What does this sound like?

dvndog

Seaman Apprentice
Joined
Mar 11, 2006
Messages
31
I have that 85 90 johnson with vro going, at low idle since I owned the boat for the past 2 years it runs rough I havent decarbbed but I have been running seafoam in the gas pretty much for a year. I noticed fishing on the water today that when the trim is half way up or more it runs alot smoother, then when I trim down for tqking off it starts to run sluggish until I give her more throttle. It almost seems like the floats in the bowls are sticking? Any Ideas are welcome.

Thanks
 

jammer

Petty Officer 2nd Class
Joined
May 19, 2007
Messages
110
Re: What does this sound like?

I have that 85 90 johnson with vro going, at low idle since I owned the boat for the past 2 years it runs rough I havent decarbbed but I have been running seafoam in the gas pretty much for a year. I noticed fishing on the water today that when the trim is half way up or more it runs alot smoother, then when I trim down for tqking off it starts to run sluggish until I give her more throttle. It almost seems like the floats in the bowls are sticking? Any Ideas are welcome.

Thanks

Now for my 150..if I am going out from the sandbar...and the motor is trimmed up...it runs smooth..but when I trim down getting ready for take off...it does run alittle rougher...so I do give mine a bit more gas and it is fine. For me I thought the prop was just getting more of a bite to it.

Also for me..when my VRO was going I replaced it.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: What does this sound like?

what are your idle rpms, when the motor is all the way down in the water? the is more load on the engine then. have you check your compression?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,994
Re: What does this sound like?

When my motor is trimmed all the way down, more vibration is transmitted to the boat, due to some metal to metal contact in the clamp bracket. If I trim up a bit, the motor sounds like it is running much smoother (it isn't, of course).
 

hoeser

Petty Officer 1st Class
Joined
Jun 18, 2006
Messages
253
Re: What does this sound like?

Most engines will run smoother when tilted up, there is less back pressure on the exhaust. It's almost like running on muffs.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,994
Re: What does this sound like?

Hoeser, I only need to trim the motor a fraction of an inch to reduce the vibration transmitted ot the hull. I doubt it is enough to change the back pressure.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: What does this sound like?

Do you get the same effect with it idling on muffs?

Does the fuel line hold pressure?

When you tilt the engine all the way up far as it will go (engine off), does gas run out the carb throats? How about if you squeeze the primer ball, will gas run out the carbs?
 
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