motors.  What size prop, what pitch.  A four blade will probably make it slower coming out of the hole.  A jack plate would probably help.

Good luck.

[Mike Cork]

Ice, I don't have any specifics about a yamaha. But with any motor, you are definately opening a can of worms. The jack plate and prop are your safest bests for trying to increase speed. When you start playing with internal components you are looking at more malfunctions. Yes you will gain a couple mile an hour but you really have to way the costs. When you start changing reeds and doing head modifications, these things are very expensive in their selves, and tend to lead to a much more finicky motor. Meaning everything has to be perfect for it to run right so if you get some slightly bad gas you have trouble. Also, most folks that I know that have changed their reeds out have ended up sucking one into the cylinder, the modified reeds are not made to last a life time, some of the high performance ones need changed every 100 hours, so there you are looking at added expense. Modifided heads will make your motor run hotter and that is never a good thing for a 2 stroke and over time will cause explosive damage.

A modified motor takes alot of TLC, so for a couple thousand dollars and allot of work and rework you get 4 mph. For some people it is worth it. These are just my experiences and most that know me know that "Murphy" of Murphys law is a standard fishing partner of mine, you can never see him but he is always there, and he never contributes to the limit.....

[DundeeMike]

Opening the exhaust will help quite abit. I had a 18 foot skeeter with a 150 Merc. I had the exhaust opened and put in reeds. The boat ran great, and I could keep up with the 200 hp. boys. Sometimes even out running the 200hp's. Never had a bit of trouble with the motor after the mods were done......

[Mike Cork]

There you go, I told you Murphy is always with me!!!!

My post was a little unfair, I should also say that I have blown two top ends, one on johnson 115 and one on a johnson 200. Hum may be there is the problem johnson. Both of these motors were completely stock.

I still love my johnson, what man wouldn't 

[dave the dope man]

I have to agree with Mike's FIRST response. My Grandad was a quiet but wise man, He used to say "the more you  add.......the more there is to go wrong". The jack plate and prop will probably suffice, at first, then if you get the itch for more speed, trade in that new jack plate and prop and go to a larger boat with the performance you want  ( it will also have a warranty ).......My half cent............Dave

[Marty]

There is one thing you can do that will, without risking the reliablity of your stock outboard, do more dollar for dollar than anything else you can do to get more performance out of that hammer.  Contact Rich Boger in Texarkana.  His website is www.bogerprops.com  He is widely regarded at the prop expert extraordinare.  He does magic with props that no one else can, and you can expect to have a significant improvement in your boat's overall performance after you get your prop back from Rich.  He will ask you for specics, like your boat & motor models, your max rpms now, questions about hole shot etc.  It will cost you a couple hundred $$, but like I said, you will get your money's worth.  There are people closer to home who do prop work, but trust me, Rich Boger is the MAN!  One thing, you will have to send your prop to him, he doesn't do walk-ins.  One other thing, Rich is a fine, patriotic American vet, former Navy Seal and is a man of his word.  He will tell you exactly what he will do for your prop & your boat's performance.   He will shoot straight with you on all counts.  If I bought a new prop today, it would go to Boger immediately!