Onan 520-8

[Tankman 3,523]

Just started to renovate a '90 520-8 Stallion. Lucky to find one!

Two questions 'bout the Onan. 1st is simple.

1) The grommet around the oil filter is kaput. Is this a necessity (to have)?

2) Was told the engine runs. I did crank the engine manually using the flywheel bolt just to lubricate the engine. Oil level is fine. Is there a way to bypass the electrical system, start and run without using the key or the WH 'lectric system?

[varosd 1,185]

My 520 doesnt have the oil filter grommet. EricJ pointed this out to me. He thinks it might limit the loss of cooling air through the hole and make it cool the back cylinder better. I can't find a part number on Partstree. does anyone have a part number or picture?

[buckrancher 2,694]

Duke (Horsefixer) should beable to give you that part number

[Kelly 1,033]

Most of my Onan are missing the rubber around the filter, or were, I bought a pile of them off ebay a year or so ago, I'll see if I have the part no. and yes it should be replaced, it helps on cooling. you can start the onan with out the tractor that is easy run a wire from the pos post on the batt. to the + side of the coil, (you will have to unhook this to shut it off) have a good ground to the block, hook the pos side of the batt to the starter, run a wire from the pos. side of the batt. to use to engage the starter, you can touch it to the small tab on the soliniod to make the starter turn, remove when started, or put a push button in line to crank engine, BUT onan charging systems can be damaged by not having a batt. in line, not sure how you will want to go about that.

[sorekiwi 761]

I bought the grommet from my Toro dealer a couple of years ago. It was cheap.

Toro also lists most of the engine parts (with Toro numbers as opposed to Onan/Cummings numbers). I've bought a few engine parts through my local Toro dealer rather than having to get stuff shipped to me. The tractor parts manual has quite a few pages of engine stuff.

If you run the engine without the grommet in place, you can feel how much air rushes out around the filter. That air would be better used to blow over the cooling fins of the cylinder head.

[Tankman 3,523]

My 520 doesnt have the oil filter grommet. EricJ pointed this out to me. He thinks it might limit the loss of cooling air through the hole and make it cool the back cylinder better. I can't find a part number on Partstree. does anyone have a part number or picture?

Here's a link to the listing on Parts Tree: http://www.partstree.com/parts/?lc=toro_consumer&mn=41-20O801%2C+520-8+Garden+Tractor%2C+1990&dn=810689R1-89R10042-00020

Item #9, inexpensive, odering one myself.

[ericj 1,579]

hey Don sorry about not getting back to you with that part # but here it is 0122-0502 that's the onan part #.

tankman, you could bypass the electrical system but,,,,, you have to be real careful not to damage your voltage regulator. if the motor is still on the tractor you can run a jumper from the battery to the coil to power it and pull the i believe it is a blue wire off the starter ( the one that just slides in with a stay-con style connector ) than jump a wire from the battery wire on starter to that terminal and it should crank over and fire with the jumper on the coil. if the motor is off the tractor i would think you should be able to put a jumper on the center off the voltage reg. and the battery to avoid destroying your reg. the voltage reg must see 12 volts to avoid damage. you will already have the battery hooked up to the starter and just mount a ground wire. ? just ask i i will help the best i can or maybe soi can help

eric j

looks like other people beat me to the punch

[varosd 1,185]

Dang I must have looked at partstree and my paper copy of the 520 parts for a year and never saw it!!! will get one!