Quicksilver generator hunting

wileecoyote

wileecoyote

Member
TECHNICAL Contributor
Oct 18, 2008
949
Southern MD/ Potomac river
Boat Info
1989 340 EC
Engines
7.4LX2 Hurth 630A Drives
6.5Kw QS Genny
OK, Last year Generator seemed to run fine for the 5 min I heard it run. When I got it in the water the generator would hunt, idle up and down. I replaced cap, rotor, wires, and plugs. Didn't do the points and condensor. Changed the canister fuel filter. Changed Oil and filter. Started it up and ran for about 5 minutes and it shut off. Checked for water from the side, because it felt hot to me, no water flow. Now, PO wanted to show me it worked, but forgot to open seacock. I had guessed it was already bad. Replaced the impeller, cam, and backflushed the heat exchanger. After I changed the oil, I pulled the plug in the back of the govenor and filled from the top until it came out of rear plug. Measured rod length and it is the 4 3/8 it is supposed to be. Now start it and have plenty of water flow, charges and runs A/C and everything on panel, but.... Still runs up and down up and down. You can steady it just by holding rod and getting sweet spot, but as soon as you let go, 10 secs later up and down. Whats next??? Carb rebuild?
 
A few questions:

1) How many hours do you have on the generator?
2) Did the rpms flucuate for the previous owner?
3) Does it flucuate the same under a heavy load?

-John
 
Try tightening nuts on Carb, Had same problem and finally found vaccum leak on carb mounting. It is hard to hear hissing when work on carb. Some one standing over me heard it a suggested a vac. leak

Picasso
 
PlayDate said:
A few questions:

1) How many hours do you have on the generator?
2) Did the rpms flucuate for the previous owner?
3) Does it flucuate the same under a heavy load?

-John
Click to expand...
1) 800-900 I can't remember the exact number right now
2) I do not know, Looking at the survey he had done he ran it less than 2 hours in the 10 years he had the boat.
3) Yes. Runs the same under load. I can still load it and run A/C and all the acc. It works, just hunts up and down.
 
Hmmm.......

Let's start with the governor. That model has a mechanical governor driven by a belt. Check the belt to ensure that it is in good shape and not slipping. The infrequent use causes the belt (and a lot of other parts to have issues).

There was a thread .....a couple of years ago where the end result to a similiar problem required replacing the governor.

It would also be helpful to run a compression test on the cylinders to ensure that they are good working order.

Let's start with the belt (condition/tension) and a compression test and go from there.

When you pull the plugs for the compression test, take note of the firing electrode and note whether they are black/white or tan.

-John
 
John, plugs are brand new, the old ones when I pulled them looked to me like #1 was a bit rich. I will check the belt later today. I haven't done anything to the carb and didn't do compression check. When the PO started it last year(and burned up the impeller) it ran just fine.
 
John, Belt was a bit loose. I tightened it and checked that it wouldn't slip while running. Started and up and down it goes. Loaded it and steadied idle, which lasted about 8-10 secs. Carb is tight. When idle is held steady engine runs great, no up or down, no misfire. Will have to check compression later when I get a chance. I'm thinking something is wrong in the governor, even when idle is held steady it seems governor is trying to move back and forth? This is why I checked oil level, I thought maybe it was needed to stabilize it some.
 
wileecoyote said:
John, Belt was a bit loose. I tightened it and checked that it wouldn't slip while running. Started and up and down it goes. Loaded it and steadied idle, which lasted about 8-10 secs. Carb is tight. When idle is held steady engine runs great, no up or down, no misfire. Will have to check compression later when I get a chance. I'm thinking something is wrong in the governor, even when idle is held steady it seems governor is trying to move back and forth? This is why I checked oil level, I thought maybe it was needed to stabilize it some.
Click to expand...

I just looked at the service manual for your unit. Unfortunately, there is not a rebuild process for the mechanical governor other than removing the alternator portion from the front of it. Since it runs smooth when you are holding the linkage, there appears to be an internal issue with the governor itself. The governor has an internal spring and flywheel which work in conjuction with each other to stabilize RPMs.

If it wasn't running smooth as you held the linkage.....we would be looking somewhere else (compression, fuel, electrical....). You probably will have to hunt around for the part. I will check my previous posts on this and see where the last owner found a replacement part. Quicksilver were Generac units.

-John
 
Last edited:
I PM'd Mike, but never got a reply. I wanted to see if the governor was a long term fix or not. Before I order the $230 part, what else besides comp check should I do? If I remember, when I get home, I will make a video of it running so you can see what I am talking about. Then I will send you a link. It will be hard to tell, but better than my explaination I'm sure!
 
Hopefully, Mike will respond. Generators can be problematic. I'm actually surprised that someone still has parts for these units. $230 is better than I thought it would be.

I look forward to the video.

-John
 
It appears as though it could be governor could be the issue. I would pull the carb apart and inspect/clean it just to be sure. It's quite possible some small debris has made it's way in there causing the engine to hunt.

Doug
 
Ordered the governor, spring, belt, and fuel filter. Got an email Sat that there was a problem. The spring isn't $17.80 anymore. It's $79.25:wow: Told them keep the F*$#ing spring! I will do the other stuff first and continue to look for a 64Lb spring. For that price I can get one custom made, if need be. Anyhow, this weekend we anchored out and I wanted to run it, so I started it, loaded it up with what I wanted on, and stabalized the idle and clipped the vise grips on the governor arm. Ran it for 6 hours and it worked like a charm. Not ideal, but made sure everything that was going to be on was on when I did it. About froze the dinette/galley area, because I set the A/C all the way down, so it wouldn't cycle!
 
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