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JD 345 Engine Surge & Charging Issue?

10K views 11 replies 7 participants last post by  denverguy 
#1 · (Edited)
Hello,

I recently purchased a 1997 JD345 with the 18hp Kawasaki FD590V. I was told the "plastic" cam gear was replaced when the engine was overhauled (when unknown) & the carb was replaced before I purchased it as it sat for a while and the old one was gunked up. The hours meter shows 2,200, but the guy I bought it from thought someone left the ignition on and ran it up. It's in decent shape overall so who knows.

Anyway. The tractor ran great when I bought it but I've been having some issues since. I started experiencing engine surge halfway through my first mow, which was in 90 degree heat and mowing some pretty tall grass/weeds, don't think it overheated though... This surge typically does NOT occur at full throttle, sometimes when not moving, but almost never while in motion or with the deck engaged (runs better with a load on the engine).

I did some regular maintenance items (fuel filter, air filter, spark plugs and a plug cap) in hopes it would correct the issue, but it continues. I sprayed some carb cleaner down the carb while running it a bit and it did seem to reduce the surge issue during that run. I am getting spark in both cylinders. Throttle/governor linkage/springs look to be in working order. It is tough to engage the choke (push throttle past full position style) and noticed the throttle cable has some tape on it towards the throttle lever. I am running 89 octane w/o ethanol and put stabil in fuel b/c I'm only using this to mow every other week or so.

Additionally my battery light started to turn on, and typically more so when at lower throttle. I tested the battery and it's fine. I did a quick mow around the pond this morning and both issues persist, started kinda rough and wanted to die with the throttle below 2nd from the top position.. Rain chased me off from attempting any additional troubleshooting.

I've read the battery light indicates a charging issue (not battery) so I know I need to check the voltage regulator next, ~14.5V? Could these issues be related? I'm open to suggestions on what to do next regarding the engine surge. Could the carb jets be gummed up already? Related to throttle cable? Valve adjustment? Vacuum leak?


Thanks,
Kurt
 
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#2 ·
The throttle cable could've slipped on it's clamp.Pull off the hood and see if the cable moved.There should be a wear mark where it was clamped down.If not loose the cable clamp and move it to see if it corrects the problem.
 
#4 ·
Definitely sounds like you have 2 separate problems.
Running issue & charging problem. Don't think the 2 are related.
Definitely check the voltage at the battery with a meter. Do idle speed and fuel throttle.
 
#5 ·
With a known to be good battery, fully charged, engine not running, voltage should be 12-12.5 V, typically. Start the engine and check the voltage at the battery at different throttle settings. Should max out at about 14.5V. Also try turning the headlights on and note any changes. If you aren't seeing a normal charge routine, shut it off, disconnect and clean both battery cables at each end. I don't know where the regulator is mounted on this one but normally it's hidden behind something near the dash support. Unplug the connection (with battery cable off) and look for corrosion and or melted plastic connector. Sometimes, a poor connection there is the problem. Getting a solid clean connection there may be all you need to get back to charging properly.
There is a big bundle of wire connections down on the left side of the engine that could get corrosion and overheat. Check that out too if the problem still exists.

As for the surging, most often the carb. has to be removed, completely disassembled, and thoroughly cleaned and blown out with air. There are several small jets, some stacked on top of each other that need to be taken out to accomplish this. Properly sized screw drivers and great care removing and replacing them is highly recommended. 'tain't rocket science, but ya gotta be diligent and determined. You may never find the small speck of junk causing the problem, but it's there.
Also make sure to examine the inlet nipple for any debris in there. You should be able to blow through it when clean. The hole at the end of that nipple is usually much smaller than the outside hole. A tiny piece of rubber from the fuel pump or fuel line sometimes floats around in there and creates a different symptom - randomly stalling the engine while in use. Sometimes starts right back up. Not your problem now, just a heads up for the future.

tommyhawk

P.S.

This is not a 345 but you probably have a similar wire bundle on the left side. These get disturbed or disconnected when removing the engine.

Wire Electrical wiring Cable Electrical supply Technology
 
#7 ·
Thanks all for the input. What about a vacuum leak? Does anyone know the best way to test vacuum pressure on this machine? What is the range I should expect? I've heard I can test off of the vacuum hose going into the fuel pump?
To test for a vacuum leak. Start engine and allow it to idle. Spray a little carb cleaner around the outside of the carb and intake manifold. Do all the way up to the heads. If it is sucking in extra air it will pull the cleaner into the leak. This will either raise the engine speed if what you use is flammable. The engine will stumble and or stall if using an inflammable spray.

Be careful not to let the spray get sucked into the carb opening. This will give you a false positive. Also be careful not to start a fire.

You can't use the port for the fuel pump. It's not connected to the intake. It is connected to the crankcase. The up & down motion of the piston creates a pulse that works the pump. Piston going up creates a vacuum. Piston going down creates a pressure.

If your carb or intake manifold has a vacuum port you can attach a gauge to it. However most small engines do not have one.
 
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#10 ·
A loose governor as mentioned is a real possibility. If it is loose you need to reset the governor. Loosen the governor set screw ensure that the throttle is wide open and rotate the governor in the direction of the throttle. On my 325 that would be counter clockwise as the throttle moves up. Make sure to take several pictures of the whole assembly before you disassemble. Also not that the main throttle plate has one fixed screw on the left and one on the right that is adjustable up and down. Mark this spot before you take apart. This is the set up on my 325 and may differ for you, but pictures can be a huge help.
If not the governor I had a surging issue which turned out to be a torn intake casket.
As mentioned a good carb clean is probably in order. Welding tip cleaners can be very useful in opening plugged openings.
 
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#11 ·
Not to hijack this post but I have same issue with battery charge light on all the time. Battery is 2 months old, problem just started, volt check is good 13.2 not running, 14.75 wide open throttle around 14 idling. This tells me Voltage REGULATOR is doing its job. Checked all connections I could without removing the vr. Any thoughts would help. Will it hurt to just run the mower with light on? I have a post on my issue but did all that was suggested, help.
 
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