Generators and Electric Motors
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators. When asking new questions about your generator, ALWAYS give your model number AND serial number.

Onan Generators

1978 Ford Skid-Steer with Onan NHC engine will not start!


this thread has 7 replies and has been viewed 7227 times

Reply
 
Thread Tools Display Modes
  #1  
Old 03-25-2011, 04:50:07 PM
Merc300SD Merc300SD is offline
Registered
 
Join Date: Oct 2007
Location: Cumming Ga
Posts: 29
Thanks: 4
Thanked 0 Times in 0 Posts
Unhappy 1978 Ford Skid-Steer with Onan NHC engine will not start!

This engine powers a 1978 Ford Skid-steer. When purchased, it ran pretty well with a few performance problems. Since that time it died hard. I have had to replace the head gaskets (head nuts were very loose), intake gaskets, exhaust gaskets and a new carburetor. Valves are adjusted to specifications. Also replaced were the plugs, a new coil (developed no spark syndrome) and the starter went bad (shorted internally)! It will not start no matter what I have tried, even ether! There is now spark, the carb is new and set to factory specs, engine gets gas to the carb and cylinders, points are set correctly, it tries to fire but doesn’t quite get there. There is a little smoke while it is cranking and the plugs have a small amount of fluffy carbon on them after a few tries. I did a compression test and came up with 60 psi in each cylinder, spec calls for 100 psi. This may the cause of why it won’t start? Opinions? The only thing this engine has not had are new rings. The previous owned put in new bearings and seals. There is great suction on the intake pipe to the carb and good pressure out the muffler. Ideas?????
Reply With Quote
Sponsored Links
  #2  
Old 03-25-2011, 05:47:32 PM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Moderator
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 18,927
Thanks: 10,001
Thanked 16,802 Times in 7,774 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

You have found your problem. Low compression can make an engine hard to start. In case you don't know. Never take the oil filler cap while running or turning over the engine. Oil kinda blows out when you do.
Reply With Quote
The Following User Says Thank You to Billy J Shafer For This Post:
  #3  
Old 03-25-2011, 07:19:38 PM
Merc300SD Merc300SD is offline
Registered
 
Join Date: Oct 2007
Location: Cumming Ga
Posts: 29
Thanks: 4
Thanked 0 Times in 0 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

I would have to assume you are correct. As an experiment, I took my air hose with 100 psi with an adapter and pressurized the intake while cranking it. Still didnt start. I could feel the intake hose build up pressure so I know the cylinder was filled with that pressure when it came up on the intake.

Ill remember not to open the oil filler cap and crank it.
Reply With Quote
  #4  
Old 03-25-2011, 11:14:52 PM
marlorup marlorup is offline
Registered
 
Join Date: Oct 2009
Location: Kewaskum, Wisconsin, USA.
Posts: 38
Thanks: 201
Thanked 14 Times in 13 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

Just a quick thought. I agree with the low compression idea. But something I don't think you mentioned was the timing. You have spark and fuel, but is the spark getting to the cylinders at the right time. My 2 cents. Thanks, Mark.
Reply With Quote
The Following User Says Thank You to marlorup For This Post:
  #5  
Old 03-26-2011, 07:16:33 AM
wilson Ross wilson Ross is offline
Registered
 
Join Date: Nov 2008
Location: Glenwood Mn. USA
Posts: 73
Thanks: 0
Thanked 19 Times in 12 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

Quote:
Originally Posted by marlorup View Post
Just a quick thought. I agree with the low compression idea. But something I don't think you mentioned was the timing. You have spark and fuel, but is the spark getting to the cylinders at the right time. My 2 cents. Thanks, Mark.
Real easy to check timing would be a guess of mine.
Reply With Quote
The Following User Says Thank You to wilson Ross For This Post:
  #6  
Old 03-26-2011, 08:36:06 AM
Merc300SD Merc300SD is offline
Registered
 
Join Date: Oct 2007
Location: Cumming Ga
Posts: 29
Thanks: 4
Thanked 0 Times in 0 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

Timing is another factor I have considered. According to the manual, timing is preset at the factory. You can advance or retard the ignition via the points a degree or two but that is it. Not enough to affect starting. I tried changing the points gap, same results. To get to the front of the engine for the timing marks, the hydraulic cooler that is in front of the shroud and must be removed. Oil goes all over the place.... still something to consider. Not much access room to do much.
Reply With Quote
  #7  
Old 03-26-2011, 10:16:35 AM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Moderator
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 18,927
Thanks: 10,001
Thanked 16,802 Times in 7,774 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

Timing can be a problem. But on most of the two cylinder Onan engines. When you set the point gap you are also setting the timing. You can change it by moving the point box,but I don't think it will change that much.

Good point Mark. You need to cover everything when trouble shooting .
Reply With Quote
The Following User Says Thank You to Billy J Shafer For This Post:
  #8  
Old 03-26-2011, 11:18:03 AM
Merc300SD Merc300SD is offline
Registered
 
Join Date: Oct 2007
Location: Cumming Ga
Posts: 29
Thanks: 4
Thanked 0 Times in 0 Posts
Default Re: 1978 Ford Skid-Steer with Onan NHC engine will not start!

Quote:
Originally Posted by Billy J Shafer View Post
Timing can be a problem. But on most of the two cylinder Onan engines. When you set the point gap you are also setting the timing. You can change it by moving the point box,but I don't think it will change that much.

Good point Mark. You need to cover everything when trouble shooting .

It made no difference in starting. Anyway, does anyone have a NHC shortblock that needs a rebuild? Running condition would be better.
Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Onan MDJA Wiring Diagram (4/25/1978 version) RossJo Onan Generators 3 12-23-2011 09:35:31 AM
Help me with a hard to Steer Ford 2000 DTurner Antique Farm Tractors 2 06-21-2010 09:23:15 PM
Onan 300CI Ford Engine Cruiser Multi-Cylinder Stationary Gasoline Engines and Power Units 2 02-18-2010 01:05:51 AM
Skid steer loader ID Greg Shipley Farm Antiques and Collectibles 2 11-15-2007 05:23:51 AM
skid steer Greg Shipley Garden Tractors and Mowers 0 05-21-2007 11:26:47 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 04:44:53 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277