Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

Onan Compression


  • Please log in to reply
17 replies to this topic

#1 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted September 19, 2014 - 12:51 PM

I am only getting 70 and 75 lbs compression on my onan B43. That test was done cold as the engine is not running right now ( needs carb. work). Do I need to have it running and warmed up to get an accurate reading? The engine is removed from the tractor right now. I hate to put it all back if it needs a rebuild. 



#2 Auburn David OFFLINE  

Auburn David
  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 61865
  • 2,754 Thanks
  • 1,962 posts
  • Location: Alabama

Posted September 19, 2014 - 03:39 PM

I have seen folks online say 70-100 is good,I have never messed with an Onan..they say as long as thet are within 5psi of one another its all good.


  • Bud said thank you

#3 Cat385B ONLINE  

Cat385B

    Therapy CAT

  • Senior Member
  • Contributor
  • Member No: 8002
  • 11,756 Thanks
  • 8,924 posts
  • Location: MN

Posted September 19, 2014 - 03:55 PM

Onan specs 75-115 psi. How does it run? Smoke at startup? Use oil? When was the last time it was de-carboned?
  • Bud said thank you

#4 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted September 19, 2014 - 07:51 PM

It's new to me and I don't believe it has been run in around 3 or 4 years. I guess I will clean and put some new parts in the carb., reinstall the engine and see what happens. Both cylinders showed about 75lbs. give or take a pound or two. Thanks guys.



#5 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted September 20, 2014 - 06:43 AM

You don't have to reinstall it to run it. Might give you a better idea what's going on to run it some. You might want to add a little MMO (Marvel Mystery Oil) in the oil to help clean things up. Might even raise the compression some.


  • Bud said thank you

#6 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted September 20, 2014 - 07:37 AM

Just out of curiosity, did you check the compression with the cylinders dry? Or did you squirt some lube in there before you checked?


  • Bud said thank you

#7 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted September 27, 2014 - 01:37 PM

It was dry. I since have got it started and ran it for a moment not hooked up to anything yet. No smoke and ran good. Now I can't find a picture of hooking up the throttle as everything was gone springs, retainer clips,etc. got it all but the shorter govorner sping, maybe it doesn't use one?



#8 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted September 27, 2014 - 04:53 PM

I have a B43 on 'Big Bertha'. I'm sure it has a short spring between the cable and governor linkage. I'll see if I can get you some pics! Probably tomorrow, though.


  • Bud said thank you

#9 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted September 27, 2014 - 05:46 PM

Thanks Kenny here is what I have so far.  I am guessing it hooks in one of the four hole on the arm pointing to the right (top center of the photo at the right of the red spring) but what the other end hooks to I can't find anything.

Attached Thumbnails

  • IMGP2115.JPG


#10 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted September 27, 2014 - 06:05 PM

I'll have to look at mine tomorrow and figure this out.


  • Bud said thank you

#11 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted November 06, 2014 - 10:32 AM

Kenny, I was wondering if you knew anymore on the springs? If anyone else knows or has a picture of the governor springs. I don't even know if there are two springs or just one and where the second on goes? I can't find a picture that shows them.

#12 MH81 ONLINE  

MH81

    Proud to be Deplorable

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 802
  • 27,334 Thanks
  • 28,642 posts
  • Location: N. W. PA

Posted November 06, 2014 - 05:57 PM

I think I have a b43 in the gt19.9.
I will be near it tonight, if I can scare up enough light to get pics
  • Bud said thank you

#13 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted November 06, 2014 - 06:43 PM

Kenny, I was wondering if you knew anymore on the springs? If anyone else knows or has a picture of the governor springs. I don't even know if there are two springs or just one and where the second on goes? I can't find a picture that shows them.

Sorry! I spaced this right out. But you have your throttle cable hooked in different from mine. I was able to get out and get a pic, though not real clear.

Image040.jpg

 

My cable hooks to the other side and that is where the little spring is.


  • Bud said thank you

#14 Bud OFFLINE  

Bud

    Tractorholic

  • Senior Member
  • Contributor
  • Member No: 650
  • 341 Thanks
  • 404 posts
  • Location: Montana

Posted November 06, 2014 - 07:42 PM

 

Sorry! I spaced this right out. But you have your throttle cable hooked in different from mine. I was able to get out and get a pic, though not real clear.
attachicon.gifImage040.jpg
 
My cable hooks to the other side and that is where the little spring is.

 What tractor is this in? There are not all the heat sheilds and shrouds. I have to say the Onan b43 and the MF1655 is a nightmare to try and work on. I Have two carbs and countless hours and money put in and I still can't get it to stay running, no matter how the float is adjusted it iether starves or floods. That's why I wanted to make sure the springs were hooked up right. I guess I will have to give up and take to to someone who know the Onan.

#15 KennyP ONLINE  

KennyP

    FORDoholic

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 28,518 Thanks
  • 39,736 posts
  • Location: Collinsville, Oklahoma

Posted November 06, 2014 - 08:10 PM

Mine is a repower into an old Sears. Is yours a B43G or M? I have this pic of linkage for an M, but the G is very similar.

Onan Governor.jpeg

 

 


  • Bud and MH81 have said thanks




Top