JD JX75 running rough

[Keith5486]

Got this mower as part of a bundle. Best looking of the group. Changed oil. New carb. Fired up but runs rough. Smooths out a bit with the BBC engaged. What do yall think. Any guidance would be much appreciated.

 

[slomo]

Revs are way too high. Needs an air filter ASAP.

slomo

 

[Scrubcadet10]

Yep, get an airfilter, should be this one https://www.amazon.com/John-Deere-Original-Equipment-M79451/dp/B01FC8BLZC
Not sure of the engine, but i think its a Kawasaki FJ180
. You may need to adjust the governor also.

 

[Keith5486]

Even with an air filter she still runs fast. I'll try adjusting the governor and throttle plates in the next couple days. Someone suggested the fuel filter may be the problem....doubt it but ill take it out of the equation. I did change the gas gap from the orange one in the video to a black vented one thats on my working 14sb. That smoothed it out a bit but still running fast.

 

[Keith5486]

Engine is a FC150V-HS00

 

[slomo]

OEM Kawasaki carb or Chinese Ebay Kenny Rogers Gambler series?

I'd get a tiny tach and cut the revs in half LOL. Idle speed is 1850rpm and full zip either 3400 or 3600rpm. I have one of those engines. That little guy drinks some gas for a small 145cc engine. Funny how my larger 190cc engines suck less fuel per mowing.

I would adjust the valves too. I hope this hasn't been ran its entire life in NASCAR mode.

Check to see if the blade is out of balance. And if the bevel is not straight like someone used a grinder to sharpen the blade. If so it most likely is out of balance. Scrape the under deck area.

Remove the top engine cover. Clean the ENTIRE cylinder block cooling fins. Check for grass, oil, dirt, grease, grime and grit in the fins. Check the bottom side with a mirror.

Clean plug or replace with OEM NGK.

I would say the fuel filter is not the issue. You get some nice revs out of her. Probably a bad carb. There is a pilot screw on that carb. Course at those revs it's definitely on the main jet most of the time.

slomo

 

[Keith5486]

So my working 14sb idles at 3k rpm when under load it holds about the same. The JX75 is only slightly higher. Like 3200 to 3300. It just vibrates like it's unbalanced. I adjusted the governor per spec but ran out of light to just the idle speed. Ill try that tomorrow.

 

[slomo]

These are for the FC150V. Check these out word for word on your engine.

 

[slomo]

So my working 14sb idles at 3k rpm when under load it holds about the same. The JX75 is only slightly higher. Like 3200 to 3300. It just vibrates like it's unbalanced. I adjusted the governor per spec but ran out of light to just the idle speed. Ill try that tomorrow.

Brother, that engine sounds way over 3300rpm LOL. Is your tach on 2 stroke mode?

slomo

 

[Keith5486]

It's a cheap tach that just wraps around the spark plug wire. Ill double check again tomorrow. Used it just the same on my well running 14sb and showed 3k. Ill post a link of that. Stand by.