Oil & Fuel Gas Tank

[ldabe]

By the way, if
Jack Robin
sees this, I would appreciate his input ;~)
(Just thought of something, if the Robin is really a Subaru, why don't they even come close to operating like a Honda, including the quietness?)

Since Jack Robin has not answered about the difference in Subaru and Honda, I was wondering if anyone else had any input?

I know the Subaru (Robin eng.) company started a few years after Honda, but since they both are Japanese engines, why does the Honda seem to be such a better quality made, and always quieter than the Subaru's (Robin)?

I have never owned a Honda engine, but I have used many at my work place, and have rented a couple (ie. generator, post hole digger, etc.) and they just seem to out perform other engines.

Is this just my perception, or does anyone else see it this way also?

 

[J_J]

Since Jack Robin has not answered about the difference in Subaru and Honda, I was wondering if anyone else had any input?

I know the Subaru (Robin eng.) company started a few years after Honda, but since they both are Japanese engines, why does the Honda seem to be such a better quality made, and always quieter than the Subaru's (Robin)?

I have never owned a Honda engine, but I have used many at my work place, and have rented a couple (ie. generator, post hole digger, etc.) and they just seem to out perform other engines.

Is this just my perception, or does anyone else see it this way also?

I think the difference is the tolerances on the engine parts that make the difference, but you have to pay 1/2 to 2/3 more for a good reliable engine. I use both Honda, and Kohler, and they seem about equal in operation, and longevity. I think PT is using the Robin, because they got a good deal on the engines, and they can still get the same price for a Robin powered PT. I like my Ford industrial 4 cylinder that is in my PT. It was probably a test bed for the earlier PT's. It is quite, and has never bogged down. The hydraulics start to groan if I over work it. I don't think Jack is allowed to compare the quality of the two engines, although he probably knows the truth.

Honda is probably the only manufacture that puts a fuel shut off on all there engines, and a carb bowl bleed screw , both are a good thing.

 

[Gravy]

My internet research before I bought my PT actually indicated that Robin engines are overall even MORE reliable than Hondas. Rental companies in particular loved the Robin engines. HOWEVER: I suspect that data applies mostly to the single cylinder models. My personal experience with a Robin 25hp engine leads me to believe that it is basically a good engine, but that it isn't as well developed as the singles. It doesn't like to start when it's cold, it has fuel delivery problems, I had an oil cooler hose blow off, and I've had several air filter failures (filters leaking dust into the engine instead of plugging). It still works, but it could be better.

Given that Robin is a division of Subaru and evidently WANTS to be a quality leader, I'm confident that the bugs will get worked out and the v-twins will eventually be great engines. However, with the convoluted legal system in this country, I doubt that Robin/Subaru will be officially admitting to any flaws in the existing engines in our PT's. If they did, some attorney would be demanding that they recall every engine they've sold in the last 50 years...

I'm pretty sure that PT uses the Robin engine because it costs significantly less and the quality is acceptable. PT seems to be a "bang-for-the-buck" kind of company. The difference in refinement and noise probably doesn't offset the cost difference. The PT-built "muffler" is evidence that noise level isn't a concern at PT. It would be hard to hear the difference between a Honda and a Robin with that abomination installed on both.

IIRC, the published power/torque curves indicate that the Robin 25hp really does produce a bit more power than the Honda 24hp. Kohler has some engines that do better, but they are a lot more expensive than either the Robin or Honda. The idea of a hotrod 4xx machine is cool, but I doubt that PT would sell enough of them to justify the expense.

Gravy

 

[Phils]

Since this thread has wandered off topic already, I'm curious if anybody knows whether Suburu changed anything when they bought Robin from Wisconsin? When I worked at an auto parts store years ago, we were one of the only parts suppliers in town for the Wisconsin Robin engines and although I looked at many Robin parts books, I didn't have much to do with the actual motors and don't know if they are the same or different now with "new" ownership.

Phil

 

[ldabe]

Since this thread has wandered off topic already, I'm curious if anybody knows whether Suburu changed anything when they bought Robin from Wisconsin? When I worked at an auto parts store years ago, we were one of the only parts suppliers in town for the Wisconsin Robin engines and although I looked at many Robin parts books, I didn't have much to do with the actual motors and don't know if they are the same or different now with "new" ownership.

Phil

Phil, I hope Jack sees this thread and chimes in.
I believe he would be the best one to answer your question and mine.

To get back on the topic of the "gas tank", the odor of gas has went down considerably since I turned off the gas cock I had installed, and a couple days went by.

So, I am assuming that the strong odor was from what was left in the carb after shut down.

 

[ponytug]

I'm glad you found a way to cut the gas leak down! Plus it is a great safety feature to have.

If shutting the fuel line helps, I would suspect that all is not totally well with your carburetor. Either gasoline is leaking out of the bowl due to a bad seal somewhere, or the float valve is leaking, or at least leaking when there is no air running through it. The former is a fire hazard, the latter, poor fuel economy, gasoline in your oil, and perhaps some carbonizing of your engine.

All the best,

Peter

Phil, I hope Jack sees this thread and chimes in.
I believe he would be the best one to answer your question and mine.

To get back on the topic of the "gas tank", the odor of gas has went down considerably since I turned off the gas cock I had installed, and a couple days went by.

So, I am assuming that the strong odor was from what was left in the carb after shut down.

 

[ca956]

Ldabe,

I feel your pain !!! I have a PT-425 with Robin engine (350 hrs). It will not start below 50 degrees. I have voiced this concern once before, see thread "happy or unhappy" . I found it manditory to have one of my workers "babysit" the PT with a torpedo heater blowing on it every morning to make sure it would start. I have the same gas smell as you described. With mine it is not a leak, it is a flooding condition cause by the engine not starting. I have tried new plugs, hi-octane fuel and adjusting the rocker arm clearence. None of this has made a difference. My beleif is that the problem lay in the timing conditions of the engine. Either cam timing and/or ignition timing. However I have not yet found a way to adjust either. Between my father and myself we have at least a dozen pieces of equipment ranging from 60+ horspower tractors to 3 horse power pushmower. Out of all these machines the PT is the one that will never start. I own a 5.5 (HONDA) horse power "Little Beaver" posthole digger, that is aleast 10 years old. This machine rides in the back of the truck and is left at the job site with a wheelbarrel over it to protect from the elements. It can sit for days, weeks or months and with 1 or 2 pulls IT WILL START !!! It always starts.
The PT was purchased to replace the "Little Beaver". On more than one occasion the "Little Beaver" has been pulled back into service because the PT
would not start.

 

[ponytug]

I won't mention taking it to a Kohler dealer, because if it were an option, I assume you would have tried it. These engines should start just fine to 0F. Once it is running does it run OK?

Get the service manual. You probably want to check the air filter, but I am sure you have checked/cleaned it. With it off, you probably want to check the choke operation. If you don't have a bad float, this is probably your problem. Then check the adjustment of the gas jets. If you smell gas, you know you have too much fuel going in, so you can start by shutting the main jet down, if the choke checked out OK.

You mention checking the timing- did you actually strobe it to check TDC, or just the adjustment? If you are getting a reasonable spark when you crank it, it would be a rare failure.

I am somewhat concerned that there is some systematic problem, like a leaking float in a production run of these engines.

Keep us posted.

All the best,

Peter

Idabe,

I feel your pain !!! I have a PT-425 with Robin engine (350 hrs). It will not start below 50 degrees. I have voiced this concern once before, see thread "happy or unhappy" . I found it manditory to have one of my workers "babysit" the PT with a torpedo heater blowing on it every morning to make sure it would start. I have the same gas smell as you described. With mine it is not a leak, it is a flooding condition cause by the engine not starting. I have tried new plugs, hi-octane fuel and adjusting the rocker arm clearence. None of this has made a difference. My beleif is that the problem lay in the timing conditions of the engine. Either cam timing and/or ignition timing. However I have not yet found a way to adjust either. Between my father and myself we have at least a dozen pieces of equipment ranging from 60+ horspower tractors to 3 horse power pushmower. Out of all these machines the PT is the one that will never start. I own a 5.5 (HONDA) horse power "Little Beaver" posthole digger, that is aleast 10 years old. This machine rides in the back of the truck and is left at the job site with a wheelbarrel over it to protect from the elements. It can sit for days, weeks or months and with 1 or 2 pulls IT WILL START !!! It always starts.
The PT was purchased to replace the "Little Beaver". On more than one occasion the "Little Beaver" has been pulled back into service because the PT
would not start.

 

[J_J]

I believe that Idabe has a Robin engine, and there is no way to adjust the timing, because timing is set or increased electronically as the rpm increases.

On the fuel thing, If your tank is above your engine, it is a must that you have a fuel shutoff valve installed. When you remove your gas cap, do you get expelled air, or do you hear a vacuum hiss? If you are getting expelled air, the pressure might be over riding the needle valve in the crab bowl, and forcing fuel into the engine, and therefore fumes, and thinning out the oil.
The manual also mentions something about a cold start enrichment system. You would have to ask your dealer/mechanic about that.

 

[cqaigy2]

I've got a 422 with the robins engine in it. It doesn't get very cold so i think it was about 25 degrees is the coldest its been when ive started it up. That's with a full charge on the battery cause the battery is kinda weak.