PT422 Engine shaking / sputtering

[Gravy]

Update:

I received my EH72FI in three business days, and it even included lift gate service which surprised me. I'm trying to take pictures to document the swap and I have the old motor pulled. It turns out the EH65 had a 1 1/8" shaft (and not the 1 7/16" I was led to believe). So I need to order a new coupling. I wish I figured that out earlier since I could have ordered the new engine with a 1" shaft and saved $100. Oh well...

I'm hoping someone here might know more about these couplings than I do... I need a coupling with 1 7/16" bore and 3/8" keyway. The current coupling is 2.5" in diameter and and about 2" long. I think the Lovejoy "L" series would work but I'm having trouble tracking down the complete specification and dimensions for the various models. Here's a link to the pdf file I've been looking at (page JW11). There appears to be 5 models with 1 7/16" bore shown about 3/4 of the way down the page.

Redirect Notice

L110 11746
L150 12114
L190 12295
L225 12431
L276 12591

What do you guys think? Does anyone know of a better resource? Thanks again for everyone's help so far.

grainger.com catalog page 169.

Grainger Industrial Supply

Looks like 2.5" od is an L100 size. The smallest coupling in the Grainger catalog with a 1.75" bore is a L150, which has an od of 3.75".

Are there any numbers stamped on your coupling? The Lovejoys that I have seen all have the model number stamped on the body. If there are no numbers, it may be that PT used some other brand.

 

[KMA]

Thanks Gravy. No numbers on the coupling, but the spider does have "L099 L100" on it which fits what you found. That's all the markings I could find. This is unfortunate because I could have gotten the 1" shaft motor, saved $100 bucks and easily found a new coupling in the L100 series to fit. I'll probably call PT tomorrow and see if they've used this size coupler before and have something to sell me. Thing is, Terry told me to get a EH72 P/N EH720-DS0032 to replace my EH65. That part number shows a 1 7/16" shaft which is why I ordered that size. Maybe PT has something that will work. A larger coupling may fit in the housing, but the pump side uses a spline setup vs a keyed shaft, so I'd have to sort that out too. Nothings ever easy...

If it comes down to it, I might be able to get the current coupling machined to fit the new shaft. It appears there is just enough space between the "jaws" that mate with the spider. I don't think it would weaken it too much, but adding a cutout for the keyed portion maybe remove too much metal. I'm thinking I could add a 3/8" set screw that with go all the way down into the shaft's cutout and avoid the key as a last resort.

 

[KMA]

Quick update with some good news...

I spoke with Terry and they machine their own couplers that should work with the existing ones and the larger shaft. He said they use motors with that size shaft on their tractors and it is not an issue. The part was $40 and should ship tomorrow.

 

[Gravy]

Glad to hear it. I don't think the cast iron L100 would hold up well bored out to that size. PT might be making them out of a higher strength steel.

 

[3238dpw]

So how is this going KMA?

And how about your new engine Vacuous one? How is your new engine in your machine?
Any updates?

 

[KMA]

Scott,

The new engine seems to be working fine. I bought a Ferris ZTR for the lawn, so my "PT428FI" hasn't seen as much seat time this summer. I did notice a slight increase in power, e.g. it goes up hills with the mower/PTO engaged a little bit easier. Starting (sans choke) is easier too, although I'm not yet convinced it will completely address the cold weather starting issues I've had (I think it has as much to do with trying to turn the pumps filled with cold oil than anything). I had some vapor lock issues, which I think I've addressed. The fuel line elbow coming out of the tank has some plastic debris. I also rearranged the fuel line and return, and played around with the radiator fan I have attached to the engine bay cover. It was only an issue when mowing the lawn in warm weather, and occurred after 45 min or so. Since I have a new mower I'm not 100% sure it is completely resolved.