Frequently Asked Questions

Why does the engine shutoff when I let go of the Murphy (shutoff) switch?

Most of ODB’s leaf collector engines are equipped with a Murphy (shutdown) switch that shuts the engine off when an event happens. On typical units there are 3 events that shut the engine off. 1- low oil pressure, 2- high engine temperature, 3- limit switch on the blower housing inspection door is tripped. When the engine first starts, the engine has little or no oil pressure, so the shut off button needs to be depressed to bypass the shut off mechanisms. Then after 5 seconds, the shut off button can be released and the engine should continue to run. If the engine does not continue to run, then a technician should investigate one of the three events above to determine which one is shutting the engine down.

When installing a new impeller how far away should the impeller back be from the rear of the blower housing?

As long as the impeller back clears the bolt heads of the blower housing then it is okay. Make sure the impeller and the impeller bushing meet. The bushing should be flush with the impeller shaft.

I can’t get my old impeller off. I used the bolts that came with the bushing to drive the bushing out but it didn’t work. Is there a trick to getting the bushing off of the shaft?

See your service manual for complete details but here it is in a nutshell. Spray the bushing with a lubricant, then drill and tap 2 more holes in the lip of the bushing. Use 2” long grade 8 bolts in all four holes and it should drive right out.

One of the blades of my impeller has broken, can I weld it back and re-use the impeller?

No! Let me say it another way. NO! Never try to fix or modify the impeller. If the impeller becomes damaged, vibrates or is worn replace it immediately. 

The unit is vibrating like crazy, but only when I put the PTO in gear, what’s the problem?

Most likely the impeller is out of balance and this can cause tremendous damage to the entire unit. The impeller needs to be replaced. Even if the impeller looks like it is worn evenly it can still be out of balance a little bit, and when the impeller is turning at 2,200 rpm a little out of balance can cause major problems.