B8200 Knock from intake

[dusty-t]

My son was going to take the kubota out to do some tilling and he heard strange noise from engine. Pull the hose off of the intake and you hear a loud thumping, rev it up and you hear a thump and a knock. If anyone can understand my noise terminology. Any help would be gratefully received.

 

[dusty-t]

Decompressor??

 

[eserv]

Something is wrong with a valve. either decompressor is stuck on or valve stuck possibly a bent pushrod you don't use starting fluid do you?
Ed

 

[dusty-t]

Nope no starter fluid. I have never needed it with this tractor.I don't like using it anyway. This tractor has no block heater and would start at -20 no problem on the glow plugs. I had it running yesterday and no noise. I will pull the head cover in the morning. I hope it is the decompressor. I can move the decompressor lever on the engine by hand and it springs back but not all the way.

 

[dusty-t]

Something is just not right here. Any thoughts comments. HELP

 

[Jlillie]

Something is just not right here. Any thoughts comments. HELP

Yikes, that doesn't look good...
Is the valve spring on the other side weak? (Or broke?)

 

[dusty-t]

I almost blew it. I should have done a bit more checking before I put it back together. I should have asked myself why was that rocker so loose.Any way I set the rockers and started it up and it ran fine. Long story short, the rocker shaft hold downs were loose. Re tightened everything and it runs good. Now I will pull it apart and see how bad everything is worn.

 

[joekimtkd]

How could it be possible? Any how, you found the trouble just like that... Wow...
I'm envy you...! Is your cab done yet? Where did you get your paint? Home Hardware's Kubota orange paint wasn't good at all. so I had to return it. Now I have to looking for that Kubota Orange paint some where...

 

[dusty-t]

Hi joe , well finding it and fixing it might be two different stories. But all in all it could have been a lot worse. I got orange spray paint at home hardware and it worked allright but they only had one can. I got the rest at canadian tire the only thing is it has a really long drying time. It is really cheap though, like $4.50 a can. It is part# 048-9180-4 but get it in Hanover I cleaned out the Mount Forest store.

 

[RDR]

Before I noticed the pushrod out of place I noticed how dirty the engine looks. Glad you figured out the problem. Looks like you need to change your oil more often or change brands of oil. It looks like the old engines that only had non-detergent oil.

 

[dusty-t]

Oh it needed an oil change for sure. But thats not oil thats tranifluid.I was just flushing the engine. That was some nasty oil that came out.I pulled the rocker shaft off and pulled the rods and everything looks amazingly good. Its going back together. We will see what it does. I need torque specs for the head bolts, those rocker shaft hold down nuts and the head cover nuts. So if anyone could supply that info it would much appreciated. And yeah it wasn't so much my eye's as being in a hurry to get it back inside before I got rained on. My eye's were not looking down as much as up. I have some time but very little cash is there anything else I should be checking to avoid disaster. When I put it together it ran real good , no odd noises or anything. I didn't rev it out or anything cause it's got trani fluid in the crankcase and the head cover isn't on it,but like I said it ran fine. If I am missing something please let me know. A diesel tech I am not. Thanks for the replies guys.

 

[joekimtkd]

Ha ha ha... you cleaned up the Mount Forest store, Huh~?!
Is it very close to Kubota Orange color? Could it be possibly scratch free?

 

[eserv]

You guys know that there are two Kubota Orange colours right? The new one is called Bright Orange the old one simply Orange The older Kubota's will have the simple orange paint. ALL Kubota colours fade badly if left in the sun so matching paint is a real challenge! LOL
Yes Joe, Stu would be considered an older gentleman probably pushing 70 or maybe more. they live just east of Durham and north.
Ed Service

 

[dusty-t]

Yep I know there are two colours of kubo orange. I had two cans of kubo orange when I started painting the cab. The first can was the new orange which was what I wanted. The second was the old orange. Yup made a mess I did. Anyway thats when I went and got the other paint. And no Joe it is not scratch free or dust free or run free. Now on to the problem with my engine. My worry is this. On another thread they were discussing valve lash and how too much play can harm the valves and the valve seats. I already Know the answer to this but I am looking for any kind of false hope I can come by. The tractor has smoked since the day I got it. Now I know why.The engine has never been really noisy but the smoke says the rockers have been loose for a long time. I can only hope that Kubota's valve train's are really really really really tough. It is going back together tommorow so cross your fingers for me.And yes I am still smiling this isn't even a bump in the road of life.

 

[dusty-t]

It is together it runs, it runs good. I will leave it at that. I will keep my ears open for any increase in noise. I will probably have the rocker cover off a couple of times over the next two weeks.Wish me luck and thanks for the responses.

 

[eserv]

I wouldn't wear out the bolts taking that cover on and off, if it's running good now I'm sure you won't have any problems in there. Loose valves are better than tight valves as far as doing damage. Too tight valves don't cool well because they don't contact the seats securely enough or maybe don't contact at all. valves are cooled partly by contact with the relatively cooler valve seat.
Ed

 

[dusty-t]

Thanks for the reply Ed. I put locktite on the nuts on the rocker shaft hold downs. So I'm not really worried about those, but I just want make sure that the valves stay the same as when I set them. Finger tight and and back off a quarter turn. I didn't have any specs so I just played it by ear (literally). Probably about 20 thou play with valve closed. And I disabled the decompressor.

 

[handyman]

Dusty good luck hope you dont hear any louder noises or have to pull cover again.I saw same picture of push rod on a few gas engines in my time. But when it your own its O HECK time.handyman

 

[handyman]

Dusty I apologyize in advance and I am new.But when you adjust those locknuts tight and hold the top with a screwdriver the locknut usually dont back off unless the cam is not in the correct position for adjusting clearence am I right or wrong? I apologize again but I may be in left field. Your cab looks good bet it will be warm in canada this winter in it.

 

[ipz2222]

Dusty , that pushrod came out of position because it was loose. Causes are, loose adjuster, tips worn on rod or rocker arm and the worse, cam lobe. If you can, pull the lifter out and look at the bottom of it for wear. You may need a cam.
Another way to ck would be to use a dial indicator on each rocker arm to measure all cam highths and compare. Most people don't own a dial indicator unfortunantly.