Help with idle adjustment

[iggyw1]

I have a 70 H.P. Johnson motor I believe is a 1984 model (??) and it has two year old controls cables for the throttle and the gears. The control box is next to the driver and goes back to the motor. The model number for the motor is: J70ELCNB. I have the lever on the controls that you raise up a bit for faster idle when starting the cold engine, then you push the lever down when it is warmed up a bit. Key pushes in for the choke.

Here is my problem: When I push the lever down, the throttle does not cut back all the way. Same as when I put her into gear and give it some gas. I pull back on the throttle and the idle is way too fast still. It will goes down to about 1300 RPMs and no lower. I can go to the motor with the cover off and push the throttle back by hand to idle at 700 RPMs, but I cannot keep doing this all of the time!.

I tried to adjust the cable by turning the adjustment wheel at the motor that is on the cable. I adjusted it both ways, forward and backwards. As I turned it towards the back of the engine, I noticed it lowered the idle, so now it is turned towards the back as far as it will go, but I still have to push the throttle back manually at the engine to lower the RPMs. The cable for the throttle is not that old. Could it be a bad cable or is it just an adjustment? It does not seem that I can adjust it any farther as I am at the end of the threads on the cable. What can I try next? I took the remote box apart, and there does not seem to be any adjustment for the cable at that end. Any ideas? Maybe WD-40 all the linkage on the throttle and carb and stuff on the motor? Thanks for any help you can give me.

 

[flyingscott]

Is this happening while it is on muffs?

 

[iggyw1]

Is this happening while it is on muffs?

Yes it is. I will be going to the lake and taking it out for a good spin tomorrow. The boat was last ran in the fall of 2016. Was not used at all last year in 2017, and it was under shrink wrap here in Mich from Nov. of 2016 until just the other day. It started right up with some fresh gas & oil added and runs perfect except the darn idle is too fast when cutting back on it. When we parked it, it did not do this.

Getting back to your reply to me, (thanks by the way) does it make a differance if it is on the muffs or in the water for this idle problem?

 

[oldboat1]

Think the idle on muffs is something like 1100-1300 rpm, 700-750 in the water (back pressure).

The slop you seem to have with the throttle linkage sounds like it's a problem. On the smaller '82s, the cable clamps to the motor housing with a plastic device that captures the adjustment wheel -- kind of ingenious. I'm not sure how yours is secured to the pan, but if the cable is floating loose that would be a problem.

 

[flyingscott]

Your motor will idle higher on muffs because they cause a lean conditon. That is why you HAVE to set idle on the lake ,in gear and at operating temp. The throttle cable slop is built in to the controller. The reason is you cannot have the throttle moving at the same as you are shifting. Your in gear idle speed will be around 750 rpm and neutral idle be about 1000 rpm. The important speed is in gear.

 

[iggyw1]

Thanks guys. When it is idling at the fast speed, it is not "banging" into gear. It goes into forward & reverse real smooth. I will see if there is definately a difference when I take it out on the lake. I hope it is O.K. Just never noticed the high speed of the idle before on the muffs. I was gonna do that tomorrow, however, our nicer day here in Mich will be on Sunday (60 degrees)! Tomorrow I will be vaccuming the boat and washing the windshield and Armorall the seats and dash board and such. Boat needs a good cleaning before I sell her.

I sold it to a good friend of mine in the fall of 2016 and he was gonna sell an old 1965 T-bird sitting in his garage and pay me out of the proceeds from that sale. He ended up dying, and I never got paid. His family had the boat shrink wrapped before that winter, and it sat there until they gave me the boat back about a week ago. They knew he did not pay for it, but there was a problem earlier with the sec. of state as his next of kin (his mom) was living in California, and we did not have a birth cert from her until she moved here this year into my buddies old house.

I will let you guys know my findings when I do end up taking it out on the lake Sunday. Thanks!!!

 

[iggyw1]

Think the idle on muffs is something like 1100-1300 rpm, 700-750 in the water (back pressure).

The slop you seem to have with the throttle linkage sounds like it's a problem. On the smaller '82s, the cable clamps to the motor housing with a plastic device that captures the adjustment wheel -- kind of ingenious. I'm not sure how yours is secured to the pan, but if the cable is floating loose that would be a problem.

This motor may be a 1982 model, I am not sure of the year. Has low hours and real good running. (except the idle does not cut back like I expected it to). The throttle cable is secured to a block in the motor housing. It is not just loose in there. The gear cable is right next to it and secured to the same block, and they both have an adjustment wheel on the cable. I am at the end of the adjustment for the throttle cable. The gear cable I am not touching. It is perfect where it is! But yes, they are both secure and no slop at all under the motor hood.

 

[flyingscott]

YOU CANNOT adjust idle on muffs!!! Of course it shifts smooth there is no resistance to the prop in air. Get it in the water and make your adjustments there after the motor is warm.

 

[iggyw1]

YOU CANNOT adjust idle on muffs!!! Of course it shifts smooth there is no resistance to the prop in air. Get it in the water and make your adjustments there after the motor is warm.

That's what I will do. I am going out on the lake on Sunday and I will make my adjustments out there while the motor is in gear after the motor is good and warmed up. I plane on going out there and giving her a good work out because I want to make sure it is running great before I sell it.

And what I meant by shifting smooth is that it is not banging into gear from the speed of the idle. I know I had a boat before that every time I put her into gear, it would bang into gear until I had the idle turned down and that was on muffs and in the water. Try putting one into gear even on muffs at 2000 RPMs and I bet it will bang even with no resistance from air. I am just trying to clarify what I meant by it is not banging into gear. Thanks again for your help! I will let ypu know after I go out on the lake how much the RPMs came down on the water.

 

[iggyw1]

UPDATE on my idling problem: On the muffs in my driveway, my motor would only go down to about 1,200 on the idle. The guys that replied said to adjust the idle on the lake, which I did today (finally). I went to the lake and started her right up, and after it warmed up just a few short moments, the idle went down to 750-800 RPMs. Ran perfect! Thank you guys you were a great help to me (as always). What a great forum for us that have motor problems. THANK YOU !!!!!!!!!!!! I can go ahead and sell the boat, motor & trailer now with no worries that someone will be having a problem with the idle on the motor.