Kohler offers a competing standby generator to my Generac, which I will assume uses some variant of that 15 HP engine. The Generac I have here uses a Generac-built engine.
I am linking to an exploded parts drawing from the Generac service manual for the area I am discussing / working in. Not sure it adds anything useful, but it illustrates how the bellows attaches to the air filter base on one side and the engine on the other:
Smarty wrote: ...
That ain't no clamp problem; the carb intake centerline is well below that of the air filter. You need to do whatever it takes to line them up -- ideal would be if there's play in the mounting holes for the filter base that would let it be moved down sufficiently. Otherwise either shim under the engine to raise it, elongate mounting holes for the filter or combinations of both or whatever it takes.
It's clear that kind of stress on a light rubber piece will shorten life significantly.
Since the weather was permitting today, I disassembled all of the related parts and confirmed that there is a misalignment of the type you described, maybe a total of 2 to 3 mm of vertical offset and another mm or 2 of lateral offset. This definitely puts a pre-load on the bellows, and I will have to concur that the stresses must be the root cause of the weakening / wearing of the bellows prematurely.
I intend to correct the vertical offset by elongating the mounting holes into vertical slots. I will probably get a little more wiggle room horizontally as well, probably enough to gain a mm or so laterally.
I will report back on my progress.
Many thanks once again, and I have recognized the value of photography to solve these types of problems.
Duct tape?
Now I see it, I didn't keep up with what Generac was doing with their own engines. The problem I've been having with the old Vanguard engined
8kw units is the oil pressure switch, I've had to replace dozens of the darn things.TDD
1) Frankly, at $5 per it's no exactly a bank breaking repair.
2) That said, from the picture is looks like it could handle a LOT of vibration and relative motion between the carb and the air filter. I don't think a simple hose would work or, worse, it would transfer too much force between the two parts and damage one or the other.
3) and THAT said, since it connects the carb with the air filter, it would operate with a slight negative pressure. You might try "repairing" an old bellows or rein-forcing a new bellows with "liquid latex on the OUTSIDE.You also might want to see whether the engine mounts are all sound. But it looks like the vibration is sort of built into the design.
Have you observed this with the engine running. Perhaps the intake pulses induce an oscillation in the bellows causing a fatigue crack.
Thanks for your comments John. The $5 cost for the part is really irrelevant. The frequent failures and the resulting loss of confidence that this standby generator will truly work in the rare occasion when I really need it are the big issue. And finding a way to avoid having to replace this part every nine or ten months is the mission I have been on here.
What I have (finally) learned is that the Generac "Master" technician, sent out during the warranty period from a very old and established Generac dealer in this area, made 2 huge mistakes.
The first mistake was to assume that the $5 rubber bellows was at fault due to a defect in manufacture, telling me that a newer, improved part was being installed. The folks at Generac tell me this was not true whatsoever.
The second mistake, and the crucial one, was that this same technician made no effort whatsoever to see *****WHY**** it failed. I now see, having taken apart and photographed the parts, and getting excellent help here on this newsgroup, that the rubber bellows was being distorted quite severely at rest, making it pre-loaded and distorted.
It turns out that there are some slotted adjustments to move one end of the assembly around, thus allowing for correction of the misalignment.
This slotted alignment set-up is NOT mentioned in the owners manual or the service manual. The technician apparently did not know that there was an adjustment, and replaced the broken bellows with another one, which then failed once again in less than a year. Had the root cause been identified, I would have been spared all of the subsequent replacements, all of which I have performed, assuming that the rubber bellows was somehow weak or defective.
I briefly did install a "hump hose" made of silicone, before the misalignment and adjustment option was discovered, and it appears that this may have also "solved" the problem by providing a stronger connection. But as others have pointed out here, and I observed, the use of a hose, especially a stiffer and less compliant hose, transmits a lot more vibration into the remaining parts, and is not an optimal solution.
I think I have this problem solved, but the real test will be if I have no further issues for the next several years. Other owners seem to be getting very good reliability, and I hope to join the happy users now that this is resolved.
This newsgroup has been an invaluable resource to me, and I am sincerely very grateful for the really outstanding suggestions and guidance. Thank you !!!
Lost meat from freezer: $475 Grandpa stroke, cost of ambulance ride $600 Grandpa's night in hospital $7542.36 Lost work at home office for two days $364.24 Motel room till Generac part comes $175
Yeah, it's only five bucks.
I guess with all that on the line you should have paid for a more reliable unit, had it serviced more frequently, or had another spare.
If winter, bury the meat in the snow.
Largely covered by insurance.
Go ice fishing.
Fish all night!
Glad the OP might have a fix with his experience and adjustments.
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