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Re: 644 & 646 disapointing results
Posted: Thu Jun 23, 2022 11:17 am
by Eugen
Harry wrote: ↑Thu Jun 23, 2022 10:27 am
I eliminated the electric fuel pump then checked it again wiring it directly to battery. No pumping and was going to put on a mechaical Onan pump which is powered by the cam from a donor engine. I replace the diaphram on it mounted it on the engine and could not get a drop out of the pump, even after priming it. So now it's unto plan C which is what Boomer mentioned last week during a phone conversation. Pulse pump which many small engines have today. He mentioned I could connected the vaccum side of the pulse pump up to the dipstick tube. I was thinking maybe I could attach it to the breather which is in close proximity to the carb. Anyone have any other ideas out there?
Keep the Peace
Harry
@Harry why not get the proper mechanical pump for the Kohler K321? That worked on the original engine for many years, and with a new one it should work for many more years. Or you are talking about the 646 here? I might have gotten confused.
Edit: never mind, I went back and read the thread, you were talking about the 646. I do not have any ideas about that, sorry.
Re: 644 & 646 disapointing results
Posted: Thu Jun 23, 2022 11:46 am
by Harry
Yes Eugen, this is an Onan CCK engine. The mechanical fuel pump is similiar but slightly different than the Kohler 321 pump. I was thining of rebuilding the Onan mechaical and try to get a kit from Boomer, but he said try a pulse pump instead. I'll have in tomorrow and was just reaching out for ideas where to plumb it to.
Keep the Peace
Harry
Re: 644 & 646 disapointing results
Posted: Thu Jun 23, 2022 12:02 pm
by DavidBarkey
Harry wrote: ↑Thu Jun 23, 2022 10:27 am
I eliminated the electric fuel pump then checked it again wiring it directly to battery. No pumping and was going to put on a mechaical Onan pump which is powered by the cam from a donor engine. I replace the diaphram on it mounted it on the engine and could not get a drop out of the pump, even after priming it. So now it's unto plan C which is what Boomer mentioned last week during a phone conversation. Pulse pump which many small engines have today. He mentioned I could connected the vaccum side of the pulse pump up to the dipstick tube. I was thinking maybe I could attach it to the breather which is in close proximity to the carb. Anyone have any other ideas out there?
Keep the Peace
Harry
Those pulse pumps are the best way to go . The easiest is the dip stick tube as it can easily be removed to install a vac. fitting . Make sure you have a good seal at the dip stick it's self and put the fitting about 3/4 sway up the tube . Mount your pump higher that the fitting so any oil build up will drain back to the tube .