Jump to content

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



Photo
- - - - -

Onan B43G to a P218 engine swap on a 318


  • Please log in to reply
5 replies to this topic

#1 DixieViper OFFLINE  

DixieViper

    New Member

  • New Member
  • Member No: 2725
  • 0 Thanks
  • 4 posts

Posted April 17, 2011 - 01:21 PM

Good afternoon to all,

I'm new to the site and am a proud John Deere owner of a 655 and more recently a 318. Thus far this site is a great resource and I'm happy to have found it.

The 318 that I own is mechanically solid other than the engine, one of the most important parts of course. It runs stong, but burns some oil and smokes a little. I'm not sure if this is a ring, gasket, or valve issue. Just haven't had the opportunity to tear into it yet. I bought it knowing that I would have to put a little TLC into it and am fine with that cause I want to keep it.

I have the opportunity to exchange the B43G motor in it for a good condition Onan P218 engine that runs great. Does anyone know if there are any compatibility issues with this? Is it as simple as disconecting the mounting bolts, drive shafts, hoses, lines, etc.... and taking one out and putting the other in in its place and reconnecting everything? I know I will have to buy a new starter for it as the old one on the B43G won't mate properly, but other than that I'm not sure and don't want to buy something that I can not use. Any advice or thoughts that I'm not addressing would be welcomed.

Thanks,

Jason

#2 NUTNDUN OFFLINE  

NUTNDUN

    Lost in Cyber Space

  • Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 3
  • 10,266 Thanks
  • 15,618 posts
  • Location: Pennsylvania

Posted April 17, 2011 - 04:57 PM

I don't know why the system flagged your post as moderated but I approved it.

Anyway, I am far from a resident expert on the Onans and I am sure other guys will be able to give you a more definitive answer. With that said it should pretty much be a straight swap. The parts that you will probably run in to trouble is going to be the throttle and choke cables with the linkages being in a different spot. If you have to you can get new cables pretty cheap. The wiring may be a little different too since the Performer series is electronic ignition. If it isn't a horsepower increase switching to the performer I would probably stay with the one you have. Parts are a little cheaper and you don't have the costly electronic ignition if it goes south.

The other thing to check if it is burning oil is to clean the crankcase breather and make sure the reed valve is in good shape. We have service manuals on the site and it shows how to clean the breather.
  • DixieViper said thank you

#3 DixieViper OFFLINE  

DixieViper

    New Member

  • New Member
  • Member No: 2725
  • 0 Thanks
  • 4 posts

Posted April 17, 2011 - 08:39 PM

Nutndun,

Thanks for the advice. I'll look into the crankcase breather and the reed valve in the morning to see what kind of condition they are in. I also downloaded a couple of the manuals that I think will be helpful. I'll let ya'll know how it goes.

Jason

#4 NUTNDUN OFFLINE  

NUTNDUN

    Lost in Cyber Space

  • Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 3
  • 10,266 Thanks
  • 15,618 posts
  • Location: Pennsylvania

Posted April 19, 2011 - 02:45 PM

Jason, let us know how you make out.

#5 DixieViper OFFLINE  

DixieViper

    New Member

  • New Member
  • Member No: 2725
  • 0 Thanks
  • 4 posts

Posted April 19, 2011 - 07:11 PM

Nutndun,

I have found out that I will have to replace three things if I make the swap from the B43G to the P218. First the drive shaft for the B43G, part (M85491 or AM39150) has to be changed for the P218 to part (AM102988). The drive shaft for the P218 is about 2 inches longer approximately. Second and third the throttle and choke cables will have to be replaced with parts (AM100130 and AM105000) for the P218 to be compatible. I found this information at the link below if you type in the model of the tractor and look up the corresponding part:
John Deere - Parts Catalog

My other question is since the B43G is a points and condensor engine and the P218 is electronic ignintion, will the existing electrical wiring be compatible to plug into without making any modifications???? If anyone knows anything about this please let me know. This is really my only concern now. I feel confident that I can navigate the other issues farily well.

Jason

#6 NUTNDUN OFFLINE  

NUTNDUN

    Lost in Cyber Space

  • Admin
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 3
  • 10,266 Thanks
  • 15,618 posts
  • Location: Pennsylvania

Posted April 19, 2011 - 07:18 PM

Nutndun,

I have found out that I will have to replace three things if I make the swap from the B43G to the P218. First the drive shaft for the B43G, part (M85491 or AM39150) has to be changed for the P218 to part (AM102988). The drive shaft for the P218 is about 2 inches longer approximately. Second and third the throttle and choke cables will have to be replaced with parts (AM100130 and AM105000) for the P218 to be compatible. I found this information at the link below if you type in the model of the tractor and look up the corresponding part:
John Deere - Parts Catalog

My other question is since the B43G is a points and condensor engine and the P218 is electronic ignintion, will the existing electrical wiring be compatible to plug into without making any modifications???? If anyone knows anything about this please let me know. This is really my only concern now. I feel confident that I can navigate the other issues farily well.

Jason


The wiring would have to be done a little differently but not much if at all. I just recently did a swap on my Massey 1655. It had an Onan B48 in it with the points ignition. I put the Onan P220 in it that I had. The difference with mine was the voltage regulator was mounted in a different spot and I had to rerun new wires for that. I would imagine the B43 will use the positive side to the coil for the kill switch. If that is the case then the P218 should wire right up, might have to run new wire or add wire where needed. Just make sure you use good connectors when you do your wiring. I only use the shrink wrap/weatherproof connectors. Soldering splices and using shrink wrap to cover the splice is good too.




Top