1978 johnson 115 choke upgrade

[bb1111]

Hello,
I have 78 115 that is a real bear to start. I have been doing a bunch of reading and see reference to upgrading the choke with a newer primer injector setup that post 1980 motors have. Has anyone done this and can you point me towards any documentation on how this is done? All the forum posts i have seen on it say how easy it is but nobody gives any details on the procedure etc.

 

[interalian]

I did it on my '79 140 carbs. You need the small jet/nipple off a newer carb, then drill a passage in the carb at the right angle and size. You will also need the solenoid and lines off a primer system, along with the fuel line "T" that has two large and one small nipple. The primer wires up to the same wire that feeds your current choke solenoid. You may also need the bypass cover off a newer motor that has the mounting lugs for the primer cast in.

That said, choke flappies should work fine if the mechanism is properly set and free to move.

 

[bb1111]

Thank you for the response, that is really what i needed.. i couldn't wrap my head around how i would connect the new solenoid to the carbs. I don't know if I would classify the mod as "easy" but certainly straight forward. I think i will try to get the current setup dialed in and see if that will help. I don't think the butterfly's are fully closing etc. Much appreciated.

 

[F_R]

The original choke should work fine if properly adjusted. I actually prefer it over the primer, but that's just me.
AND you need to give it some throttle (warm-up lever).

 

[bb1111]

thanks.. i will take another run at it. The motor is on a pontoon boat and i can't see the motor from the controls. Makes trying to adjust it pretty tricky doing it solo. I can hear the choke click so i know it is engaging. I will get another set of hands on the controls so i can see what is happening.

 

[interalian]

You shouldn't need to energize the choke solenoid to be sure the mechanism is working. Just manually depress the plunger and see if everything is moving freely and that the flaps close fully. If you can hear the solenoid 'snap' when you hit the key, you know it's pulling.

 

[racerone]

If a V-4 is hard to start maybe there are other issues and it is not going to help by installing the primer.----Simple trouble shooting needs to be doe.-----Slow cranking is a cause of " hard to start " condition.----Take starter apart for inspection = no money spent.----Have battery checked and load tested = no money spent at most auto supply stores !

 

[bb1111]

I didn't think about just depressing it manually i will try that. Everything else seems to be fine, it turns over well and if i manually close the choke butterfly's she will virtually fire right up.. obviously that is a huge pain on the water to remove the cowling get her running then run back and button everything back up. I have only had this motor out a few times and once running it runs great. But even after hot she doesn't want to fire unless i fully close the choke. Hoping getting it adjusted will do the trick. Thanks for all the advice guys i really appreciate it.

 

[racerone]

Sounds like you need to adjust the solenoid to hold choke flappers firmly shut.---Adjust a wee bit at a time.

 

[bb1111]

Well I was able to adjust the solenoid. It was indeed set too low and the flaps weren't closing all the way. I am happy to report that after adjusting correctly the motor is starting great. Thanks again for all the advice.

 

[interalian]

Good news! Happy boating.