Idle is waay too high. HELP!

[diggerdpilot]

Hi all,
I have a 175HP '88 Johnson. Runs great, normally. Last outing, a shift link bushing cracked, giving me fits that day. Replaced it, and upon starting it today, it goes almost immediately to around 25-2600RPM on startup, with no choke. It was always a bit coldblooded before. If I hold the key in and keep it choked, it will knock down to around 1600. I realize this is on muffs, but I cant get it down to the point to trying the gears, let alone stop gritting my teeth.

I recently blocked off the VRO system (oil alert-will run premix, just one less thing to break). I am running a bit rich pre mix now.

I have pulled the carb shroud, all intake butterflys are closed fully.
I have pulled the throttle linkage at the barrels, still races like this. Linkage is letting the carbs shut completely, even to the point of the stop off the block.
The solenoid lever is in the normal position, and since the choke will decrease the RPMs, I assume it is working.
I reconnected the plug that sounds the oil alert. No change.
I cannot find any evidence of an air leak in the intake system at all.

I considered the timing jumping, but seems kinda a long shot, plus, with the fuel at idle, figured it would run worse. It runs super high, but sounds good.

I would love some help on this one. I even went to the point of putting some duct tape on the hub to try to see if better backpressure would help. I have not put it in the ramp yet to see if water would do this, but I have doubts about it helping. Of course, this happened the night of the fireworks on the lake.

Welcome to boating, kids!

 

[jonesg]

Re: Idle is waay too high. HELP!

the timing is advanced, check that bushing on the linkage again, something is stopping the timing mechanism from retarding to the proper point.
You could try adjusting at the cable adjustment wheel, where it couples to the engine.

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

Hi Commander,

The bushing was on the shifter rod, the horizontal one that connects the lower unit rod to the cable shift. Hope that makes sense. We dropped the lower unit to change LU seals, and someone named my father forgot to put a small cotter pin back in, the bushing slid out to the starboard. No biggie, once I found it.

Havent checked the timing yet, I was actually leaning towards that, but am not the greatest timing expert. How does just advanced timing increase RPMs on the same fuel flow? Hope that doesnt sound too elementary. I did replace a couple magnets on the flywheel after a voltage reg. fire, and ended replacing the stator ring too, but for about 4 hours after putting it back in the water, it ran fine. Can timing jump like that after running good for a spell?

Thanks for the info, I appreciate it a TON!

 

[ezeke]

Re: Idle is waay too high. HELP!

He is talking about the timing advance, not resetting the timing. If the advance is forward and stuck for whatever reason you won't be able to get to a proper idle until you fix it.

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

Oh, I see.

OK, I am at your mercy. Do the 1988 quickstart motors advance the timing until it is hot enough at the block? If so, how do I troubleshoot or repair that? I wouldnt have thought the timing would unadjust, especially after running great after the stoddart ring and voltage reg replacement. I am happy at least my train of thought is comparable to you guys!

Thanks again-

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

PS, just to show my lack of knowledge, does the starboard side...bear with me here, not sure of the correct term.....the vertical lever that the throttle cable moves also control the timing advance? It is back all the way to the stop, as far as I know.

Thanks again, especially being the 4th weekend.

 

[jonesg]

Re: Idle is waay too high. HELP!

at idle fuel flow is metered, timing controls throttle until the butterfly's start to open, its something like the first 20% of throttle is controlled strictly by advancing the timing mechanism, then the butterfly's start to open and fuel flow transitions to the bigger jets.

Once idle mix is properly set then idle speed is adjusted by the advance mechanism. If you didn't mess with the idle mix then don't, its the ignition advance that needs adjusting. Try as I said with the throttle cable wheel.

Operate the throttle slowly in neutral and abserve the ignition advance, pull it back to idle and watch it, can you pull it back any further at the engine end, thats where it needs to be. You might have to disconnect the throttle cable to see the proper range, then re-fit the cable.

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

Will check.

Didnt know that about the timing controlling the idle rather than the fuel. See, I learn something everyday!

Dig

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

No good. Here is what I did, it might not be right.

Had the wife fire it from the seat, and had disconnetcted the cable from the throttle arm, the vertical one on the starboard side. I physically moved it to the slowest idle position I could, and had the stop screw almost to the rubber cap. It fired, at about 1800 RPM, then climbed back up to 2500. She killed it, and I refired again, this time holding it in place so there could be no drift. It ran at about 1800 for 4-5 seconds, then climbed right back up to 2500.

As far as I can see, the timing ring is back enough, it is almost stretching the wires on it. Is there another way to investigate the timing advance? Does the timing ring inside the stator physically advance when this works? I have been surfing this, and cannot fing the power pack wires (black/white) that control the quickstart system. It is a 1988 175HP Johnson, off the top of my head, a TLCCX model.

No idea what this could be. I even reconnected the VRO system in case some weird ghost was haunting it.

 

[diggerdpilot]

Re: Idle is waay too high. HELP!

Hey all,

I hate searching for posts, to find out they dont have an ending.
First, thanks to the helpers-much appreciated.

Second, it ended up being a slipped flywheel, just enough to shear the key, and advance the timing to the point of running that fast. Pulled it, replaced, re torqued, and ready to go. I think I mis torqued it when I replaced the voltage regulator.

Anyway, thank Neptune it was only a 50cent part!