Yamahs 115 V4 outboard

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triple d

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Joined
Jul 12, 2006
Messages
4
I have a problem with low RPMs can't get over about 4500 to 500 and only runs about 30 mph. I've replaced the fuel connector, spark plugs, and over hauled carbs. Starts and idels fine just no power. I also check the prop bushing seem fine. Compression tested at 120 to 125 on all 4 cylenders. Any suggestions?

thanks,
DS
 
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rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Yamahs 115 V4 outboard

what is the normal WOT? have you ever seen it turn up correctly?
you can use the yb1624 test wheel for a power output test to isolate the engine from the hull and prop.
 
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triple d

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Jul 12, 2006
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Re: Yamahs 115 V4 outboard

[quote time1152788877= userrodbolt= uid32169= fid30= tid= rid1= what is the normal WOT? have you ever seen it turn up correctly?
you can use yb1624 yb1624 test wheel for a power output test to isolate the engine from the hull and prop.
[/quote]

5500 RHMs is about 40 RHMs 45 about 40 to 45 MPH. Normally at WOT if your not holding on, you WILL fllor up on hual fllor of the hual! I have since checked the fuel pump, removed the prop found very little crab string and cleared that problem. Runs good idles fine I just Im no power. I'm almost sure it's an electronic problem any idea how I can test the power pack?
 
T

triple d

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Jul 12, 2006
Messages
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Re: Yamahs 115 V4 outboard

5500 RHMs is about 40 RHMs 45 about 40 to 45 MPH. Normally at WOT if your not holding on, you WILL end up on the floor of the hual! I have since checked the fuel pump, removed the prop found very little crab string and cleared that problem. Runs good idles fine I just have no power. I'm almost sure it's an electronic problem any idea how I can test the power pack? Could my power pack be bad with it running and idleing so well?
 
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Ray Neudecker

Lieutenant Commander
Joined
May 25, 2004
Messages
1,656
Re: Yamahs 115 V4 outboard

Very unlikely. Basically check for fire with a timing light or spark tester. If it is there you can almost bet the problem is not electronic. It definitely sounds like you have a fuel restiction.
 
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triple d

Recruit
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Jul 12, 2006
Messages
4
Re: Yamahs 115 V4 outboard

I found the problem! ;) Your correct it was fuel. Somehow a piece of the old "o" ring got trapped somewhere when I rebuildt the carbs it was blocking fuel jet. Back in the water and running like I'm it should. I can hit it and get 6000RPMs in nothing flat! ;)

Thanks so much for the help.
 
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