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JD JX75 running rough

#1

Keith5486

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.


#2

S

slomo

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

slomo


#3

Scrubcadet10

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.


#4

Keith5486

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.


#5

Keith5486

Keith5486

Engine is a FC150V-HS00


#6

S

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


#7

Keith5486

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.


#8

S

slomo

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

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#9

S

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? o_O

slomo


#10

Keith5486

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.


#11

S

slomo

Might be the audio on the video. Sure sounds like a ton of revs at my house. Maybe the camera messing with the revs??

slomo


#12

Keith5486

Keith5486

It sounds fast. I agree. But also sounds like a rattle too. Something seems off balance. I'll look over those pages again tomorrow. As I said. I got the governor done and ran out of light.


#13

Keith5486

Keith5486

This is my seemingly well running 14sb



#14

S

slomo

Just watched the video again. To me, that brings back memories. Of using Honda push mowers and having to run a bungee cord on the carb linkage to cut grass. We ran them WFO the engines were so gutless.

slomo


#15

S

slomo

This is my seemingly well running 14sb

THAT sounds like 3k.

slomo


#16

Keith5486

Keith5486

Lol. Hopefully that's not the case. I'll get back tomorrow after further adjustment. The manual says to warm up engine before adjusting fast idle. How do I warm up the engine without it blowing up at 10262926k rpm its currently running


#17

S

slomo

They both have an infrequent slight sputter. The top engine might be sucking the carb bowl dry LOL with all the revs. :)

slomo


#18

S

slomo

Lol. Hopefully that's not the case. I'll get back tomorrow after further adjustment. The manual says to warm up engine before adjusting fast idle. How do I warm up the engine without it blowing up at 10262926k rpm its currently running
You have a throttle lever on the handlebar. Pull the sucker back about 3 feet LOL. You are about the stretch the rod, in a bad way.

Like I mentioned, follow the directions exactly. Read them a couple of times.

slomo


#19

Keith5486

Keith5486

You have a throttle lever on the handlebar. Pull the sucker back about 3 feet LOL. You are about the stretch the rod, in a bad way.

slomo
Whatcha mean stretch the rod?


#20

S

slomo

Whatcha mean stretch the rod?
When the rod, lets go from over revs........

slomo


#21

Keith5486

Keith5486

Gotcha. Gunna try to avoid that. I'll try get her slow down. Warm up and adjust everything. I'll touch base with yall tomorrow. Thx for the help.


#22

B

Born2Mow

Someone suggested the fuel filter may be the problem....doubt it but ill take it out of the equation.
BAD idea !

Remove the filter and blow compressed air through it in REVERSE direction if you want to unclog it, but most definitely re-install the filter.


#23

Keith5486

Keith5486

BAD idea !

Remove the filter and blow compressed air through it in REVERSE direction if you want to unclog it, but most definitely re-install the filter.
Line is clear. I've already verified it was clean and the tank did not have debris in it either.


#24

S

slomo

As mentioned, keep the filter in play and a good shutoff valve while you are at it. Run fuel stabilizer year round. Never have a carb issue again.

slomo


#25

Keith5486

Keith5486

Ok. Updates. I've played with the throttle cable adjustment for about and hour without luck. I follow the institutions. Go to remove the pin as it states and push forward to choke position the lever doesn't move. I can manually move it forward but the handle lever/mechanism doesn't move it. Ill work on a video


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