1974 Johnson v4 spark plugs

[Jeremy27]

I know this is a topic of many opinions but Im going to throw it out there anyway.I have a 74 johnson V4 115 hp motor.I have a friend with the same motor but a 73.Anyways we took our boats out the other day and at the dock he turns the key and within 3-4 seconds hes running.I have never been able to do this.It takes me 2-3 trys to get started.pull the advance 1/2 way,hold the choke in until it turns over..ect.Takes me a couple minutes.Always starts,but a process every time.I run the OEM champion QL77JC4 plugs...he runs the NGK BZ7HS-10 and he swears that's what it is.Said his did the same thing until he changed and Im starting to believe him.???.I have 120 psi on all heads,rebuild carbs every other year,clean them after every 2 months,new fuel pump.reeds look great,coils ,power pack,stater,head gaskets are all 1 year old.Im in tip top shape!What do you guys think?

 

[randyray41]

$25+- for a set of plugs with the correct gap will answer your question . If they don't work give them to your friend.

 

[emdsapmgr]

It's interesting that the original 1973 factory recommendation for the plug on a 115 was ul-77v-which is still recommended for the 135 that year. Both are gapless plugs. I see now they have changed their thinking over the years and now recommend the plug your are using -common in all the 115 crossflows now. The QL77-JC4.

 

[oldboat1]

Think I would get an adjustable tester, and check spark just to be sure. Additionally, want to be sure the choke plate is actually closing. Choke manually rather than with the toggle switch. Hearing the solenoid click can be misleading.

 

[Jeremy27]

I had the ul77v plugs in it originally aswell as a set of L16V (I think) both ran worse.When I say ran worse i mean starting.Once you were up and running they did fine.The QL77JC4 done much better on both ends,running and starting.The choke works and does fully close.I did re-wire it though.originally it would close when you pushed the key in then kicked to half closed until the engine warmed up.problem with that was it seemed like it wanted to flood so i wired it manually..it only chokes when I push the key in.Ill start and bump it a few times to keep it going.To me it seems like its starving for fuel but if you over choke then it will flood.its a fine line I have to hit for it to start properly.timing maybe?

 

[Bosunsmate]

Could be a few things, maybe your throttle cable is worn and it doesnt advance as much, could just be that your boat sits deeper in the water at start up so therefore more backpressure

 

[racerone]

Facts.-------Does timer base rotate when you operate the fast idle lever ?--------Have you adjusted choke solenoid ?----------Is thermo-electric choke feature still in use ?--------Have you inspected battery / battery cables / starter motor.--------All these can be a factor in the starting of your motor.

 

[Jeremy27]

The thermo has been cut off.it only does a full closed choke when you push in the key.Battery is brand new and well connected.And Yes the timer is advancing when you pull the pick up lever.Also I tryed the ngk spark plugs and to be honest,I seen no change.Its just got me stumped cause once she is up and running she runs like a top..re-starts with no problem.its the initial starting process.

 

[oldboat1]

When you say you wired the choke manually, I think you are saying you rewired the key switch operation of the choke(?) You need to operate the choke manually -- as in pull out a choke knob. This seems to be a hard notion to get across. Even operating with a choke knob, you actually can't be sure the choke plate is closing unless you reach in and push on it with your finger. Based on your poor cold starting, you currently have no reason to believe the choke is operating correctly.

 

[Jeremy27]

no what I mean manually is that with this engine the solenoid (it works) will pull the butterflys completely shut when you push the key in and start.After that the butterflys open a little bit more where it is wired to a thermo switch.once it warms up to a higher temp then the solenoid opens the butterflys all the way.The thermo feat. has been by-passed.when I push the key in they close,when I release the key they open all the way(manually).Reason it was rewired is cause it would flood waiting to warm up with the butterflys 3/4 of the way still closed.

 

[oldboat1]

Don't think I can say it too many other ways. Key switch and solenoid considerations aside, the choke plates must fully close to cold start.

 

[Jeremy27]

They do.Ive taken the cover off and the choke plates close fully every time

 

[Bosunsmate]

try starting it trimmed up a bit, i always do that on mine

 

[Jeremy27]

okay.probably take it out tomm