Onans - to rebuild or not

[Eugen]

Hi gang, I have a bit of a dilemma. Let me explain. The tractors and engines I have at the moment are these:

Main tractor: 644. It came with a Kohler 14HP that seems to have been a John Deere edition. This engine doesn't smoke, feels strong and runs without a problem. Lacks the clutch but I had no thoughts of putting a mower deck on this one.

Previous main tractor: 446. This one has an Onan BF-MS which feels really strong, a beast with around 110 psi compression on both cylinders. Currently this is on snowcaster duty. However, I don't like this tractor because my clothes smell like exhaust after I use it. I've complained about it on the other site, and someone sent me a private message telling me that Onan engines are like that. Hard to believe right? But how can the very strong exhaust smell on me be explained, with strong compression and strong engine?

Tractor #3 is 224. This one has the K321 that I rebuild and runs awesome. This will be my mowing tractor I think.

Tractor #4 is a 444. My latest acquisition. All wheels need to be replaced, the TCV is stuck and probably needs to be replaced. Needs new seat, and painting. To my surprise the Kohler K321 on this machine is running like new. I'll probably make this the snowcaster tractor and sell the 446.

But!!! I have an Onan B43 engine that came with a parts tractor. The guy told me that it smoked badly when it was removed. Given that I've been so far happy with the Kohler 14HP, that I have plenty of, why would I want to rebuild the Onan 16HP? Is the large difference in price really worth it? Plus, will it still make my clothes stink even on a fresh rebuild?

What are your thoughts guys?

[ssmewing]

It will still make your clothes stink.

If you want an Onan that does not do that you would like a 4-digit model better. It is all about which way the engine cooling air is moving.

The Onan is a dirty engine and that is why they were discontinued. It is a wasted spark flat head. That means that for every stroke both pistons come to TDC. The cam only makes 1/2 a turn per crank full turn. The ignition fires on both sides but one of the two sides alternates having the exhaust valve cracked open. They burn about 2/3rds of the fuel that they use. The rest goes out of the exhaust. So, it is not burning oil that is the problem. It is a simple and robust design that as most things have, has trade-offs.

[DavidBarkey]

The newer OHV engines are more efficient with less fumes . But most of those these days do not have the torque to match the hp. I don't find the new engines have the same life expectancy as the older one as well due to minimizing the amount of metal used in construction . The other option is to switch it over to a diesel and run it on fryer oil . At least that way you will smell like fish and chips .

Dave

[Eugen]

I find that the Kohler 14 hp isn't stinking me up like that. Of course I like more ponies, so maybe I look for a k341? But that won't have the right fit or the clutch. If I'm going to deal with fitting complications I may as well go for a lot more power like 20 hp and up. There are times when I do garden work like plowing that I wouldn't mind significantly more ponies

Sure I'd like a diesel, Dave, but look at the prices of those and am not sure it's worth the difference.

One thing I'm considering is maybe put tall smoke stacks on the Onan. I'm surprised you guys with Onans aren't bothered by this.

[DavidBarkey]

I find that the Kohler 14 hp isn't stinking me up like that. Of course I like more ponies, so maybe I look for a k341? But that won't have the right fit or the clutch. If I'm going to deal with fitting complications I may as well go for a lot more power like 20 hp and up. There are times when I do garden work like plowing that I wouldn't mind significantly more ponies

Sure I'd like a diesel, Dave, but look at the prices of those and am not sure it's worth the difference.

One thing I'm considering is maybe put tall smoke stacks on the Onan. I'm surprised you guys with Onans aren't bothered by this.

What like this .

Nope never thought of it .

Dave

[Eugen]

Taller Dave, much much taller! I had something like what you have on Frankie on the 226 that I sold (B43 Onan two smoke stacks), and still didn't like the gases, because the stacks were still at the level of the head of the driver.

What a good looking tractor that 226 was, I should not have sold it

[DavidBarkey]

Taller Dave, much much taller! I had something like what you have on Frankie on the 226 that I sold (B43 Onan two smoke stacks), and still didn't like the gases, because the stacks were still at the level of the head of the driver.

What a good looking tractor that 226 was, I should not have sold it

Duck ....

Dave

[Seabee]

I have had Kohler's in my 444 and 224 tractor's. Never noticed the smell. I now have all Onan's and they smell! But I like them better, they run so much smoother than the Kohler's. They are both good engines, so it is hard to go wrong with them.

Bill

[Chad]

The newer OHV engines are more efficient with less fumes . But most of those these days do not have the torque to match the hp. I don't find the new engines have the same life expectancy as the older one as well due to minimizing the amount of metal used in construction . The other option is to switch it over to a diesel and run it on fryer oil . At least that way you will smell like fish and chips .

Dave

Hilarious Dave!

Eugen, have you noticed any difference with exhaust depending on the attachment? On my 444's I do find that I smell like exhaust with the blade on, probably because the exhaust blows against the blade and back at me (and driving forward only increases this). When mowing it's a lot less problematic, hardly noticeable.

My only Onan experience was with the P220G that was in my Wheel Horse 520h. No exhaust smell on that one, but she was thirsty!

Sent from my Pixel 4a using Tapatalk

[Eugen]

Chad, no matter what attachments I used with my Kohlers, my clothes hardly smell like exhaust. With the 446 Onan I've even had to take a shower after doing the lawn. And no significant smoke can be seen, as I said, it's not burning oil. On the contrary, might be running somewhat rich.