Generators and Motors
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 4.0 BGE fuel pump/ignition problems


this thread has 9 replies and has been viewed 370 times

Reply
 
Thread Tools Display Modes
  #1  
Old 11-16-2017, 01:57:49 PM
JNRMoto JNRMoto is offline
Registered
 
Join Date: Nov 2017
Location: Sandstone, Minnesota
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default Onan 4.0 BGE fuel pump/ignition problems

Onan 4.0 BGE-IR/26100E SN/1870922125. I just purchased in non-running cond. (with a bucket of removed parts) and have put it back together. Installed new points & condenser, replaced plug wires, cleaned all connections inside control panel, spark was excellent. Cleaned carb, installed new generic fuel pump. Hot wired pump to fill the new fuel filter, and tried to start, no spark. I unplugged the fuel pump to run further tests, spark was excellent. With the pump unplugged the engine starts and runs until fuel is used up in carb. The control board is the newer design #300-2784-01 (no voltage regulator in the cabinet) same as the Emerald Plus.
Any ideas where to go from here? Thank You!
Reply With Quote
Sponsored Links
  #2  
Old 11-17-2017, 11:28:06 AM
Kevin K Kevin K is offline
Registered-III
 
Join Date: Jan 2005
Location: upstate New York USA
Posts: 3,555
Thanks: 3,203
Thanked 3,580 Times in 1,928 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Stop by the Twinslan site and download the following manuals:

965-0130 operator
965-0232 parts
965-0530 service
965-0630 install
900-0186 wiring diagrams

The wiring diagram for your generator in 611-1174 on page 76 of the wiring diagrams manual.

The 611-1174 wiring diagram shows the fuel pump is in parallel with the ignition coil. Both should be energized at the same time. You might want to check the fuel pump for excessive current draw. Then check the A1-P1 connector for a bad contact.
Reply With Quote
  #3  
Old 11-17-2017, 10:30:29 PM
JNRMoto JNRMoto is offline
Registered
 
Join Date: Nov 2017
Location: Sandstone, Minnesota
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Thanks Kevin for all the info. I checked the voltage at the fuel pump when cranking - 12.1 and the coil was 3.5. Disconnected pump and voltage went up to 8.5 at the coil and engine started. I'll recheck connections and run a few more tests and will let you know what happens.
Reply With Quote
  #4  
Old 11-18-2017, 02:32:14 PM
JNRMoto JNRMoto is offline
Registered
 
Join Date: Nov 2017
Location: Sandstone, Minnesota
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

I cleaned contacts again and tested resistance from the connections to the pump and coil. With board connected A1-P1 wire shows 7.5 and the A1-P2 is 4.3. When I disconnected the board and tested the A1-P1 dropped to 4.5 ohms. A1-P2 4.3. Cleaned connections and no change. After reading through several hours of postings on this subject I decided to order a new board from Flight Systems, being 30 years old it's probably due. Will post results in a few days. Thanks again for your help.
Reply With Quote
  #5  
Old 11-19-2017, 02:07:38 PM
Jim Marcozzi Jim Marcozzi is offline
Registered-I
 
Join Date: Nov 2013
Location: Hempfield, PA, USA
Posts: 472
Thanks: 48
Thanked 253 Times in 137 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Install a separate fuel pump relay that's triggered by any "start-run" circuit.
Provide power to the relay's B+ contact directly from the starter solenoid's B+ input lead and fuse it for the correct pump load.

You're creating too much voltage drop to the IGN system with the load of the pump, wherever you're powering it from.
Reply With Quote
  #6  
Old 11-19-2017, 02:25:21 PM
len k len k is online now
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 14,938
Thanks: 390
Thanked 5,409 Times in 3,930 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Seen a control board with bad relay contacts. Added relay will be a band-aid, better to find the underlying problem as it may get worse and not have enough voltage to even run the spark coil.

Last edited by len k; 11-19-2017 at 03:42:14 PM.
Reply With Quote
  #7  
Old 11-21-2017, 03:57:53 PM
JNRMoto JNRMoto is offline
Registered
 
Join Date: Nov 2017
Location: Sandstone, Minnesota
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Thanks for the responses!
I installed a new board from Flight Systems and same thing. I called one of their techs and he said he has never heard of this problem, but speaking to him gave me an idea to run a jumper wire from the + side of the coil and plug it into the fuel pump. Engine started and ran great. I let it run for 15 minutes and adjusted the idle mixture, checked the choke pull off, stat, etc., etc. I have concerns if I leave it that way permanently it may create other problems. Does anyone know if current for the fuel pump wire comes from under the generator housing? Thanks again for any assistance.
Reply With Quote
  #8  
Old 11-21-2017, 04:11:08 PM
len k len k is online now
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 14,938
Thanks: 390
Thanked 5,409 Times in 3,930 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Sounds like you have a bad connection or bad wire somewhere. Shake the wire and see if it's intermittent. Starting to remember Yoda saying some wires had broke copper under their insulation. Vibration maybe?

Think I saw in schematic there's a diode in fuel power lead somewhere, check it and if it's connection is corroded.
Reply With Quote
  #9  
Old 12-04-2017, 06:23:56 PM
JNRMoto JNRMoto is offline
Registered
 
Join Date: Nov 2017
Location: Sandstone, Minnesota
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

Finally got time to get back to it. After checking voltage output at brushes (16vdc) decided to replace brushes as one was longer than other. I did not have an armature stone, remover spark plugs, used allen wrench to turn, then a very fine emery cloth on my finger tip, blew off dust, then sprayed with contact cleaner. Voltage went up to 17vdc. Raised speed up a little and voltage went to 18.0 (minimum spec) Then put under load 28.5 vdc and will run drill press and large electric fan and light bulb at 120ac. The voltage at the coil and the fuel pump wire now reads 17v so it may run the pump also. Will try tomorrow. It is close!

The only question I have is what is the correct Champion plug for the BGE 4.0 IR/26100E? Can't find any # in the owners or service manual. I believe the plugs sent to me may be wrong. (Champion RS17YK) Thanks for all the assistance in getting this old beast going! You guys are GREAT!
Reply With Quote
  #10  
Old 12-04-2017, 07:40:02 PM
len k len k is online now
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 14,938
Thanks: 390
Thanked 5,409 Times in 3,930 Posts
Default Re: Onan 4.0 BGE fuel pump/ignition problems

17VDC at fuel pump sounds too high, I suspect your rpm (hz) are too high. Your bat won't last long being charged at 17VDC, it'll cook.

I'ld get engine to make ~ 62 hz at no-load then take a no-load voltage measurment on 120VAC line. Pfd page 94 says votlage at 62 hz no-load should be 127.5 VAC +- 4.5 V. Most people here use a ~$20 kill-a-watt meter for hz and voltage ( ebay or home depot)


If it's very low then with engine off, brush leads removed, I'ld measure rotor resistance, should be 7.62 ohms +10% and ~ infinity (> ~ 1,000,000 ohms) to the frame. Then check diode bridge CR4

Last edited by len k; 12-04-2017 at 07:52:24 PM.
Reply With Quote
Reply


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 4CCK Ignition Coil 6v to 12v and Fuel Pump? DuaTJC Onan Generators 20 11-17-2014 05:40:18 PM
Onan Marquis 5000 BGM fuel pump problems budman Onan Generators 4 06-14-2011 07:53:02 PM
Fuel Pump Problems jhhowell Onan Generators 13 11-14-2008 09:27:29 PM
IHC M Fuel Pump problems TomFG Antique Gas Engine Discussion 11 05-28-2005 11:21:07 PM
Fuel Pump Problems? Bill Blackburn Antique Engine Archives 5 05-28-2003 10:26:08 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 08:22:42 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 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277