I've had an issue with my LT40 where if I adjust my brake strap as per the manual, there is not enough throw taking place to open and close the throttle on my Lombardini diesel engine. The manual says with the clutch engaged, loosen the retaining bolts and push the brake strap down until it touches the brake drum. If I do that, it is a nice short clutch lever throw, and the belt disengages- great! However when disengaged my engine is still at about ¾ throttle😵💫
I end up loosening my brake farther and farther, until there is enough movement to fully cycle the throttle from idle to open. This makes for a long clutch throw that wears on the arm on a full day, and recently I think it is the cause of a new problem- I have a (bad) habit of starting engines on cold days to let them warm up, getting distracted, and realizing that something had been running for an hour. In this case it was my sawmill engine running, when I went to start sawing, I engaged the clutch and my drive belt (that had about 20 hours on it) fell right off. It had apparently been rubbing on the engine pulley enough to get hot enough that it almost looked like it had been on fire. Broke right in half where it burned.
The belt I had just replaced had over 1000 hours on it without issue, and it had experienced many hours of idle time as well. I'm not sure what is different or causing this issue, I just know something ain't right. I suspect it is because my belt has so much slack in it when disengaged, it may be trying to "re-engage" itself?
I do have the drive belt "stand off pin" or whatever it is called, adjusted to what I think is spec? I've seen anything from 1/4" to 1/16" or as close as you can get it without rubbing the belt when engaged. Different WM manuals have a different spec for it, I couldn't even find it in my manual. Currently it is spaced close, I put a credit card in between for spacing (about 1/16").
I installed a new drive belt ($140+ delivered😵💫) and as I have the engine idling, it is chirping and squawking occasionally as the belt tries to drag.
Here's a picture of the amount of slack in the belt when disengaged.
(https://forestryforum.com/gallery/albums/userpics/11286/20221122_142356.jpg?easyrotate_cache=1669150201)
adjust throttle cable
I had similar problems once.
You first have to have your drive belt the right tension.
Then you need to have your brake belt adjust so that it works properly based on that tension setting.
After those two are right you adjust your throttle cable until it works properly as well.
All are connected and have to be adjusted to make your machine work correctly.
Good luck.
Jim Rogers
Drive belt is adjusted properly to 18 lbs at 7/16" deflection per the WM belt tension gauge.
Agree, need to adjust, relax, the throttle cable as you adjust, tighten the brake mechanism.
Ok, look at this from the other direction. If I set the brake strap per the manual, and then adjust the throttle so it is at idle when the clutch is disengaged, it only hits about 1/2 throttle when I engage the clutch. I guess if I had the operator's seat I could just put a foot feed on it😁
At one time or the other I have experienced all of the above from the brake, throttle cable, drive belt chirping, etc. My drive belt chirping problem was solved by adjusting the auto clutch which was out of sync. Once that is correct some of the other issues should disappear. Moving the throttle cable further away from the engine pivot point should give you enough movement to be be slack at idle and against the spring at sawing speed.
Could it have anything to do with the engine swap? Different linkage length at the injection pump?
I haven't swapped the engine yet, Southside- the original Lombardini lives on. But I think you're barking up the right tree. I'm kinda wondering if I'm missing a part or something. All the mechanism is, as it sits, is the throttle itself with the cable connected to it. It has an adjustment at that point, then goes to another guide that is mounted to the block, with another point of adjustment. From there the cable just goes down to where it mounts by a spring, at the base of the clutch lever.
Well the dogma of it for sure sounds like you need to hound it until you have more bite and less bark. Just be sure to keep the linkage on the right side of the fence and nobody will have a bone to pick with you. ;D
The most engine travel is the furtherest away from the pivot which would give the widest range of throttle movement. When I added the auto clutch I had to do some rerouting to get enough throttle movement. When I made the engine swap (s) I again had to do some fancy footwork to go from idle to full throttle. Even now my idle is a bit fast but I have all that I'm gonna get.
Knowing that you have the same mill as me, Magic (engine and everything) I appreciate your insight. I will see what I can do to reroute it.
Southside, I forgot that barking hounds is a bit of a trigger for you right now😂
Just a thought, are you sure the drive belt you put on is the correct one? Also curious what started the problem initially?
Maybe a parts book or diagram may help pinpoint potential missing or bent parts.
Just checking but are you running without the lower cover? That puts the belt in the correct position to allow slippage of the belt.
Good point. Yes, the lower cover must be in place for proper belt operation.
Yes, there are operators that successfully run without it.
Yes, I was. Bad habit. When I first got this mill used, the previous owner had really bungled it up (one of those people that it should be against the law for them to own equipment). They had been spraying white lithium grease all over everything, instead of ATF. It had turned to glue with the addition of moisture and sawdust, so my linkages and levers, and throttle cable were all bound up or gummed up. Nothing worked right. So in the process of straightening that all out, I had that guard off and on who knows how many times, and I eventually must've pitched it out in the weeds in frustration. We're talking maybe 15 years ago😳
So I was thinking the same thing, that gaurd would keep the belt from sagging on the bottom and help the issue, so I went and found it and will get it bolted on today.
That's a pretty funny story.
What else you got out there in the weeds?
Hahaha I could go on and on!😂 Not my wife's favorite trait, I'll say that. There's always vehicles, lumber piles, piles of wood and other goodies trying to creep up on the edge of the yard😁
Is your old D Max out there?
It sure is! Just patiently waiting for me to have time to work on it, which may be never😁
Hello,
As the drive belt wear the travel gets longer. This may effect the travel for your shoulder. There is a adjustment for the handle and the brake also keeps your fingers from getting smashed on the radiator. The brake strap also keeps the engine from traveling to low. The pin on the engine helps to keep the belt from dragging on the engine pulley. Engage the engine ( with out running) set the pin with day light between the belt and the pin, not rubbing while engine is running. As the engine mount and pin wear the engine will start to turn and get the belt alignment off some. Hopefully you have changed the original rubber engine mounts to the new design aluminum with brass bushing? I am trying to picture what you may be experiencing.
Hope this helps.
M
Thanks Marty, yep I replaced the rubber engine mounts with the aluminum ones recently.
My brake strap adjustment is completely subservient to my throttle control. I have to loosen the brake strap farther and farther until there is enough throw to pull the throttle cable enough to fully open and close the throttle against the stops.
Quote from: barbender on November 22, 2022, 06:30:37 PMIf I set the brake strap per the manual, and then adjust the throttle so it is at idle when the clutch is disengaged, it only hits about 1/2 throttle when I engage the clutch
You say you adjusted the throttle, but did you adjust the cable? Section 2-12 in the engine manual will show you how to do both.
Engine Manual_ D40 (1997+ Master).pdf (http://file:///C:/Users/jlbenitz/Documents/Documents/sawmill%20stuff/Manuals/Engine%20Manual_%20D40%20(1997+%20Master).pdf)