# 1140cc 90hp Yamaha performance



## semojetman (Apr 19, 2011)

I am rebuilding my 1988 1140cc 90 HP Yamaha outboard.

I have been researching on here and talking to local shops to see what we can do to boost the performance just a little while we have it tore apart.

Here are a few things I'm considering
Boyeson Reeds
Tuner
Hydrotec performance head
Re-jetting

Will most likely do Boyeson reeds and tuner, maybe the head and jetting with time.


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## Lil' Blue Rude (Apr 19, 2011)

Guy here in town named G.W. Lutrell, he builds the fastest outboard jets hands down. You might give him a call and see what he says. 
Boyseens don't seal the best in the world and performance starts to go down hill pretty quick because they start to fray at the ends. You might look at Chris Carson Marine for a set of reeds. I've seen tests running boyseens against Chris Carson reeds and another brand on the Yamaha 90's and the Chris Carson produced the most power and the best pass times and they're cheaper then boyseens. Never heard a bad thing about him. He's a great guy to deal with and he makes a nice set of reeds. If you don't feel like buying a hydro tec head just shave some off of your head, it would be alot cheaper and probably produce the same results.
Rejetting is a must if your adding an exhaust that's going to make any diffrence at all. Most times they need to be fattened up some after you add a tuner because they're lean and you'll burn another hole in your piston.

You might as well polish the inside of your pump while your at it.


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## semojetman (Apr 20, 2011)

Thanks for all the ideas and advice.

Do you have a number for that G.W. Luttrell and where is he located.
I like to meet people in person more than talk on phone.


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## Lil' Blue Rude (Apr 20, 2011)

PM sent


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## turne032 (Apr 21, 2011)

I take it if you sent your motor to springfield HydroTec has it?


I might go over and steal it from them!!!

hahahaha


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## semojetman (Apr 21, 2011)

We've got a pretty good game plan worked up for the ol 90.

We've been on the phone with hydrotech and a few others 

reeds, shaved head, exhaust tuner, and a few other little tricks we got up our sleeves.

We're looking to get right at 8-10 hp over stock.


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## semojetman (May 10, 2011)

The powerhead is on its way back from the machine shop. Ordering reeds, tuner, etc this week.


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## Lil' Blue Rude (May 27, 2011)

How's the build coming along?


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## semojetman (Jun 9, 2011)

going good. taking it slow as my extra finances will allow.

got the powerhead back from hydrotech, got most of the parts for motor.

been working on the boat and trailer a little as well.
*stripped and painted trailer yellow.
*carpeted boat in charcoal carpet
*designed an aluminum gas tank
* purchased marine cd player and speakers
* found some of our old pontoon boat seats that are gonna line up great to make like a bench seat.


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## semojetman (Jul 9, 2011)

Well, she's back on the water. Runnin great.
We did the boreing, Boyeson stage 2 reeds, and Hypertec tuner.

It starts great, runs great and has awesome throttle response but I will still disappointed to see that it still only GPS'd at 30 mph. 

I was stumped by this, why would a 16 foot boat with almost 100 horse only run 30 mph. Well, today I ran with a friend that just bought a brand new 1856 Blazer SS with a new 60/40 4 stroke mercury. 
We ran almost neck and neck, and thats a 30 horse factory difference.
Well, when I went to pull his boat up further on the gravel I figured out why. I guarantee my boat weighs 2 to 3 times more than his.

So hopefully when I move my motor to the blazer hull it will scream.


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## Lil' Blue Rude (Jul 10, 2011)

Glad to see your back on the water. 
100 gauge boat vs. 80 gauge quite a bit diffrent. Think of how it would run on a 17' 48" Blazer SS.


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## semojetman (Jul 11, 2011)

I know. Ive thought about it and I cant wait to find out. My little boat is just so unbelievably heavy


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