70HP JOHNSON IDLE PROBLEMS............already paid for boat and slip

[ScottWyler]

Good morning, new to the forums and new to the boating world. I just recently purchased an 88 starcraft that came with and 89 johnson. My first boat. I put the boat in the marina and paid the marina already for the slip for the summer season. My one and only problem is..I cant even pull the boat of the slip because the motor is not running properly. My boat has two throttles. One is the throttle shifter and the other is a lever next to it which controls the idle. I was told from the previous owner that when starting the boat, put the lever up high and then when she starts, lock the lever down in place. It works, starts up right away! When the idle lever is high the motor is screaming way to high! When i lower the lever, and lock it in place the idle is def. too low and she stalls every time. This is unfortunate because now i cant even pull out of this spot to drive my boat for the very first time and it is a bit frustrating to me. So i assume since the idle lever is too high, motor is running way too high, and when the lever is low in place its too low and the motor then dies out. I am aware that there is a screw for adjustment and im hoping that my problem is only a quick tune or adjustment and im not that screwed! and help is appreciated and thank you all for helping and reading this!!!

 

[Chinewalker]

Don't worry about the high idle bit - just don't lift the lever that high when starting. As for the low idle, there is a stop screw on the starboard side of the motor that can set the low idle point. I believe it should fall into the 500-700 RPM range at low idle, in gear, but someone can correct me if my memory is off...

 

[flyingscott]

Give us your cold start procedure I think you may have more of an issue with your starting procedure. The small lever only controls the idle for warming you shouldn't be pushing it all the way forward just a little like you were told in the last post. Are you letting it warm up or just slamming the lever down right away because after the motor starts you need to let it idle at about 1500 RPM for a couple minutes, before you put the lever all the way down.

 

[ScottWyler]

Give us your cold start procedure I think you may have more of an issue with your starting procedure. The small lever only controls the idle for warming you shouldn't be pushing it all the way forward just a little like you were told in the last post. Are you letting it warm up or just slamming the lever down right away because after the motor starts you need to let it idle at about 1500 RPM for a couple minutes, before you put the lever all the way down.

I let it idle for like 5 minutes and then i slowly drop the lever. but she still stalls on me......so frustrating.

 

[ScottWyler]

Cold start procedure is basically, key in the igntion pushing it in while turning it to the right which is a choke procedure i guess.....lever is like half way high up....before i start it though i pump the ball and prime 4 times.....let it warm up for five minutes and then slowly gradually drop the lever until its in place. she idles low and then like 30 seconds or less shes dead and stalls when that lever is in place....

 

[flyingscott]

Do a spark and compression test before you adjust the idle did you test drive the boat before you bought it

 

[kax2000]

Since it is "new to you" get it set right to begin with. You won't go wrong with doing a "link-n-sync". Get the service manual...it is worth every penny.

 

[ScottWyler]

Okay, awesome thank you. The boat neighbor next to me told me that its just an old motor and basically he said I just need to goose the gas a bit more than normal in order to really get out of the spot and thats really it. I got the motor running better with the idle screw adjustment. is this true what my neighbor said?

 

[flyingscott]

No your neighbor is not right I have a similar motor and once it's warmed up I can idle out with it. Your supposed to set the idle warmed up and running in gear. They don't idle really well so your idle in gear will depend on the motor. The lowes I have ever got one to idle is 850 RPM in forward.

 

[ricohman]

If the idle jets are plugged in the carbs, no amount of adjusting the idle lever will cure it. By moving the lever all the way forward you are simply going onto the high speed circuit. And when you drop the lever down the engine will stall.
Its not a difficult job to do and carb removal could be done in the water if there is no way to get the boat out. Just don't drop any anything.

 

[ScottWyler]

If the idle jets are plugged in the carbs, no amount of adjusting the idle lever will cure it. By moving the lever all the way forward you are simply going onto the high speed circuit. And when you drop the lever down the engine will stall.
Its not a difficult job to do and carb removal could be done in the water if there is no way to get the boat out. Just don't drop any anything.

so the adjustment of the idle screw is not or does not have anything to do with my problem here im guessing? what exactly should i do or what exactly do you recom

 

[Chinewalker]

so the adjustment of the idle screw is not or does not have anything to do with my problem here im guessing? what exactly should i do or what exactly do you recom

It may. It may not. Who knows what prior owners have done to it over the years. As noted above by others, it's a good ideal to check the basics and make sure it's running properly on all three cylinders. Good compression, good spark, and fuel delivery will do the job.

 

[oldboat1]

maybe an 18' Starcraft -- probably a tank across the transom. If it's got a water separating filter, unscrew the canister and empty it into a glass container (look for water) -- and replace the canister/filter. Kind of tough to mess with fuel issues at a marina, as they are skittish (reasonably) about boaters torching the place. But will want to insure that you have fresh fuel (at least no contaminated fuel). Can get some background and tips from slipmates at the marina too -- learn as much as you can about prior use.

 

[ricohman]

so the adjustment of the idle screw is not or does not have anything to do with my problem here im guessing? what exactly should i do or what exactly do you recom

Cranking up the idle will not cure plugged low speed circuits. If this motor has to idle at high speed to stay running the carbs are in need of some service.
But it's not hard to do. Buy three carb kits and take your time. Once the carbs are done, and you have fresh gas and plugs, you have a good chance on it firing up. But you may then find it idling way to fast if you or the previous owner have adjusted the idle screw.
And if it doesn't idle you have covered the basics and go from there.

 

[oldboat1]

Did you make any progress? It's tough to do any mechanical work in a slip during boating season. There is usually a dock worker who might be able to help out -- and may be pretty good at diagnosing operating issues -- maybe can walk through starting procedures. He can probably also help get the boat to the ramp if you have to pull it. Don't be critical of anybody if you are the new guy -- but do try to get any specific info and history on your boat. PO still around?