Harbor Freight into a PT422

[Phils]

I suddenly needed an engine, quickly and cheaply. Harbor Freight has 22hp Predator engines for $700. Because of the muffler, and a crankshaft shoulder that adds 3/4" to the engine/pump assembly, I had to move the gas tank out of the engine compartment, so there was another $200. With all the hardware/pieces/parts/taxes, the total came in barely above a grand. I doubt I'd have gotten parts to rebuild the Robin for that amount.

It took me three weeks, but most of that time was waiting for the tank and a 1" ID Lovejoy connector ($24 Ebay -- the Subaru has a 1 1/4" crank).

The choke is mounted on the engine, as is the ignition switch. I tried to keep everything simple, simpler than before. I may or may not move the switch to the dash in the future, it isn't really a problem like it is. I mounted the throttle to the engine cover within easy reach of the operator. It's attached with wing nuts so it detaches easily when I want to raise the "hood".

I removed both side screens, both to access the engine controls and also to reduce heat. The side benefit is that most maintenance can be done without lifting the cover. Since the gas is filled without lifting the cover either, it will only be necessary for it to come up for cleaning and changing the hydraulic filter.

This muffler is quieter than the stock PT "muffler", it should go without saying. I'm still 'reaching' for the ignition switch by the steering wheel, but either I'll get used to it or I'll move the switch. The engine runs much cooler than the Robin, no run-on or pre-ignition, which I'm sure is a result of that ******* exhaust design of PT.



Phil

 

[MossRoad]

Well done! :thumbsup:

I'd suggest putting some sort of latch to hold the hood down in case you catch the gas tank or more-open-now-than-before hood on a low branch or something.

 

[Phils]

Good suggestion, MR.

Of course, the hood wouldn't be able to go any higher than hitting the seat, maybe 4"?

Now that the machine is operational again, I can spend some time on details like that. I'd thought about a short detachable cable, not for the reason you mentioned but because I've thrice tried to lift the hood without disconnecting the throttle.

On hindsight now, I should have removed the side screening long ago. What's it there for, anyway? The engine bay is staying cooler and the motor has better access.

Phil

 

[MossRoad]

I need my screens for the brush that I go through. I get all cut and scratched up sometimes. I'm sure I'd hook that external throttle on a branch or brambles.

A lot of people are saying good things about those predator engines. Hope it works out well.

 

[woodlandfarms]

very well done.. We have a Chonda engine from HF on a rota tiller and it works great.

My notes would be initially keep an eye on your hood hinge and retention arm, the added stress of 70lbs of fuel on a hinge might be noticeable. also not sold on the fuel lines, they look like they might get too warm and vapor lock but hard to tell.

 

[Phils]

Thanks, Carl.

As sturdy as the machine is constructed, I don't expect the additional 50 pounds max to cause any undue stress. It's a 4 gallon tank that weighs 4 pounds. It was the best fit for the top of the hood I could find (8" x 20"). The fuel hose runs alongside the hydraulic cooling hoses and they've never had a problem with heat, even with the old configuration by Tazwell that seemed to retain all the heat possible in the tub.

My evolving plan was to eliminate the engine cover altogether. I just had to find a place to mount the oil cooler assy and a gas tank. I couldn't.

I knew from the outset that the exhaust would be the biggest problem. I contacted muffler shops and discussed bending and forming a tubing exhaust with a small muffler like I've seen here (a long time ago).

A friend had, years ago, planned on mounting a generator in a shed and modifying the exhaust piping to be outside the shed. When he called the gen manufacturer for suggestions, they told him in no uncertain terms how much the exhaust design does as far as removing heat and that in incorrectly designed exhaust could easily cause the engine to run too hot. Then I showed him PT's exhaust "system", and described how hot the PT runs and the run-on, etc., and said it couldn't get much worse with pipes I designed. After a week of thought, I decided to retain the stock muffler and eliminate the engine cover.

I put a "Chonda" engine (thanks, Carl, that's funny) on a woodsplitter a couple of years ago and I'm VERY satisfied with it. The reviews for this 22hp engine were over 450 positive and NO negative.

I also felt that only 540 hours on the Robin engine was too young for replacement until I read a few posts here of these engines going down with barely over a hundred hours. My motor was getting tired, but a bad combination of circumstances ended it's life in a moment. I have no complaints about that, tho, since it popped and died just as I parked it in it's place in a carport (well, "tractorport", actually. It DIDN'T quit 1/4 mile off into the forest inaccessible by my truck. It DIDN'T die while up at my friends house.... he was using it there for 2 weeks. It DIDN'T go FUBAR as I was shoving huge piles of brush into a giant raging bonfire but waited until about 2 minutes later. If it had died then, I'd be getting an entirely new PT, less my insurance deductible. Living in a brushfire area of California, tho, I'm reluctant to have any insurance adjuster nosing around after a claim because it's too hard to even GET coverage in this area.

It may be too soon to verify 100% until our daily weather temps run in three digits this summer, but so far heat-related problems are gone. Predator Trac went to a lot of effort to retain the original exhaust setup and gas tank location and he did a beautiful job. I wanted something better than stock, when all the work was done. Cooler is better.

Phil

 

[PTWannaHave]

What a reasonably-priced, elegant solution!!

Looks like fuel delivery is gravity-fed?

Looks like accessing the hyd. filter will be a lot easier now...

 

[Phils]

What a reasonably-priced, elegant solution!!

Looks like fuel delivery is gravity-fed?

Looks like accessing the hyd. filter will be a lot easier now...

Yes on all three points, PTWH!

Now I'm getting into the "hindsight" moments. Like: why the heck didn't I remove those side screens long ago? I no longer need the electric fuel pump (to stop the vapor-lock I experienced years ago. This is simpler, runs cooler, and has better engine access than before.

What's the capacity of the stock fuel tank? I was thinking about 3 or 4 gallons, but I never measured. This new tank is 4 gal but I don't know if I gained or lost tank capacity.

IF my Robin engine was still working, and knowing what I know now, I'd remove those screens immediately just for the better airflow/cooling. Even if a branch or twig "poked" into that area, it shouldn't hurt anything anyway. I didn't remove the rear screen because it seems to add structural stability to the entire cover, unlike the side vents.

Phil

 

[MossRoad]

My 2001 model year PT4215 has a 5 gallon plastic tank under the hood. If I put more than 4 gallons in it, it splashes through the gasket around the filler cap anyway, so at least for me, it only 4 gallon usable capacity. That gives me almost exactly 4 hours on the tractor before I run out of fuel, so by then, I need a sandwich anyway!

 

[Phils]

My 2001 model year PT4215 has a 5 gallon plastic tank under the hood. If I put more than 4 gallons in it, it splashes through the gasket around the filler cap anyway, so at least for me, it only 4 gallon usable capacity. That gives me almost exactly 4 hours on the tractor before I run out of fuel, so by then, I need a sandwich anyway!

Thank, Lichen Lane! I'd never measured the capacity. And since the only other choice I could find was for a 10" diameter that would've held more but been much bigger. I figured 4 gallons would be sufficient, at the worst I'd be filling more often --- which isn't that big of a deal. Yep, sandwich or beer break while the machine cools down before refueling.

On another note, I got to mow land that I haven't had to mow for 4 years. El Nino has come through! We've gotten more rain in the last couple of months than we've gotten in the last few years. Our area is ALMOST out of the "severe" drought designation! And it may rain again next week! I know.... you are thinking "BIG DEAL!" Well, I can say YES, it's a big deal WOO HOO!!!

I don't suppose any forum members need a used gas tank, heat shield and "exhaust pipe"?

Phil

 

[MossRoad]

Oh, I understand about the drought. That's gotta be tough. May you have gentle, long lasting rains with breaks so it soaks in VS run-off and mud.

I gotta say, we take our water for granted here in northern Indiana. It's never more than 40' down and its everywhere! The great lakes and Mississippi watersheds overlap here in South Bend, IN. Its a continental divide, of sorts. Surface water either goes to the gulf of Mexico or the north Atlantic. You wouldn't think that in Indiana, but that's where it all goes.

Anything in purple goes to lake Michigan. Pink goes to lake Erie. Both of those go north and east. Everything else (yellow, green, gray) ends up in the Mississippi.

 

[farm boy00]

That's good to you that's it's helping. Here screwed up winter, only had half the snow needed (im a plower) and has been muddy and a slop hole on our farm with 3x the rain we get usually.

 

[5030]

That HF engine is a Lifan FYI. I'm about to get one to repower my gas Bobcat that has a Kohler twin with a serious rod knock.... I've bought three others so far, a 6 horse for my pressure washer (that had a Briggs that puked), a tiny 79 cc one (smallest and cheapest Pred you can buy) for my Troy-Bilt Pony cultivator tiller to replace a smog producing Tecumseh (burned as much oil as gas) and finally a 6 horse for my 2 year old Rear Tine MTD tiller than came with a Hoinda that was a piece of junk (not the tiller, the Honda).

All have been flawless. The only odd thing I found with the 6 horse engines is, if you fill the gas tank to the very top, they will sputter a bit, other than that, they all start 2 pulls, don't eat oil and are miserly on gas...and don't run on either....

 

[Phils]

An update:

As anticipated, I moved the ignition switch to the dash. I used the HF switch as it seems heavier duty than the stock PT one.

I like the choke and throttle where they now are. I was having problems with the LONG stock cables and both were overdue to be replaced or cleaned and lubed.

With a better muffler, I was hearing noise from the engine cover rattling. I slipped two vinyl grommets over the rear hinge pins, making a tighter fit, and the noise disappeared.

I did some extended mowing and the engine runs MUCH cooler than the Robin. Mostly that's due to a better designed exhaust, I'm sure, but not having the side screens must help too. MOST "real tractors" are designed the same way with the motor accessible and just covered by a hood.

On hindsight, I should have removed those side screens long ago. Besides better cooling and airflow, not having to tilt the hood to check oil level is better. I did some brush hogging in tough brush and had no problems with brush poking the engine or moving the throttle.

Today (while moving the ignition switch) I discovered that I can remove the battery now without undoing anything other than the two terminal bolts and the hold down clamp. That was a pleasant surprise.

Phil

 

[MossRoad]

Sounds like a good deal all the way around. :thumbsup:

 

[woodlandfarms]

Given that I run in trees the engine cover feels pretty neccessary, and I am not as sold as you are that it causes heat retention. But that is for science to figure out, you feel it is lower so it is... I wonder, in terms of giving the engine a little protection, if you could run a few bars along the cover, like a brush guard.

This is a way cool swap BTW, Those little predators have got a huge following as an inexpensive yet reliable engine. If you blow it, you still have two more to go buy before you equal one robin.

 

[Phils]

Given that I run in trees the engine cover feels pretty neccessary, and I am not as sold as you are that it causes heat retention. But that is for science to figure out, you feel it is lower so it is... I wonder, in terms of giving the engine a little protection, if you could run a few bars along the cover, like a brush guard.

This is a way cool swap BTW, Those little predators have got a huge following as an inexpensive yet reliable engine. If you blow it, you still have two more to go buy before you equal one robin.

I don't believe those screens "make the difference" in heat retention, just that they have to restrict airflow somewhat and removing them HAS to help.

The BIG deal is the exhaust. Only the people with the Robin and that hacked together exhaust "system" can really appreciate the difference. Most of my planning for the conversion was figuring out a way to make a decent exhaust. I was still planning on porting it out the side like stock, but a trusted friend made such a good case for keeping the stock exhaust, I found it simpler to move the gas tank. Then I was gonna cut a hole in the screen for the exhaust. Then removing the whole side seemed better, also solving the "how/where to mount the choke" problem. It was, as usual, something that evolved.

I sure agree on the price for these motors. If there were a big number of bad reviews, the choice might be harder.

I didn't have an engine hoist, so I used my HF hydraulic press.

Phil

 

[cqaigy2]

Another good idea to remember, i have one of those HF presses.

 

[Frank Sorbello]

Did you use the same engine stand?

 

[QRTRHRS]

I am debating replacing the 23hp Vanguard on my zero turn with that 22hp HF engine. Is there a spec sheet for the HF engine that shows the dimensions? On my application, the rear of the shaft drives the magnetic clutch and the front drives the hydraulic pumps.

I was hoping to get the season out of it before it died but when I started it yesterday, it sounded like had a valve issue. I pulled a cover and found both valve pushrods bent. I straighted them out the best I could, adjusted them and adjusted the other bank for good measure. It started but the other bank was not firing. The coil for that side went bad. Along with that, it uses and blows oil so if I can do a quick and reasonably priced swap to get though the season then that sounds like a plan.