PT422 Engine shaking / sputtering

[woodlandfarms]

Do you even use your PT? those are the cleanest 425 pictures I have seen except for someone who has a new baby rolled off the back of a delivery truck.

Great job on the mod. You have a bunch of 425 owners very very excited. Wonder if this should all go into a new thread for easy searching.

Carl

 

[Vacuous_One]

J_J: Thought about that...but, my P/T is an older model. With the later 425 models being "beefed" up, I don't think it's fair to call a 422 with a bigger engine a 428. Honestly, I don't know what would be fair!

woodlandfarms: Yes, we do use it. It's just that those photos were taken right after I changed out the engine. And, since I had the engine out...I tore it all down and repainted it. So, it's repainted and unused in those photos! I promise it doesn't look like that anymore, though! :laughing:

 

[BobRip]

Beautiful! This is the way to upgrade. Can you give us part numbers and suppliers for any parts you added. Like the fitting for the return gas line.

 

[Vacuous_One]

BobRip,

Yes, I can...but it will take a while! Thought I had that all nice & organized, but...I can't find it all!

I'll have to do a little searching and organizing before answering!

 

[ponytug]

This looks like a fantastic job! It looks like a great solution to a chronic problem for many people. I hope it returns many years of service.

Does your return hose go to the bottom of the gas tank? If not, I have a small heads up. If you get foaming (aeration) issues in warm weather (similar to vapor lock), you might want to consider adding a hose in the tank to get the return submerged. (I don't know how much fuel the Robbins recycle to the tank and at what rate, but I know it is a general concern for fuel injection returns in cars.)

It may be totally irrelevant here...

The close clearance on the dipstick looks like it would be easy to fix with a vise on the mounting brackets.

All the best,

Peter

 

[Vacuous_One]

ponytug: No, the return doesn't go to the bottom of the tank. It stops just inside the top of the tank. Haven't run into any issues yet, but thanks for the heads-up...I'll keep it in mind if I do!

Parts used in the modifications are per the attached files. I replaced the coupling for the wheel drive on the front end of the motor and both spiders (due to wear/damage...not because of any issue with the new motor), added the grommet and "L" fitting for the fuel injection return line, and - thanks to this forum - been able to identify and replace the fan switch.

If I think of anything else, I'll let you know...

 

[Marks481]

I'd negotiate with P/T to pay the difference and upgrade to the fuel injected engine on any new machine!

Good thought. That would definitely be a worthwhile option for a customer to think about. The difference between the new 25 and 28HP engine is only about $700.

Of course, from Power Trac's perspective, it blurs the lines between the models they offer. Having such an option available might convince a PT1430 shopper to go the cheaper route (a "PT428"). That would mean a lot less $$$ in both tractor and attachments. I know a 28 hp air cooled engine is not really in the same ballpark as a 30 hp diesel engine, but not everyone would see it that way.

Thanks for the pictures and model numbers. I know alot of us will be looking for reports on your engine over the next couple of years. It is nice to have a clearly defined path to follow when we have to upgrade.

 

[Clumber]

Good thought. That would definitely be a worthwhile option for a customer to think about. The difference between the new 25 and 28HP engine is only about $700.

Of course, from Power Trac's perspective, it blurs the lines between the models they offer. Having such an option available might convince a PT1430 shopper to go the cheaper route (a "PT428"). That would mean a lot less $$$ in both tractor and attachments. I know a 28 hp air cooled engine is not really in the same ballpark as a 30 hp diesel engine, but not everyone would see it that way.

Thanks for the pictures and model numbers. I know alot of us will be looking for reports on your engine over the next couple of years. It is nice to have a clearly defined path to follow when we have to upgrade.

I just bought a PT 425. Is swapping the engine really possible? There is no mention of this on there site.

Patrick

 

[Marks481]

Power Trac on occasion customized their product for customers, such as installing different capacity wheel motors.

I suspect that their willingness to entertain requests is very dependant on the the economy and how many orders they have received recently. Sometimes they categorically refuse anything like this, other times they agree.

The last time somone (as reported on this forum) asked for a different engine, they refused. I suspect that usually they will not agree to the alternate engine, even if it is a drop-in replacement. They would prefer you buy the PT1430 if you want more hp. And pay significantly more for the attachments.

Consider this: if you really want to replace your EH72 25 hp with the 28 hp version, you can probably ebay your new engine for $1000-1100.

Maybe they haven't loaded up the truck yet... call Terry and ask him.

 

[coolconnection]

I wonder how much a fuel injection kit would cost to upgrade the 25 horse robin engine. Do you think it is doable and a worthwile upgrade or do you think it is just for new engines?

Just wondering:anyone: