1993 Johnson 115HP VJ115TLATS VRO bypass

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mick3446

Seaman Apprentice
Joined
Dec 21, 2008
Messages
41
I have a 1993 Johnson 115HP VJ115TLATS that someone had bypassed the VRO system but is still using it to pump fuel...should I remove the old VRO and put a fuel pump on instead? The boat doesn't seem to have the power a 115hp should. It is on a Stratos 274...17ft bass boat with a 13-3/8 x 17 prop and it takes for ever to get on plane and when on plane it only reaches 4500rpms at full throttle and goes about 30mph.
 
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Daviet

Fleet Admiral
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Sep 24, 2008
Messages
8,958
Re: 1993 Johnson 115HP VJ115TLATS VRO bypass

Is the engine running properly, spark and compression OK. You are not turning enough RPM, has the engine ever turned the proper RPM.
Maybe you have a high speed orifice plugged or restricted. You might check with the boat manufacturer and see what size prop they suggest, if the prop is to big you will not get the proper RPM.
 
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boobie

Supreme Mariner
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Nov 5, 2009
Messages
20,826
Re: 1993 Johnson 115HP VJ115TLATS VRO bypass

If you're using the vro for just a fuel pump don't blame it just yet. You could have other probs with the mtr.
 
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mick3446

Seaman Apprentice
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Dec 21, 2008
Messages
41
Re: 1993 Johnson 115HP VJ115TLATS VRO bypass

The engine's compression is 120 across all 4 cylinders and the boat starts right up and runs smooth. Thames carbs were just rebuilt Monday and all the cylinders are get spark...I'm lost to why it feels sluggish. It has a new fuel filter, plugs and wires. When it does get on plan it only gets up to 4500rpms...and I thought it should get to around 5500rpms. When running it a full throttle I can feel it miss but not sure why. If you jave any suggestions I'm all ears. Thanks
 
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mick3446

Seaman Apprentice
Joined
Dec 21, 2008
Messages
41
Re: 1993 Johnson 115HP VJ115TLATS VRO bypass

I can't find anywhere that tells you what the right prop should be...all the sites I Gould just give you a range and the prop I have now it in the mid section of those ranges
 
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Fed

Commander
Joined
Apr 1, 2010
Messages
2,457
Re: 1993 Johnson 115HP VJ115TLATS VRO bypass

It should fly with that prop on it +5500rpm.

Your problems are engine related, getting full throttle at carbs, link & sync, running on 3 cylinders?

It won't be your fuel pump because there would be enough fuel in the carby bowls to hit 5500rpm from a standing start.
 
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