J15RLCOB 15HP shuts off at idle throttle

[kbait]

Re: J15RLCOB 15HP shuts off at idle throttle

My motor has a similar prob, as the throttle just goes slower and slower till die when I take my hand off. I used a small c-clamp and a drop of grease and lightly pinch the throttle rod between the handle and the meshing-gear joint. It stays right where I leave it! Quick fix while you ponder..

 

[ondarvr]

Re: J15RLCOB 15HP shuts off at idle throttle

Here's a link to the prior thread on this subject.

http://forums.iboats.com/showthread.php?t=286066&highlight=throttle+adjustment+9.9

 

[Gizmobreaker]

Re: J15RLCOB 15HP shuts off at idle throttle

Bktheking, I think that you are saying that if I re-orient the bevel gear set at the very end of the throttle assembly (not at the pivot), I can more correctly sync the throttle with the Idle Adjustment Knob (and the icons on the throttle). I like that idea. I'll do that Saturday. Here's hoping that this won't lead to parts-in-the-water syndrome...

Ondarvr, I followed the thread that you suggested. It would appear that it is in agreement with what Bktheking is saying. That's what I will try next.

Kbait, the throttle stays put wherever I leave it, but since this is a sailboat, I cannot keep my hand on the throttle at all times. Wwhen I adjust to a slower speed, I want the motor to keep running and not stall. I want the full range of the tiller rotation to be between idle and WOT, without shutting the motor off.

The manuals are due to arrive Thursday. I'm keeping my fingers crossed. Sadly, iboats did not have any for my motor, so I bought from MarineEngines.com. Nice folks.

 

[Rick.]

Re: J15RLCOB 15HP shuts off at idle throttle

Please let us know how it all turns out. Rick.

 

[Gizmobreaker]

Re: J15RLCOB 15HP shuts off at idle throttle

The manuals have arrived. So has tropical storm Danny. I'm watching it rain on Saruday morning, as I type this.

Naturally, there does not seem to be a useful diagram of how to install the bevel gears at the far end of the throttle control. There is a photo showing that there are small dots or bumps on each gear for line-up. I can see how the gears go on the shaft and pin, but not where the pin goes, nor can I see any information on how the control shaft connects to the cam, but I guess this will be evident when I get to the motor.

If it ever stops raining...

 

[Rick.]

Re: J15RLCOB 15HP shuts off at idle throttle

Most of it will be obvious once you get started. The bevel gear that sits on the bottom of the cowl was difficult for me but I got the right procedure for Leroy Wisners site. There is a small nylon tube in the middle of the gear. Take a 1/4 lag bolt and turn it in there until it just grip and lift straight up and the tube will come up with the bolt. You might have to give it a shot of WD40 to loosen it first. Then the gear simply slides away from the other and then up and out. Best of luck. Rick.
http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm

 

[Gizmobreaker]

Re: J15RLCOB 15HP shuts off at idle throttle

I understand more, now. The bevel throttle gears (not the ones at the tiller pivot) are very sloppy. They seem to be correctly meshed. When the motor is not running, the lash is equal to half of the throttle movement. Luckily, when the motor is running, some of the lash is taken out by the natural tendency of the throttle to move slower rather than faster.

Right now, the motor runs about 800 - 900 rpm at the shift marks and I can get it down to about 600 rpm, but the slop in the throttle makes it very tricky. The Idle Adjuster is all the way in. I can see how a small block added to the end of the adjuster would help, but I think that the lash is the real source of the problem, so I'm going to attack that, first.

I will be ordering parts.

Thanks, everyone, for helping out with this. It's been driving me crazy for some time.

By the way, I would not order the parts manual when buying the service manual. All the images are readily available on-line. Nice to have, but not really worth $28.00.

 

[Gizmobreaker]

Re: J15RLCOB 15HP shuts off at idle throttle

OK, now I am really confused. Apparently, all of your suggestions were correct. I have not installed any new parts. I have the Idle Adjustment Knob set at maximum.

For the past 2 weekends the motor has been a beast. Starts first pull. Runs strong. Does NOT shut off at minimum throttle. Yesterday, it moved my Catalina 27 at 6.2 knots, by GPS, at less than full throttle. I think that is max hull speed. Previous best was just over 5 knots.

Thank you, everyone, for all the great help.

Now, if you could just figure out how the rodents are getting into my crawlspace...

 

[Rick.]

Re: J15RLCOB 15HP shuts off at idle throttle

In the middle of the bevel gear that faces up is a small plastic tube. Take a 1/4 inch lag bolt and thread it into the center by hand just until it grabs. Then pull it straight up and the tube should come out with it. Then you simply slide the gear off to the side and up. Best of luck. Rick.