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Tuning A Wisconsin Engine

bolens 850 wisconsin engine

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#1 MailmAn OFFLINE  

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Posted August 02, 2012 - 11:31 PM

I have some questions about fine-tuning a Wisconsin S8D engine on my Bolens 850. I have been fiddling with the governor linkage on the engine for some time now to try and get it working properly. I think I'm close, but it still acts weird to me... I know it is an old cantankerous engine and I'm lucky it runs as well as it does (or at all!), but I'd like to get it running as perfectly as I can. Right now it seems to start fine and idles just okay (although it does smoke profusely at really low RPMs before it finally stalls out). But it always starts right up everytime and doesn't stall out ever, which is good!

The biggest concerns I have with it are that it seems to run very hot all the time, it sounds like it is knocking at really high RPMs (unless it is under a decent load, like when the blades are running), and it seems to vary the RPMs a bit after you've been using it for a long time. First, as far as heat goes, the muffler seems to get really hot in no time. The first time I started it today, I noticed the throttle linkage got hung-up and the engine was stuck at WOT just after I started it, so I shut it off right away. Even after running for not even 20 seconds, the muffler was already too hot to touch! Why should it get that hot that quickly? Could something be clogging it? Or is the engine really running that hot? I also notice that the engine gets much too hot to touch after running it for only a few minutes and seems to take a while to cool down after it has been shut off. No idea if this is normal or not. I've never seen a small engine run this hot before.

The second thing is the engine sounds like it is knocking at high RPMs. At first I thought it might just be some sheet metal or something rattling around when the engine is running fast, but the more I hear it the more I'm worried it is the engine knocking. What would cause this? It seems to quiet down a lot when it is under a heavy load, like when the blades are on and I'm cutting grass. But once I shut the PTO off, the engine revs up a bit higher and the knock is very evident, even when I'm driving in 3rd gear with the deck off. I'm worried I may damage something internally if the knock persists. Is this just from ethanol in the gas or what? I'm running Star-tron and lead additive in the fuel of the Bolens. I use Sunoco 93 octane. Should I run a lower octane gas if it is running too hot and knocking?

The last thing is with the RPMs varying. IDK if this is normal operation with the governor setup or what. Like if I'm mowing uphill (it doesn't even have to be a very steep grade) it sounds like it bogs way down even with the throttle as high as it goes, but then when you're on a flat surface or going downhill, the engine sounds like it starts to race way up. Is that how the governor is supposed to work? If anything, I'd think it should be racing the throttle up when it starts to bog down and cutting the throttle when you're going downhill. I've tinkered with the throttle and governor linkages for some time now and I keep moving the throttle spring around trying to get it to run right, but it has been a battle for sure. :wallbanging:

Does anyone have any ideas for why my engine acts the way it does and if it is normal or if there are adjustments I should be making to get it to run properly? If I can, I'll try to get some video of the engine running so you can see and hear it. I know that is much more helpful than all the words I can type here to try and describe the symptoms!

#2 LilysDad ONLINE  

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Posted August 03, 2012 - 07:36 AM

it does smoke profusely at really low RPMs before it finally stalls out). But it always starts right up everytime and doesn't stall out ever, which is good!
Which is it? It stalls or it doesn't stall?

You seem to have a number of different issues going on. You need to start with a good cleaning and tune up.
it seems to run very hot all the time....... it sounds like it is knocking at really high RPMs........ it seems to vary the RPMs a bit after you've been using it for a long time....... , I noticed the throttle linkage got hung-up and the engine was stuck at WOT........

I'm not the expert here, but they will be along in a minute.
Heat first thing, I would check the timing, also make sure the engine fins/shrouding is clean.
Knocking could be a loose rod or it could be carbon build up on the piston.
It's pretty hard to set the governor by guess. Check the manual. Do you have access to a manual?
Throttle linkage should not be 'hanging up'. Repair properly.
These are a low compression engine. they do not need or like high octane gas.
So, as you see, you have some things to do. Clean the engine do a proper tune up( plugs, points, condenser, set points, check timing. change oil, use 30W oil, etc.) then pull the head off and remove any carbon. Find out the factoryt setting for the governor. Then if this still knocks you've got a bigger problem.

#3 MailmAn OFFLINE  

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Posted August 03, 2012 - 08:29 AM

I did read the manual on how to set the governor. Near as I can tell, it is correct. The adjustments I am making are moving the spring around on the governor linkage that goes to the throttle cable. There are 8 holes you can position it in that are supposed to roughly dictate max engine RPM. I thought it was running too high in the hole that was farthest down, so I moved the spring up to hole 4. There, it seemed to run well and didn't rev too high, but under load, the engine bogged way down and couldn't compensate enough, so I moved the spring to hole 6. It is not bad, but when running the deck it feels like it could give a bit more to spin the blades faster for a better cut.

How do you set the timing on these engines? Is that just a matter of adjusting the points? There is no distributor on this engine to adjust. I did do a "tune up" on it before I started using it. I put a brand new Autolite spark plug in it to replace the rusty and crusty old Champion plug. I also bought a brand new spark plug wire as the old one was pretty cracked, oily, and otherwise shot. I didn't want to run it with that plug wire. The coil is still original as well as the solenoid and voltage regulator.

I have thoroughly cleaned off the engine before using it and cleaned out the air passages. There was a lot of black crud all over the engine (as well as the body). No idea what it was - just grease and sludge or possibly some kind of mold or moss? The front grille screen on the flywheel is clean and open. It also has a brand new air cleaner on it. Here are the before and after pics:


BEFORE:

Posted Image


Posted Image




AFTER:

Posted Image


Posted Image



I also sprayed down all the throttle/governor linkages with PB Blaster to be sure they move freely. I haven't taken the carb off of the engine but before using it, I took the air cleaner assembly off and sprayed some carb and choke cleaner down the intake tube and let it sit for a while to try and clean any gunk out of the carb. I also put some carb cleaner additive into the first tank of fuel to try and clean the jet out a bit.

The throttle linkage got hung up because like an idiot I was trying to take the spring off to move it into another hole and I accidentally bent the governor rod out a bit so it hit a bolt on the engine shroud. I bent the rod back in so it would clear and it works fine now. :booboo:

The oil level and the oil itself looks fine. The guy I bought it from did an oil change on it before I bought it and the oil looks pretty fresh in it. I figured I'd change it at the end of the season or maybe the start of next season. It hasn't gone down any to indicate a leak or that it is burning excessive amounts of oil or anything.

Just about the only other things I have not checked or changed on it (for fear of making it NOT work at all b/c I'm not familiar with them...) are the points and condenser. I'm assuming they are under the box on the right side of the engine that says "Stop" on it?

Edited by MailmAn, August 05, 2012 - 10:18 PM.


#4 MailmAn OFFLINE  

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Posted August 03, 2012 - 08:36 AM

Which is it? It stalls or it doesn't stall?


What I meant is that under normal operating RPM ranges it has never stalled on me. Yes, it does eventually stall on me if I push the throttle in all the way and let it "idle" at a really low RPM. It also smokes a lot, but I'm assuming that's in part because it's not getting much air either if the throttle plate is shut all the way. Sorry, forgot to address this in my previous reply. I put this in my original post because it seems a lot of people were having issues (like the guy with the Kohler K161) with the engine running hot and then quitting after 5 minutes and not starting again. I am not having this issue. It just seems to be running hot to me and knocking, but it keeps on running despite this.

Hopefully video to come soon so you can see what I'm talking about... :wewantvideo: (<-- I know this is usually YOUR guys' cue, but...)

Edited by MailmAn, August 03, 2012 - 08:39 AM.


#5 Bolens 1000 ONLINE  

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Posted August 03, 2012 - 09:24 AM

If the engine is running as hot as you describe, I would check your timing and valves/clearances. An engine slightly out of time will run hotter than its supposed to. Have you taken the head off yet to clean the carbon and check if the valves are seating properly? A build up of carbon will also make the engine run hot.

What color is the smoke? Blue or black? If its blue/white in color then that indicates you are burning oil and the engine is going to need some attention down the road which is expected for a 40+ year old engine.

The knocking can only be about 3 things:
-Build up of carbon
-Improper timing (Advanced spark)
-Worn out connecting rod or piston pin.

#6 Bolens 1000 ONLINE  

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Posted August 03, 2012 - 09:29 AM

This may be of some help to you:
This was in another Thread posted about a year ago about how to time the wisconsin engines

Disconnect the wires going to the ignition points terminal on the outside of the breaker box. .....Rotate the engine on the compression stroke until the timing mark on the flywheel lines up with the pointer on the shroud. .....(If you overshoot the mark, turn the engine backward 1/2 turn, then SLOWLY rotate forward until the timing mark lines up EXACTLY with the pointer.)

Connect a continuity tester between the ignition point terminal and ground. .......Without turning the engine, adjust the point setting until an open circuit is indicated (light goes out, buzzer silences, or meter goes to infinity).

The ignition coil fires when the points OPEN. ......Rotate the engine backwards, and then forward to re-check that the points open EXACTLY when the timing marks line up.

.....Re-adjust the points if necessary, as the adjustment is very sensitive, and will change as the point clamping screw is tightened.


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#7 MailmAn OFFLINE  

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Posted August 03, 2012 - 07:47 PM

This was in another Thread posted about a year ago about how to time the wisconsin engines:


Are there any pics to accompany this so I know what I'm adjusting and how to do it? If not, could someone take some? If I was to do this on my tractor, I'd try to take pics, but I need to be comfortable with what I'm doing first before I can make a How-To video or something...

I have not taken the head off yet or otherwise dismantled the engine. I'd need a rebuild set if I were to attempt this so I can re-gasket everything when I put it back together. Like I said, it seems to run for now, so I don't want to mess with it unless I'm sure I know what I'm going in to fiddle with. If I were to start taking it apart, it would probably be towards the end of the year to do a complete rebuild on the engine over the winter. But I'm not sure that it is THAT far gone yet to warrant rebuilding the entire engine. I'm just looking for some small things I can adjust to help it run better for now.

Video is coming soon (hopefully), as soon as I get time to edit the footage together. Sometime this weekend I hope I'll have it done. I shot some video earlier today before I mowed someone's lawn.

#8 LilysDad ONLINE  

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Posted August 03, 2012 - 08:21 PM

Removing the head is not that big of a deal. You just need a head gasket and a torque wrench to put it back on.

#9 MailmAn OFFLINE  

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Posted August 05, 2012 - 10:26 PM

Okay, I was busy working all this weekend, but somehow managed to get the video all edited together! I'm uploading it to YouTube right now, so it might not be available yet. If the video doesn't work right now, try coming back in like 20 minutes or so to see if it has finished uploading yet. I just wanted to post this now so I can go to bed already!



So, check out the video of my engine running and let me know what you think! Is it acting weird or is it just me going crazy? :wacko: Like I said, I'm not really used to these older engines and how they operate. I hope it is just something stupidly simple to adjust to get it running in tip-top shape!!!


Thanks in advance!!!

#10 Bolens 1000 ONLINE  

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Posted August 06, 2012 - 06:52 AM

Looks to me like you have too much play in the linkage which may be the cause of the delayed reaction. Looks like every time you move the throttle, the rod and spring dip down on the valve cover and they should be tighter than that. Did you drill those 2 other holes in that rod the spring is attached to?
The Governor lever also looks to be pretty wobbly, which it shouldn't have that much play in it.

Your throttle cable also appears to be creeping back. The throttle cable should lock in place when you twist it. Many times these wear out. Replacements can be bought for less than $20.

I think your starter is going to need some attention as well as it shouldnt be struggling to turn the engine over like that. The ammeter indicated its not working the right way (Shouldnt be bouncing around like that) Have you tested to see how many volts the starter is putting out when running??
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#11 Bruce Dorsi ONLINE  

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Posted August 06, 2012 - 09:08 AM

I think 90% of your issues can be resolved with correctly adjusting things.

I know !! --- That doesn't help you !! ....But I don't know how to adequately describe how to make all the adjustments to you.

We are approx 3-1/2 hours apart. .....If you were close, I would gladly offer my help. ....I could probably do the adjustments faster than I can try to explain what to do. (I'm not trying to be a smart-a**, I am just frustrated that I can not verbally describe all that has to be done in a manner which will not confuse you more!) .....There is also some terminology which can be confusing.

I will think further about how I can organize my thoughts so they are clear to you.

In the meantime, here are some things to consider:

The knocking noise may be caused by internal or external engine parts. ....Hopefully, the problem is external. ....A loose flywheel or engine pulley (Did you install a new key?) can cause a knocking noise. .....On Wisconsin engines, it was not uncommon for the flywheel-mounted (starter) pulley to become loose and enlarge the mounting holes. ...This would cause a knocking noise, as well.

When the belt idler pulleys fail, they usually produce a whining noise instead of a knocking sound. ....On your tractor, you can put the Hi-Lo range selector midway in its travel. ....This should move the idler away from the belt, to eliminate the idler pulley as a source of the knocking.

As others have said, carbon in the combustion chamber can also cause the knocking noise. ....This is preferable over a loose connecting rod, worn piston, or loose piston pin, which are other possible causes.

Incorrect ignition timing will cause poor performance, and may cause the knocking noise. .....These Wisconsin engines are very sensitive to the timing, so it is important that the timing be correctly adjusted!

While i think many of the issues can be corrected with adjustments, air leaks at the throttle shaft or intake gasket, will hamper any efforts to establish stable running. ....Usually these air leaks have more affect at idle speed than at high speed.

It's hard to tell from your video, but I think one of your problems is that the idle speed is too low. .....Also, using a tach is the best way to set idle and high speed rpms. .....An idle speed that is too low, will cause stalling, while a too-high governor setting will allow the engine to overspeed and self-destruct.

The smoking (which appears to be oil smoke) can be caused by a worn cylinder, piston, piston rings, valve guides, or a scratched/scored cylinder. .....Black smoke is caused by a carb mixture problem, or faulty ignition.

The purpose of the governor is to try to maintain the set engine speed, by responding to load conditions. ....It is quite common for the engine to bog slightly, or speed up, until the governor can respond. .....Having linkage adjusted properly minimizes the response time. .....Low power under load can be caused by improper governor or carb settings or loss of compression.
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#12 MailmAn OFFLINE  

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Posted August 06, 2012 - 05:18 PM

Looks to me like you have too much play in the linkage which may be the cause of the delayed reaction. Looks like every time you move the throttle, the rod and spring dip down on the valve cover and they should be tighter than that. Did you drill those 2 other holes in that rod the spring is attached to?


I originally thought that myself, but every time I try to "tighten" the throttle linkage to take some play out of it, the engine revs up way too high. Unless the governor/throttle return spring is just way too weak to keep everything in check? If you'll notice, the throttle spring (at the bottom) is pretty beefy compared to the tiny little governor return spring up top. Could this be part of the issue or is this spring supposed to be very weak?

I did not drill out any holes on the governor linkage. It is supposed to have 8 holes in it. This supposedly adjusts the max RPM the engine will run at. The higher up the throttle spring is moved, the lower the top end RPM will be. The lower you move the spring, the higher the top end RPM will be. Right now, I have it set one hole down from the max RPM the engine will go. According to the Wisconsin engine manual, the 8th hole (farthest towards the bottom) will operate the engine at a max of around 3800-3900RPM. The 7th hole I have it in should operate it around 3600-3700RPM.


I think your starter is going to need some attention as well as it shouldnt be struggling to turn the engine over like that. The ammeter indicated its not working the right way (Shouldnt be bouncing around like that) Have you tested to see how many volts the starter is putting out when running??


The battery currently has around 16.5VDC when I put a volt meter on it. When the starter is engaged, I think it drops to like 13-14VDC and when the engine is running, the volt meter keeps reading right around 15.8-16VDC. It doesn't seem to drop at all, so I'm assuming it is charging the battery. I'll probably have to look into having the starter/generator rebuilt soon because I don't like how slow it turns the engine over (or not at all sometimes and I keep having to bump the starter!). Sometimes I also see a little puff of smoke come out of the starter towards the back when it is really struggling to turn over. I turn the key off and let it sit for a few seconds before trying to start it again when this happens.

#13 MailmAn OFFLINE  

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Posted August 10, 2012 - 08:48 AM

I know I haven't even had the tractor around this week since it has been at the shop getting the rear axle free-wheel pin housing welded up since I stupidly cracked the cast iron off trying to get the rusted/frozen pin out a while ago... So I haven't been able to work on tuning it anyways, but any further thoughts from anyone on the engine? I've never adjusted points on an engine before (all of my stuff has been newer from the mid-70's and later that has solid-state ignition) and aren't really sure on the procedure. I also don't know if I have the right equipment to do it or not. I don't have a dwell meter or anything for one. I've also been looking for manuals that tell you how to tune the carb properly. However, the most I can seem to find on it are Wisconsin engine parts manuals that don't tell you how to tune the engine. The Bolens manuals usually don't get into tuning your engine either and just go through basics like how to start the engine and where the air cleaner and fuel filter are and how to clean them.

IDK if at this point I should just take it to a repair shop and see if they can adjust everything for me, if they have ever even seen a Wisconsin engine at all? Of course, I'd like to learn how to do it myself not only just so that I don't have to pay someone to work on it but because I like learning things like this and how to get things working properly.

Bruce - Where are you located in NJ? I missed out on a Trac-Vac in Ringoes, NJ. Might still have a lead on some other parts in PA I may be trying to get for my snowblower and some other things, so I might eventually make a trip down that way. If I could coordinate everything, maybe I could load up the tractor and take a drive down that way if you think you could tune up the engine for me real quick and teach me how to do it right! Just a thought... It would most likely have to be on a weekday though too as I work on the weekends now. Not sure what your schedule is like....

#14 Bruce Dorsi ONLINE  

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Posted August 10, 2012 - 10:08 PM

Bruce - Where are you located in NJ? I missed out on a Trac-Vac in Ringoes, NJ. Might still have a lead on some other parts in PA I may be trying to get for my snowblower and some other things, so I might eventually make a trip down that way. If I could coordinate everything, maybe I could load up the tractor and take a drive down that way if you think you could tune up the engine for me real quick and teach me how to do it right! Just a thought... It would most likely have to be on a weekday though too as I work on the weekends now. Not sure what your schedule is like....


My schedule is pretty flexible. .....I am in Bridgewater, NJ, 08807, about 8-10 minutes from the junction of I-78 and I-287.

Edited by Bruce Dorsi, August 10, 2012 - 10:17 PM.


#15 Bruce Dorsi ONLINE  

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Posted August 10, 2012 - 10:14 PM

According to the Wisconsin engine manual, the 8th hole (farthest towards the bottom) will operate the engine at a max of around 3800-3900RPM. The 7th hole I have it in should operate it around 3600-3700RPM.

Which manual are you looking at?

The battery currently has around 16.5VDC when I put a volt meter on it. When the starter is engaged, I think it drops to like 13-14VDC and when the engine is running, the volt meter keeps reading right around 15.8-16VDC. It doesn't seem to drop at all, so I'm assuming it is charging the battery. I'll probably have to look into having the starter/generator rebuilt soon because I don't like how slow it turns the engine over (or not at all sometimes and I keep having to bump the starter!). Sometimes I also see a little puff of smoke come out of the starter towards the back when it is really struggling to turn over. I turn the key off and let it sit for a few seconds before trying to start it again when this happens.


Are you sure your voltmeter is accurate? ....I have never heard of a 12volt battery having 16.5 volts.

Can you check the voltage of your car/truck battery to see if your voltmeter is wrong?

Edited by Bruce Dorsi, August 10, 2012 - 10:15 PM.






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