BX25 Engine Problem

[kb9okb]

I've had my used BX25 (500hrs.) for a few weeks now, but it's having itermittent engine issues. After running it for a few minutes, sometimes the RPM drops to <1000rpm and stays there. Sometimes it dies, it will always restart but still won't exceed 1000rpms. Throttle linkage is working fine. Air filter looks good, I'm wondering if it's not a fuel filter issue, I'm checking that now. Any ideas? Fuel pump? How can I test that? Things I should check? Thanks in advance!

 

[Mystro]

Clogged fuel filer. I think there is two.

 

[pdowling1]

That sounds right, the one closest to the tank will be the problem, the 2nd one rarely has issues. I hear it is there just in case the fuel pump self destructs.

 

[AStanton]

There are two fuel filters: one near the engine, one under the tractor. Because there are no shut offs for the fuel line, I did this trick when I swapped out my filters. Remove the fuel cap, then place a piece of plastic wrap, like Glad Wrap, over the fuel tank opening. Then put the fuel cap back on, threading it over the plastic wrap. The plastic wrap prevents air from venting through the cap. (Plumbing 101: Air moves liquid.) Using this method, I only lost about a half pint of diesel.
Good Luck.

 

[pdowling1]

You can also clamp ViseGrip pliers on the line(not too tight) to block fuel flow while changing the filter

 

[kb9okb]

Where is the rear fuel filter? Does the mid mount mower have to come off? If so that could be a problem as I have no hydro power.

 

[radioman]

look underneath the tractor on the FEL control stick side. you could do it with MMM on but it could be frustrating that way. taking the MMM off and on is not that big of a deal. I take mine off more times in course of year then I can count my fingers.

 

[kb9okb]

Well crap.. now it won't run at all, and the Mower deck is locked in the top position so I cant even look for the filter.

 

[BotaBigot]

Jack/block deck enough to relieve weight so you can turn height knob...as for no run, in addition to filters/pump, check for fuel contamination...i.e water...

 

[GolfAddict]

Jack/block deck enough to relieve weight so you can turn height knob...as for no run, in addition to filters/pump, check for fuel contamination...i.e water...

I think you are going to want to try what BotaBigot suggests to get the MMM off. The two filters are kind of a pain to change. I can't imagine trying to do the one underneath with the MMM on. The second one, up on the side of the engine, could be done without removing the MMM, although it's also a PIA to change unless you take the engine shroud off.

Here is a good "how to" thread on changing the two filters on a BX24 (which I believe is the same for your BX25.)
http://www.tractorbynet.com/forums/kubota-owning-operating/147385-bx-fuel-filter-change-lessons.html

 

[kb9okb]

Okay thanks everyone, unfortunately I still was not able to get the MMM to drop without power. I ended up calling the Kubota dealer, who sent someone out ($85/hr) and it looks like he got it taken care of. I watched the tech do his thing via surveillance camera... looks like he had to fight with it for a while before he got the MMM to lower. Once he got that, he replaced the lower fuel filter, and it appeared to run fine after that. Hopefully there isn't anything in the tank (from the previous owner) that will cause the problem to recur.

 

[AStanton]

Glad it worked out. I find that as I age, I'm thankful for any problem that can be solved by time and a little money.

 

[Mystro]

X2.....

Glad it worked out. I find that as I age, I'm thanked for any problem that can be solved by time and a little money.

 

[kb9okb]

Update on this topic... just had my fuel filter clog AGAIN. This time, fortunately, I was able to react quick enough and get the deck lowered and off while I still had some power. I was able to remove the fuel filter easily and got a new one at a local Orelly's auto parts, and replaced it... runs great again. So, to find out what has been causing this (twice) I cut open the old fuel filter and found a chunk of nearly solid red-brown sludge (about the size of a pea) actually in the intake port of the filter (not even touching the filter portion itself. The rest of the filter actually looks okay. Anyone know exactly what this might be? Also, after the last incident I purchased some BIOBOR and added it to the tank- not sure if it's helping or maybe even hastened the sludge loosening / gathering in the filter.

 

[Tractor Seabee]

Join the BX club. I had the same problem at about 400 Hrs, no MMM but had to tow to the shop as did not want to crawl in the mud. Mine had black gunk in it, clogged till it would not even leak fuel when the outlet hose disconnected. I have a needle nose vise grip that works great for pinching off hose. At the 400 hr service I moved the engine side filter down under along side the other one. I have a filter wrench to remove the oil filter w/o removing the cowling as the manual says. That cowling is a real PIA to take off and on. Over 500 hrs now and no more problems with that. I think QA at the factory is poor during assembly hence the debris in closed components. Had a similar problem with the hyd system with debris in the strainer at the 50 hr service. I am considering addng a valve in the fuel line coming from the tank tghough. That would be a deterent to theft also. They would not drive very far and probably not think about looking under there.

Ron

 

[radioman]

well -- look at it this way. you are doing the right thing now. Adding BIOBOR JF should be killing off whatever bugs you got in the system, but you gotta remember something. Anything you kill off, leaves behind a "body" so to speak. You might be replacing that filter several times before you get a clean tank/lines. Just remember to always treat your fuel now with every fill up. Did you get the test kit from BIOBOR to see if you truly have bugs in your system or might be dirt that got in your tank ?

 

[dodge man]

I've had mine clog up twice, both times the filter didn't look that bad when I cut it open. They are kind of a small filter for a diesel in my opinion.