Oil & Fuel 425 gas to diesel conversion?

[rs3]

Has anyone tried to convert a 425 mower to diesel using the 455 engine? If so how hard is it and what do you need to convert the mower other than the diesel engine. I currently have a 425 with 750 hours and it runs a little rough. It has been just sitting since last spring when I bought a x740. Since I bought the 740 I have been contemplating swapping the 425 to diesel. Any help would be appreciated.

 

[mfreund]

While it may be a neat project, I would suggest repair or replace the gas motor. Here is the reason. When you want or need to sell the 425 buyers will know right away it may be a cobbled up POS and stay away, I know I would. Even if it was professionally done with all JD parts the tractor is not how it came from the factory and will command less $ than a original. Some where some day someone will have to sell it. Even if only to the scrap man.

 

[rs3]

I am not really worried about resale. I was just wanting it as a spare mower to help mow. I don't want to put another gas engine in it. I just thought if anybody could help on this matter it would make it easier on me to make the decision to do it or not. I would think it would be easier to convert than to buy a 455.

 

[jd4310man]

I would have to say that the 400 series tractors are all the same except for the engines. I would say that the engine mounts are different and I would look to see if the drive shafts are the same length, the only difference in the wiring would be the addition of the glow plug circuit, and possibly a larger battery. I think that the deal maker with a swap like this how reasonable you can acquire the parts to make it work. Dealer parts are very expensive$$$. If you had a good used engine from a 455 and the necessary parts then I would say go for it.

 

[kennyd]

750 hours does not seem like much for that machine...I have a hard time believing it needs a new engine.

 

[TCowner]

Rs3, If you haven't been there already a good place to go for advice is Weekendfreedommachines.com. These guys are doing projects like that and usually can offer some helpful tips. Under forums use either the Restoration and Repair forum or the John Deere tractor and Late Model Garden Tractor Forum.

 

[etcallhome]

Maybe 750 hrs the engine shouldn't need replacing. I owned a 425 appx 7 yrs ago. JD replaced the engine and it only had appx 100hrs.
Sounds like a good switch to me if he can find a diesel at a fair price.
The savings alone just in fuel would make a big difference. I can mow almost twice as much with the 2305 compared to the 425.

 

[mfreund]

I would find out why the 425 is running rough before I yanked out the engine. I had a 322 and it burned out coils around 450 hrs. It had a coil for each cyl and were under $30 each. If that was the problem it would be cheaper than frankensteining the 425.

 

[pilot-werx]

There are very few mowers that I would trade my 455 for. It uses half of the fuel of my 445 and does not bog down. You will not regret the diesel.

 

[rs3]

The problem I had with the 425 is that it blew the porcelein out of the left sparkplug. I replaced the sparkplug and it has run a little rough ever since. It seems to have lost some power after the sparkplug blew out. After getting my x740 there is no comparison between the diesel and the gas. This project is just giving me something to do. I don't want to get rid of the mower, it is nice to have a second mower. My wife and I can be mowing at the same time and save each other a lot of time. We mow about 3 1/2-4 acres where we live. It takes alot more gas to run the mower than the diesel does. Diesel may be more expensive than gas but the diesel will out live the gas by far if taken care of properly.