reverse engineer the primer solenoid on a V4 85hp

[spybot]

I want to move a V4 115hp choke solenoid carbs to a V4 85hp primer solenoid set up.
I have a primer solenoid (from V4 85 hp) that i want to fit on to a V4 115 (Choke solenoid) and vice versa.
Can anyone explain what i have to do to fit choke carbs to a previously choke primer motor.
Obviously the carbs, bypass covers and intake (the choke solenoid sits at the top)
Do i change the whole intake manifold?
Is there a big difference in the throttle linkage ?
How far out will the jetting be from the 115 to the 85 ?
Which carb is better ?
Andy

 

[jakedaawg]

Well, right off the bat you will have to mill a hole behind the throttle plate and install a nipple.

the throttle butterfly will also need some modification as I would think it will need a hole.

but first, why reinvent the wheel??? Make sure that what ever Franken motor yo uh are putting together will run and perform the way you expect before worrying about the little stuff.

don't get me wrong here, I believe in mods to increase performance and have many under my belt...but yours seem to be a mish mash of old stuff just to have a motor. If that's the case it's always easier to find a donor boat with a fixable motor that you want than it is to combine a bunch of stuff...much less will be spent.

 

[spybot]

Jakedaawg I have found a 115 that i want keep thing is it has choke plates rather than the primer solenoid.
I like the primer so i want to take it off my 85 and fit it to the 115. But i dont know how to do this.

 

[racerone]

Look at the bits and pieces and swap it over.-----It is so easy .----I have installed this system on a MERCURY outboard.----Simple to do when you understand how it works I guess.

 

[spybot]

I have the full inlet manifold that i can change over. Will this just be a case of bolting the whole thing over ?
Like you Racerone i to dont mind spending 110 hours on an old engine

 

[Tagged]

You’ll also need to T into the fuel line between the fuel pump and the carbs to run a fuel line to the primer, and run two fuel lines from the primer to the carbs.

Then you’ll have to drill and tap a port into each carb behind the butterfly.

 

[spybot]

Tag i have the full fuel system. All hoses bypass covers inlet manifold with as you said puddle drains ect ect.
I think it would be a straight swap Carbs and inlet manifold plus hoses ect
The system on mine does not pump fuel to the carbs like some mine pumps fuel from the primer directly in to the cylinder through the nipple on the bypass cover (the same nipple you guys have on the carbs.
The engine starts right up almost like a fuel injected motor.
I dont know why they changed it to the carbs. Mine is one of the first model to have this and i want to keep it.
I just wanted confirmation before i start

 

[racerone]

???----They often make changes to reduce manufacturing / assembly costs.----Has nothing to do with the way it works from one set-up to another.------Take the time to learn how the electric valve operates and how that works instead of choke flappers.----Then installing that electric valve / primer on any motor will be simple..

 

[spybot]

I will have to look into this in detail, but i think the primer once activated opens a valve that lets fuel through to the by pass covers and into the block. This is pumped via the vaccum that is caused by the piston ?
Am i close ?

 

[racerone]

??----No the valve gets pressurized fuel from the hose between the fuel pump and carburetors.----This fuel is then sprayed into the motor when valve is opened.----At the bypass covers or nipples on carburetors, no difference. ----Suction of pistons has nothing to do with getting that fuel out of the wee hoses.

 

[Chinewalker]

Hmmm. Never seen one rigged to go to the bypass covers. The nubs on the bypass covers are usually plumbed to recirculation hoses to get rid of puddled fuel in the crankcase. Every original crossflow V4 I've dealt with that had the primer system had it going to the top of the carbs, aft of the throttle plates.

 

[spybot]

Hmmm. Never seen one rigged to go to the bypass covers. The nubs on the bypass covers are usually plumbed to recirculation hoses to get rid of puddled fuel in the crankcase. Every original crossflow V4 I've dealt with that had the primer system had it going to the top of the carbs, aft of the throttle plates.

There is hoses from the bottom of the intake where the reeds are to get rid of the fuel. These also go into the bypass cover

 

[racerone]

??---Correct the early primers used fittings on the bypass covers right from the factory !!

 

[spybot]

Yeah my motor was one of the first to have them. My engine was number 601
They changed the set up the following year maybe even the same year at the tail end.

 

[spybot]

??----.wee hoses.

Scottish background Racerone ?