Pulse limiter change 115 Johnson

goblerblaster

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My Clymer repair manual says to change out the pulse limiter if you replace the VRO, but does not say why that is needed. If you take off the VRO to repair the fuel side, can you continue to use the existing Pulse Limiter ? Is it just a "good idea" to replace it or is it a "must do" ?

Also, the manual has a picture of the VRO and says to "never seperate these parts". The picture is of the oil pump and the electrical input that connects to the oil pump. I need to do just that coz I have one VRO that the oil pump works but not the gas pump, and another that the gas works but not the oil. Any problems combining the two?

I am about sick of messing with the VRO on this motor. Is there any way to just put some type of electric fuel pump from Autozone on it, premix the gas and oil to 50-1, and be done with it?
 

bob johnson

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Re: Pulse limiter change 115 Johnson

put the VRO pump, that the gas side works , on your motor, plug up the hose for the oil intake. and premix your gas , and you are all set...disconnect the electrical from the oil tank.

in 1996 and or 1997 they made a 105 hp commercial motor that did not use the VRO system...it used DUAL regular style fuel pumps.

bob
 

Faztbullet

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Re: Pulse limiter change 115 Johnson

Just take it(VRO) apart and pull the oil pump shaft, the go to premix like Bob posted.
 

goblerblaster

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Re: Pulse limiter change 115 Johnson

Just take it(VRO) apart and pull the oil pump shaft, the go to premix like Bob posted.

Im getting no gas to the carbs, The VRO is full of gas when I take it off. It is getting oil too,just not getting to the carbs, Could this be lack of vacuum thru the pulse limiter? Before I took the VRO apart, the motor wud run as long
as I pumped the primer bulb. Now it will not deliver gas to the carbs. There are no air leaks, etc. If I suck on the hose from the pulse limiter, it feels a little constricted, but not bad. If I blow on the hose from the VRO to the pulse limiter , it blows freely.

Surely there is a way to bypass the VRO with an electric fuel pump and premix gas??
 

goblerblaster

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Re: Pulse limiter change 115 Johnson

Just take it(VRO) apart and pull the oil pump shaft, the go to premix like Bob posted.

Which part are you taLKING ABOUT? tHERE AR SEVERAL ON THE LINK U SENT. i AM NOT GETTING GAS TO THE CARBS. Does that not indicate that the fuel side of the VRO is not working? I have taken it apart and can see no problem with broken diaphgram or anything. This VRO was replaced less that 2 years ago and only has maybe 20 hours run time on it. I don't mind premixing gas, but I need something that will get gas to the carbs. Any ideas on how to bypass the entire VRO and put in some type of different fuel pump. This darn thing is $450.00, the vapor seperator $650.00, etc. I am ready to bypass all of it if I only knew how !!
 

Faztbullet

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Re: Pulse limiter change 115 Johnson

Get a three legged standard pump like one of these,
You cannot use a regular pump on a 60? motor because of the fuel bracket/vapor separator setup. If no gas is getting to engine either:(A) check valve diaphragm in VRO is swollen(B) air motor side of housing is cracked and leaking or air motor diaphragm is bad (C) oring on oil shaft swollen and has pump locked (see a lot of this) and pumping by hand may allow engine to run on straight fuel.
vro719x632.jpg
 

goblerblaster

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Re: Pulse limiter change 115 Johnson

Thanks...diaphram is good Maybe oil shaft pump. But why would it have run bad and then run perfect after 5 to 10 bulb pumping sessions?? Now , no gas at all to the carbs even when pumping the bulb ??
 

Faztbullet

Supreme Mariner
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15,931
Re: Pulse limiter change 115 Johnson

My vote is the check valve on end of fuel side diaphragm swollen and cannot open and close of fuel inlet from fuel bracket to VRO is blocked. Here is link to how the whole thing works I answered in a earlier post with pictures...
http://forums.iboats.com/showthread.php?t=365244
 
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