1987 110 HP V4

[imported_scott_m]

Hi, I'm posting for my father-in-law (FIL) and brother-in-law (BIL). I've got mostly mercury equipment (135 on my fishing boat and big block inboards in my cruiser), so not real familiar with Johnson's (although I do have an 8HP on Johnson on the dinghy). Anyway, FIL as aforementioned 1987 vintage Johnson on his 1969 Fabuglass tri-hull. At the end of last season, he was complaining of the motor not having much top end, general lack of power. Over the winter, he took it to the shop - they ran a compression test - I don't have the numbers handy, but comment was one hole was low. I remember calculating the numbers and the low hole was only off say 5-6 percent of the big one. So I suggested he go back to the shop to have them check carbs and timing. Apparently they did rebuild one or more carbs, but the boat is still not running up to snuff. Enter BIL, a great car mechanic, but has not worked much on boats. BIL decides that the fuel pump is bad (I know on the merc's it is a diaphram type pump). Anyay, rather than rebuild stock fuel pump, BIL decides to replace with an electric pump. On my merc, I think the fuel pump supplies air to the oil tank to pressurize it...is it the same with a VRO setup on the Johnson's? FIL did run the boat with electric pump and said it runs great, but I'm concerned that he may be starving the motor of oil. Although I suppose this setup might work with pre-mix. Anyway, interested to hear your thoughts of running this motor off of an electric fuel pump.

 

[OBJ]

Re: 1987 110 HP V4

I think I share your concern about oil starvation but it would depend on where the outlet of electric fuel pump was put and if the VRO pump is still connected to oil or if your FIL disconnected the oil and mixes his own. I don't personnally like electric fuel pumps unless they are made for this type application with certain safe guards like auto shut down if the engine stops.<br /><br />I would question the FIL and BIL about the above. It would seem that since the engine is running better with a sustained fuel supply that the VRO is bad but that's just off the cuff. But I would ensure that the engine is getting adequate oil with the fuel.

 

[imported_scott_m]

Re: 1987 110 HP V4

Thanks OBJ. Last I talked to FIL, he was still using the VRO to manage his oil. Had not even thought about auto shutdown on the fuel pump. Does anyone have a diagram that I could look at for the fuel and oil sysetms for this motor? I'd like to understand your comment about 'where the outlet of the electric fuel pump was put'.

 

[OBJ]

Re: 1987 110 HP V4

Simply put, the gas MUST go through the VRO pump to get mixed with oil if the pump is still being used with the oil connected. The fuel enters the pump at the bottom, is mixed with oil and is pumped out the top of the pump to the carbs. Sorry, don't have a diagram handy.

 

[imported_scott_m]

Re: 1987 110 HP V4

OK, I think I can visualize what you are describing, so I'll pass it along to the FIL/BIL to check out. What about fuel pressure issues? I'm not sure if/what sort of regulator they may have installed with the electric pump. What is the stock pump pressure, and would higher pressure from an electric pump cause problems inside the VRO?

 

[imported_scott_m]

Re: 1987 110 HP V4

Bump.

 

[djzyla1980]

Re: 1987 110 HP V4

What was the reasoning for not buying a stock Pump?????<br /><br />From what I have found.... 4.5-6.5 but this is gunna depend on your motor

 

[djzyla1980]

Re: 1987 110 HP V4

I should add.... hat was for a 70hp vro

 

[imported_scott_m]

Re: 1987 110 HP V4

I think the reasoning for going with the eletric pump was simple...Brother-in-law knows nothing about marine engines...plenty about his SBC in his 4x4, but NOTHING about marine and this was the easy way out. I really wish I could get my hands on it, but father-in-law is up in central TN. I'm guessing the fuel pumps are easy to rebuild on the Johnson's? On my mercury, it's about 10 bucks for a couple of diaphrams and two check valves.