The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems

Chainsawr, The Worlds Largest Inventory of Chainsaw Parts





Author Topic: Onan 24hp woodmizer mill will not start, please help  (Read 10151 times)

0 Members and 1 Guest are viewing this topic.

Offline bitsy4643

  • Member*
  • *
  • Posts: 1
    • Share Post
Onan 24hp woodmizer mill will not start, please help
« on: October 09, 2010, 05:18:03 PM »
Woodmizer sawmill with Onan 24hp engine quit running in March. Cannot get to run again after doing the following. Ignition module bad. Replaced, first replacement dead out of box.
Pulses to coil from new module in precise time as per Onan specs. No fire at plugs. Bought new Onan dual coil, still no fire to plugs. Checked ohms specs as per Onan manual, stating 19800 ohms max on top end. Reading was 21,600 ohms. Called Woodmizer who pulled new coil from stock. Same Ohm reading, which they could not explain. Took non-firing Onan coil off Woodmizer and put on Kohler engine with mechanical points. plug fired great and Kohler engine started right away and ran fine. Took coil back to Onan engine, still no fire. [Tech said mechanical points deliver much more voltage].
Bought two 12 volt coils on Ebay for 4.99 each. wired correctly together, now have best spark as ever, but engine just sputters and spits gas up carb, and backfires at times.
Could governor have any effect on engine not wanting to start at all, even with great fire at plugs and fresh fuel?  Thanks for any help :-\

Offline logwalker

  • Senior Member x2
  • *****
  • Posts: 1629
  • Age: 69
  • Location: San Juan Island, WA 98250
  • Gender: Male
  • Got Logs??
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #1 on: October 09, 2010, 05:50:08 PM »
I would start with a compression check and see if the valves are seating properly. Joe
Let's all be careful out there tomorrow. Lt40hd, 22' Kenworth Flatbed rollback dump, MM45B Mitsubishi trackhoe, Clark5000lb Forklift, Kubota L2850 tractor

Offline isawlogs

  • Senior Member x2
  • *****
  • Posts: 8193
  • Age: 60
  • Location: Chelsea Québec
  • Gender: Male
  • A smile is contagious ... Start an epidemic
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #2 on: October 09, 2010, 06:08:35 PM »
there is a black wire going from the coils down to ,control box ..... Check that this wire is not broke . If it is , your engin will never start no matter what you change .
A man does not always grow wise as he grows old , but he always grows old as he grows wise .

   Marcel

Offline jbuck984

  • member
  • *
  • Posts: 14
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #3 on: October 09, 2010, 07:05:02 PM »
does is sputter like its getting to much fuel? Could b float? Check if the plugs are wet or turn it over with a plug out and see how much fuel is coming out. That happened on my kohler after it sat for some time. Is the coil ground wire in good shape (been mentioned) could have gotten nicked and partially grounding? Not sure if you can on that engine but I like to pull that wire off the coil to troubleshoot sometimes.

Online Magicman

  • Senior Member x2
  • *****
  • Posts: 39892
  • Age: 76
  • Location: Brookhaven, MS
  • Gender: Male
  • A "Traveling Man"
    • Share Post
    • Knothole Sawmill
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #4 on: October 09, 2010, 07:10:01 PM »
Backfiring usually indicates a timing problem.

I'm not familiar with your engine, but I know with small engines such as lawnmowers and tillers, the flywheel will shear the key and turn on the crankshaft.  All of the spark in the world won't crank it then.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Offline buildthisfixthat

  • Full Member x2
  • ***
  • Posts: 136
  • Age: 52
  • Location: northern wood & rock area
  • Gender: Male
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #5 on: October 09, 2010, 07:22:53 PM »
you may want to check the intake manifold gaskets i had a onan engine that was hard to start ,misfired ,and sometimes backfired ran hot also due to running lean on one cylinder everything check out good comp,ign,fuel,ect  at wits end as i was starting it  it sneezed  a puff of smoke trom the intake gasket the gasket was half gone ,replaced gasket ran great again
shop built bandsaw mill

Offline buildthisfixthat

  • Full Member x2
  • ***
  • Posts: 136
  • Age: 52
  • Location: northern wood & rock area
  • Gender: Male
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #6 on: October 09, 2010, 07:27:48 PM »
Woodmizer sawmill with Onan 24hp engine quit running in March. Cannot get to run again after doing the following. Ignition module bad. Replaced, first replacement dead out of box.
Pulses to coil from new module in precise time as per Onan specs. No fire at plugs. Bought new Onan dual coil, still no fire to plugs. Checked ohms specs as per Onan manual, stating 19800 ohms max on top end. Reading was 21,600 ohms. Called Woodmizer who pulled new coil from stock. Same Ohm reading, which they could not explain. Took non-firing Onan coil off Woodmizer and put on Kohler engine with mechanical points. plug fired great and Kohler engine started right away and ran fine. Took coil back to Onan engine, still no fire. [Tech said mechanical points deliver much more voltage].
Bought two 12 volt coils on Ebay for 4.99 each. wired correctly together, now have best spark as ever, but engine just sputters and spits gas up carb, and backfires at times.
Could governor have any effect on engine not wanting to start at all, even with great fire at plugs and fresh fuel?  Thanks for any help :-\  no the governor should not give you this problem though he is smart but no
shop built bandsaw mill

Offline Buck

  • Senior Member x2
  • *****
  • Posts: 1167
  • Age: 54
  • Location: Asheboro, NC.
  • Gender: Male
  • Another "traveling man"
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #7 on: October 09, 2010, 10:28:09 PM »
That lil black wire and that dang carburetor caused me the same problems, I would have sworn I had a bad coil. and/or plugs.
Respect is earned. Honesty is appreciated. Trust is gained. Loyalty is returned.

Live....like someone left the gate open

Offline Jeff

  • Fearless Leader
  • Administrator
  • *****
  • Posts: 49673
  • Age: 58
  • Location: Harrison MI
  • Gender: Male
  • I know that I do not know.
    • Share Post
    • THEE Forestry Forum
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #8 on: October 09, 2010, 11:07:31 PM »
When I was having coil problems, It was my understanding that trying to use duel coils to replace the expensive onan coil would not work.  Call sparks (Rick Lauman) at wood-mizer.

Sounds to me that your replacement coil was bad and like they told me, the duel coil setup just does not work right.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life.
Ezekiel 22:30

Offline isawlogs

  • Senior Member x2
  • *****
  • Posts: 8193
  • Age: 60
  • Location: Chelsea Québec
  • Gender: Male
  • A smile is contagious ... Start an epidemic
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #9 on: October 09, 2010, 11:10:52 PM »

 While checking the litle black wire , make sure that the connector at the coil is clean, if not ya wont ever get her started
A man does not always grow wise as he grows old , but he always grows old as he grows wise .

   Marcel

Offline Hilltop366

  • Senior Member x2
  • *****
  • Posts: 2822
  • Location: Nova Scotia
  • Gender: Male
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #10 on: October 10, 2010, 11:07:05 AM »
With the backfire and sputtering it sounds like timing like MM said.
Some engines are real fussy about the flywheel nut torque, if it has not been tightened properly the flywheel will turn on the crank shaft when turned over by the starter and be out of time,

I have no experience on Onans so i am not sure how the ignition is set up on these but another thing that can cause a week spark is the gap between the coil and flywheel if set up that way also rust on the out side of the of the flywheel.

When trouble shooting with no obvious reason for the engine not working I try to start with one thing a work by process of elimination by thinking back to my small engine school days, "FACTS" was drilled in to us, it stands for Fuel , Air, Compression , Timing , Spark.  Once a problem with one of the FACTS is found I like to work from one end to the other or from both end to the middle of a system to find the reason for the system not working. If it has no spark I will start at the ignition switch and then the spark plug and work my way to the middle to find the reason for it not working.

Offline MartyParsons

  • Senior Member x2
  • *****
  • Posts: 1863
  • Age: 56
  • Location: Shade Gap, Pennsylvania
  • Gender: Male
  • Wood-Mizer Service and sales PA, VA, MD, WV others
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #11 on: October 10, 2010, 08:06:09 PM »
It sounds like a bad trigger on the flywheel. I will check tomorrow in the Onan book and get the right checking procedure and post it for you.
“A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty.” -Winston Churchill

Offline trapper

  • Senior Member x2
  • *****
  • Posts: 1645
  • Age: 76
  • Location: wis
  • Gender: Male
  • I'm new!
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #12 on: October 10, 2010, 10:48:45 PM »
Hilltop366  My small engine instructor in vocational school said the same thing but that was 35 years ago. A small mark on the flywheel key can throw off the timing on a lawn mower. 
stihl ms241cm ms261cm  echo 310 400 suzuki  log arch made by stepson several logrite tools woodmizer LT30

Offline r.man

  • Senior Member x2
  • *****
  • Posts: 2243
  • Age: 59
  • Location: Wilberforce Ontario Canada
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #13 on: October 10, 2010, 11:12:05 PM »
I tried to use two separate car coils on an onan motor a few years ago and couldn't get it to run right. Finally decided that the two coils were setting up some sort of feedback resonance or interference and ended up giving it back to my friend unfixed.
Life is too short or my list is too long, not sure which. Dec 2014

Offline Jeff

  • Fearless Leader
  • Administrator
  • *****
  • Posts: 49673
  • Age: 58
  • Location: Harrison MI
  • Gender: Male
  • I know that I do not know.
    • Share Post
    • THEE Forestry Forum
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #14 on: October 10, 2010, 11:25:11 PM »
I tried to use two separate car coils on an onan motor a few years ago and couldn't get it to run right. Finally decided that the two coils were setting up some sort of feedback resonance or interference and ended up giving it back to my friend unfixed.

Thats exactly what I was told would be the problem with twin coils. That's why I think bitsy4643's trouble could be the replacement coil was bad too, or its not the exact replacement required. I learned that not any old onan twin coil will do. Had that problem the year I got my mill. Coil was diagnosed as being bad, so I got one from another retired motor from Tammy's step day to try. He swore it was a good coil. Nothing. So I continued to look elsewhere, ut finally bit the bullet and bought the expensive onan replacement. Started as soon as I hit the key.   Makes sense that it fires with the twin coils, and also that it would not run on them.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life.
Ezekiel 22:30

Offline johnjbc

  • Senior Member
  • ****
  • Posts: 720
  • Age: 76
  • Location: Home Carlisle, Pa - Camp Fulton County, Pa
  • Gender: Male
  • Carlisle, Pa
    • Share Post
    • The Beaver Camp on Cumming Run
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #15 on: October 11, 2010, 09:27:52 AM »
Onan
Just went through a episode with my Onan starting last spring. It has always surged when idling but it started stalling on me. Took the top off the carburetor and found that water had built up and plugged up the small holes in the rod that extends down into the furl bowel. Used the smallest tip my welding tip cleaner to open them up and It got a little better.
The next time I tried to use it the motor wouldn’t start so I took it into Woodmizer and it took Marty about 5 minuets to find the coil was bad. The original coil is no longer available and the new one mounts in a bracket on top of the shroud. Took 3 tries to get the correct coil and bracket from Woodmizer’s Supplier, but they hung in there and got me what I needed.
Last week I needed to saw out some 4x4 Oak to build some shelving and the motor kept stalling. Cleaned the carburetor again but it didn’t help. Thought I would pull the plug wires to see if a plug might be breaking down. Pulled the first one and it slowed down just a little. When I pulled the second one it cut right out. Swapped the plugs but the trouble didn’t move.
Checked the compression and got 95 in one cylinder and 102 in the other witch should be ok. By that time it was getting dark and I noticed that occasionally a spark was jumping from the coil tower to the mounting bracket, about an inch. That night while reflecting on the problem I decided their must be high resistance in the high voltage circuit. Remember that Onan fires both plugs at the same time and the spark path is from the coil tower, out the wire to the first plug, across the plug, through the block to the second plug, where it jumps backward, then through the plug wire back to the other coil tower. Note the Onan coil is not ground internally like an automotive coil. You would have to use 2 automotive coils to replace it and that would double the load on your electronic ignition and risk burning it out.
The next morning I replaced a Plug wire. It ran much better but at idle it stumbled like the idle mixture screw was set wrong. I never could find an adjustment screw. I went through my Woodmizer Manual again and found one page on adjusting the carburetor, It showed one on the base of the carburetor under the muffler where you can’t see very well. Where the screw should be on mine there is a domed cover about 2 inches across. Decided to take the base off to see what was in there. It was fun getting it out. The bolts that hold the carburetor base on come up through the intake manifold so it has to come off, and the bolts that hold it on hit the exhaust before they are loose so that had to come off.
Inside the domed structure is a spring loaded diaphragm and under that there is a rubber flapper valve held in by a c-clip. I think the flapper valve may have been stuck as there was an impression of the hole it was sealing deformed into it. Turned it over and put it back together. Should try to find a carburetor kit.
While I  had things apart I saw that there was black RTV coming out of the joint between the 2 half’s of the intake manifold so I drilled out the rivets and resealed it just incase. Then I Pop Rivet it back together. I’m not sure what was the original problem and if I caused some of them but it now idles like a new born Kitten, better that it ever did!!!!
Hopefully this will give you some things to check.
John
LT40HDG24, Case VAC, Kubota L48, Case 580B, Cat 977H, Bobcat 773

Offline H60 Hawk Pilot

  • Senior Member
  • ****
  • Posts: 449
  • Age: 71
  • Location: Bonifay, FL and Huntingdon, PA
  • Gender: Male
    • Share Post
Re: Onan 24hp woodmizer mill will not start, please help
« Reply #16 on: October 12, 2010, 01:17:50 AM »
I read all the Recommended Check's and This Happened to Me (above).

I always check the spark jump and color. The Spark at least 3/4 to 1 inch and be Blue or Blue/ White color. Buy a Spark Checker from one the Auto Store's, about $ 7.00 bucks. Weak (low voltage) is Red/ Orange and will jump only 1/4 to 1/2 inches. What you don't see is that the high voltage spark is even harder to jump in a pressurize cyl. at 110 to 155 cyl. pressure. Also, make sure you have a good ground when testing spark output
 
Case 1150B & IHC TD-340 Dozer's, IHC 4WD 3800 & CAT 436B Hoe's, Franklin 170, Semi's: (1) Freightliner, (2) KW's, Marmon, Mack w/ Prentice Ldr., F-700 Crane Trk., (6) Mid Size Trk's. - Dumps, Flats, 1 Ton w/ 40 ft. 5th Whl. & (4) Semi Tlr's., LM 2000 Mill, (2) XL 12's., Solo 681, EFCO 152, Old Iron.


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

xx
Onan 24hp no start

Started by ARKANSAWYER on Sawmills and Milling

24 Replies
6791 Views
Last post February 17, 2006, 07:53:44 AM
by ARKANSAWYER
xx
sawing speed on an lt40 w 24hp onan

Started by paul case on Sawmills and Milling

51 Replies
6672 Views
Last post February 11, 2012, 01:35:56 PM
by customsawyer
xx
Need a muffler for my wood-mizer with the Onan 24hp

Started by VictorH on Wanted

16 Replies
6579 Views
Last post March 14, 2012, 08:10:44 PM
by woodmills1
xx
Woodmizer 1992 Onan 24xl acting up

Started by canadianwoodworks on Sawmills and Milling

13 Replies
2188 Views
Last post August 20, 2015, 08:10:20 PM
by Kbeitz
 


Powered by EzPortal