i have a problem with my timber harvester mill

gary · March 08, 2006, 07:56:39 PM

When i am cutting the mill has to move at its slowest speed or the engine dies. It will idle just fine . The only time I have problems is when the blade is in a log. I called the company and the sevice tech said it might be the injection timing. Can anyone explain what injection timing is?

logwalker · March 08, 2006, 08:28:16 PM

Are you running that 28 hp Kohler? He is refering to the point in the rotation of the engine where it injects the fuel into the intake to be followed by a spark from the coil to cause a power stroke. It doesn't make sense to me but then I don't know how they are mapping their injection timing curve. Ask him to explain some of the causes and fixes and get back to us.

dutchman · March 08, 2006, 10:28:55 PM

Need more info:
What motor are you running?
How many hrs on it?
Does this happen everytime, or after engine is warm?

You say you get into the log , so you must be getting high rpms.
If it stalls or idles down under load, I would think valves might need adjusted.
Best guess.

Rancher · March 09, 2006, 12:09:43 AM

I wish your problem could be as simple as mine was the other day. I had a similar problem. All ran fine...until I tried to cut. Finally, I couldn't even go slow enough to keep the band from stopping. Then I remembered KISS( keep it simple stupid ). Amazing what a little bit of air did for the air filter, until I can get a new one.

Dave

gary · March 09, 2006, 06:07:04 AM

The saw was made in1996. It doesn't have an hour meter on it so I don't know how many hours are on it. It has the 21.5 deutz deisel engine on it. This happens all the time .

Minnesota_boy · March 09, 2006, 06:22:13 AM

Have you changed out all the filters and checked the fuel line for a restriction or a valve in the line that might be mostly closed. Sounds like it isn't getting enough fuel. It also could need adjustment or rebuilding of the injector pump.

D._Frederick · March 09, 2006, 12:30:23 PM

I would go along with what Min. said, change the fuel filter and make sure that you have enough flow rate of fuel. Should be no less than a cup per minute.

gary · April 03, 2006, 08:09:58 PM

I changed all the filters oil,fuel and hydrulic. Adjusted the throtle. Changed a roller guide and leveled the blade. Then I tried to cut an old pine log a neighbor had in his yard for about a year( first time cutting pine)
the blade would get to about half way into the log and the engine would bog down.
Where do I check the fuel flow at? It might be that I think that this saw should cut faster than it is able to.

Furby · April 03, 2006, 08:23:58 PM

Have ya checked the blades?
Same blade, different blades?
Different logs?

Tom · April 03, 2006, 08:26:48 PM

Gary,

You are right. It could be that you are advancing the blade faster than the engine can take the strain. That is something to consider.

It also could be that the engine isn't being revved to it's working RPM's. My Kubota 40 horse runs at 3100 RPM's and still isn't up against the governor. You want enough sawing pressure that the governor will kick in on knots and twisted grain but not so much that you are sawing with the governor.

It's a difficult thing to suggest how fast to saw because there are so many variables, like width of log and density of wood. If your engine is bogging, back off. You want to keep the operating RPM's pretty steady.

Brad_S. · April 03, 2006, 08:29:30 PM

You should be able to move through white pine at a pretty fair clip, but if it's spruce, you need to go slow as the blade will dip and dive. The 21 hp Duetz is noisy but sufficient to power the mill.
Did you buy the saw from TH direct or from Ken Clouser in PA, and which are you calling for advice? TH is not all that versed in engine problems, when I experience one they call the Duetz distributor for me and echo back their thoughts.

Ivey · April 03, 2006, 10:13:31 PM

Check the fuel lines, if any are cracked or sucking any air at all then you will lose power.

This and fuel filters are a common problems for deisel.

gary · April 04, 2006, 06:09:41 AM

Furby I have changed blades. It happens with brand new blades from two different companys. I have had this problem with oak,maple,cherry, poplar and pine.
Tom I don't think this saw has a governor. The throtle is controled by a solinoid. I adjusted it so that on fast idle it is almost at as fast as it will go.
Brad I bought this saw from a private owner.He upgraded to a resaw,then sold the saw to his nephew who used the saw for about a year.The nephew made a few modifactions on the saw. I think he was having the same problems as I am. He moved the soloniod used to shut the saw off to work with the throttle . As I understand it he had a button rigged up so that when the engine bogged down he would push this button and hold it down for higher revs. The only problem with me doing this is he took most of the stuff off the saw before his uncle got it back and sold it to me. I think the log was spruce. I didn't have any problem with the blade dipping or diving. I will time how long it takes to make a cut. After I get back from having blades sharpened today. The only blades I have used have all been brand new. I am going to see if blades that have been sharpened make a difference.
Ivey If I had cracked fuel lines or was sucking air wouldn't this be a problem all the time? The only time this happens is after the blade is in the log

sawguy21 · April 04, 2006, 06:30:34 AM

The engine needs a governor to increase speed as the load is applied yet back off under light or no load to keep it from overspeeding. The owner's nephew may have jerry rigged it or defeated it entirely.

twoodward15 · April 04, 2006, 07:23:06 AM

Yep, I'd check the governor. The TH that I got to saw with would run right through the log like now! Make sure you aren't trying to run the head through too fast. The guy that taught me said to turn the knob (to advance the head) slowly and get it in the cant. Open it slowly, just until the engine barely starts to bog, then let it go through like that. If you aren't bogging at the beginning of the log then I can't see why it would start bogging at the middle unless you are opening the valve to advance the head too fast when you get it in the wood. After you set the speed, you aren't opening that valve more are you? There should be no speed adjustment on that mill except the switch you flip to run it WOT (wide open throttle). The governor should take care of the rest if it is operating properly.

gary · April 04, 2006, 07:42:51 AM

Twoodward I have a toggle switch for fast and slow idle and that is hooked to the soloniod. There is nothing else on the throtle. The valve you are talking about I set it so the head just strarts to move and leave it there and I have no problems. If I try and go any faster it bogs down in the middle of the log. The logs were all from 14 inch to about 24 inch.

chet · April 04, 2006, 08:51:47 AM

Gary,
Crack open yer bleeders and check for the presents of air in the system, this will also let you check fuel flow. Another thing to check is whatever system that engine uses to shut down, weather it be air or fuel, to make sure that system is fully open when not in shut down mode.

twoodward15 · April 04, 2006, 10:08:18 AM

OK, try this. With no log on the bed, start your head at the normal position. Raise the blade about 10-12 inches off the bed, tension the blade and make it turn. Flip the switch to wind up the motor and open the valve to start the head moving. Does the engine bog down in the middle? I'm wondering if your bed is twisted/bent and causing the heead to bind a bit. If someone loaded a really big log on it once and it got away from them it may have done some damage.

highpockets · April 05, 2006, 07:50:11 AM

Gary, I am no authority on much of anything but it sounds like the solenoid that was installed may not be pulling the fuel lever far enough to give you max power. If this previous owner was doing something to increase power, he must have had something to further advance the fuel lever. I have not seen one of these engines in years but if memory serves me, there is a fuel (governor) lever on the injection pump. There could be a problem with the pump that is not letting the internal governor open up under load. In my experience if you have assured yourself that you have clean fuel and filters, with no air leaks on the suction, then I'd look at the pump and or it's control.

barbender · April 05, 2006, 10:17:56 AM

Gary- the governor on that engine should be mechanical and part of the injection pump. Basically, in my experience, there are three things that will cause an engine to bog down. 1- too much load 2- starved for fuel 3 starved for air. I run a roller at work that has a duetz deisel in it, when it starts running out of fuel it acts exactly like you describe. As soon as you try to move, it starts to die, let off and it comes back up to speed. So if it starts to die I know its time to go fuel up! Since you say you changed the filters already, I would check to see if it is getting good fuel flow before the injection pump. The "correct" way to do this is to connect a diesel fuel pressure guage before the pump and check the pressure at lo and hi idle and see if they meet the spec for your engine. Does your fuel gravity feed from the tank to the engine, or does it have a mechanical or electric transfer (lift) pump? Most guys don't have a pressure guage in their toolbox though, I'd just check and make sure there is plenty of fuel being supplied to the injection pump, just run the line into a bucket or something to catch the fuel. It should be a nice even flow with no air bubbles in it. If the fuel flow is good, I'd suspect something is amiss with the governor or the injection pump itself. The way you say it dies out in the middle of a cut makes me suspect it is a fuel supply problem. If for instance, you started a cut and just rammed it into the log, does it bog or does it give more power? The duetzs we run have been good little engines, nice and simple. I don't know how many horse they are, they're a three cylinder I'd suspect 40 horse or so. The only problem we ever did have was with an injection pump, I think it was springs in the governor, the engine was poppin and snappin, sounded horrible. I didn't work on it myself so thats all I can tell you about it, and the fact that the parts were quite difficult to get. You might have to find a diesel mechanic for this one.

barbender · April 05, 2006, 10:21:29 AM

Gary- if you want PM me and I'll give you my phone #, if I could talk to you in person I could get a lot better idea what the engine is doing and give you a better idea about what to check on. I have a hard time coming across clearly typing things out.

gary · April 07, 2006, 04:55:52 AM

I think I got it fixed. I was able to cut a 1"x10"x9' in 50 seconds. Everything was going good until the last cut. Then the blade took a dive and I cut the the last clamp for holding the board.
Thanks for all the help

highpockets · April 07, 2006, 06:10:31 AM

But we want to know how you got it fixed.

8)

gary · April 07, 2006, 06:28:22 AM

As I said earlier I changed all the filters and that helped. While changing the roller guide I found one side of the blade was a half inch lower than the other side. But the big difference came when I adjusted the throttle. This saw has a piece of nylon webbing attached to the soloniod and the throttle and it had stretched and the holes for the bolts weren't holding it where it should have been. I think it was all these little problems adding up to make one big one. I'll know more tommorow I have a job cutting cherry but now its time for the 2 hour ride to cleveland to go work in the scrap yard.

gary · April 09, 2006, 09:07:48 AM

I took the mill out saturday and gave it a work out. It ran great no bogging down. I cut about 900 bft of cherry, 200bft of sassafrass, 300bft of oak. Only hit 2 pieces of metal in the biggest oak log about 28 inch diameter 2 cuts 2 pieces of metal. That one went into the firewood pile,they have an outdoor boiler that heats 3 house and an apartment it uses a pickup truckload of wood in 2 days. They brought the logs to the mill with a bobcat and sat the logs on the loader arms. That was nice no fighting to get my logrite cant hook(no one wants to use the old wooden ones) to roll logs out of a pile.
Twoodward I looked at the mill real close after you said that about it being bent. I found out that the frame or maybe just the track that the head travels on is bent a little. In the area where the loading arms are. I am about to go set the mill up in my yard and see what I can do to straighten it out some.
Thanks again eveyone for all the help
Gary

twoodward15 · April 09, 2006, 04:43:00 PM

If it aint broke, don't fix it. If it is bent and then you bend it back you may actually do more harm thatn good. If ti isn't hurting anything I'd leave it alone. you don't want to flex that metal too much, but I guess if it's an easy fix then press on. Glad she's running good for you now.

Brad_S. · April 09, 2006, 06:36:59 PM

Timber Harvesters are built with a camber in them. When you set up to saw, you jack up each end to get the camber out. Eyeballing down the track is good enough, I usually over compensate since when you release the jack, it settles down some.
There is a piece of angle iron that runs along the side of the track that often gets bent when protrusions from large, heavy logs hit it. All this piece does is act as a stop for the four fingers that hang from the frame that keep the head from toppling off if something should strike the head. They need not be straight to function properly unless the fingers get hung up on them as they pass under. I concur with twoodward15's comment.
50 seconds for a 9' cut seems excessive. Did you pick up some speed Saturday? The diving blade can either be a blade issue or a guide issue. Do you know how to level the blade to the bed?

gary · April 09, 2006, 07:21:32 PM

Brad The piece of angle is what is bent. I noticed the head hanging up on it when it goes over the bent spots, Its not getting stuck in these spots but just seems to jerk when it goes over them. The 50 seconds was the only time I timed a cut. I did manage to get it to cut a little faster on saturday. I think it should have cut faster. I am going to try going faster on my own logs then if i ruin a few boards no one can complain. How fast do you think I should be able to make a cut in a oak cant that is 8"x 7"x 12'? I do know how to level the blade to the bed. When the blade took the dive it had hit a knot. It just made me mad cause it was a brand new blade and I had made 3 cuts before it did that. It couldn't have done it on the cut before that because then I would not have hit the dog with it. I have the saw set up in my yard now. To get it level I had to put 2 pieces of railroad tie under each of the front legs and put them almost all the way down. The back of the saw is only about 2 feet off the ground. Thats just because I live on a hill and is only a temporary thing while I work on it.
Have you had any problems with the belt tensioner? The bolt that holds mine to the lube tank is bent and started to leak around the weld. I think I am going to cut it off and have someone weld a new one on.

Brad_S. · April 09, 2006, 07:43:21 PM

I'm used to the 30 hp deisel and would cover a foot of length in about 2 seconds with a sharp blade on something that narrow. I cant imagine it taking much more than 3 seconds per foot on a 21 hp. So many variables though.
I can't even imagine how the tensioner bolt could get bent. Your poor machine must have led an abused life at the hands of the previous owner!

twoodward15 · April 09, 2006, 08:21:37 PM

Yes, I agree with Brad on the timing. 50 seconds seems excessive. I'm wondering if the engine is bogging down during the cut. It makes me think you are trying to cut too fast and that is actually what is slowing you down. maybe back off the feed a bit? Hmmmm. In an 8 by 7 cant you should be sailing through like there isn't even any wood there. We were cutting 32 inch (limit of the mill) walnut and she was humping through no problem. This is with the 30 horse deutz as well though. Is that fuel pump adjustable? maybe turn that thing up a bit to try to get some more power if it seems week? I'm at a loss for now. I'll think about it some more.

gary · May 01, 2006, 04:57:28 AM

An update on the problems with my mill. Brad S came down on sunday. He looked the mill over and made a few adjustments on it . Then he showed me how some things were supposed to be (before the Amish modifications). He said it was cutting at about the right speed now. I am going to put a tach. on it so I can see what my rpms are. Will a tach from a car work on a diesiel engine or do I need one for a desiel engine?

sawguy21 · May 01, 2006, 08:57:41 AM

Auto tachs work off pulses from the ignition system which the diesel does not have. The older ones often had a mechanical drive on the back of the alternator or other accessory. The new computer controlled engines may probably have a more sophisticated system.