520h Throttle Malfunction

[mattd860 162]

The throttle lever on my 520H will not stay up! When snow blowing this weekend, the throttle lever will slowly drop from max down to 3/4. Is that indicative of an incorrect spring or worn throttle cable/lever?

It's really annoying having to hold the lever up to max rpm while trying to maneuver the tractor. Thank goodness for the custom foot pedal though!!!

[Rollerman 290]

Matt the throttle pivot has an amount of friction built into it that after years of use will go away.

You can try to remove the throttle assembley & peen the pivot point on it.

This will tighten the lever back up so you throttle won't back off.

It's more of a temp fix till you can get a new replacement.

[tunahead72 2,347]

Matt,

You don't necessarily need to remove the throttle assembly, you might be able to tighten that pivot point with a pair of vise grips. I've had good luck with that method, check here for more information:

http://www.wheelhors...lips-back-down/

[stevebo-(Moderator) 8,059]

Matt,

I have done what rollerman has suggested however I have found the best fix is to drill out the pivot point then through bolt using 1/4 bolt with washers and a nylon locking nut. Works great for me..

[mattd860 162]

Thanks everyone - I will take a look today and see what solution I'll go with.

[P3x 55]

The throttle on my 520 creeped down to about 60% power and continued to get worse. I tried the vice grip squeeze fix and only got worse so I removed the throttle lever assy planning to drill out the rivet and install a screw as mentioned in the posts. After seeing its installation it lookks an easy enough fix to redrive the rivet to tighten it up. I'm fortunate to have retained a lot of tools from my aircraft wrenching days and repaired it by taking a rivet gun - actually used a low pressure hit husky muffler tool to be safe with a flush set mounted backing up the shop end with a bucking bar and redrove the rivet. Nice and tight now and smooth through out its travel range with no creep.

I believe it will be a permenant fix, but time will tell.

P3x MA

[can whlvr 991]

let us know how it works

[P3x 55]

Finally had snow (slush) and a chance to check the throttle fix. Works as it suppose to in any setting with no more creeping to lwr RPMs. But broke the nipple off the Air Filter Diff. Press. Switch some where along the line - cannot believe the prices they get for a new Sw - $70-85.00! Got out the JB Weld and good 2 go.

[chipster2005 7]

Nice job guys working it out together! P3, awesome inovation! I have the same problem on my inherited 416-8...gonna rivet it today...Im a copper/sheet metal craftman and have the tools too. Im sure it'll do well and I'll be cautous not to damage anything else in the process . Btw Im planning a valve job on my Onan in a few days or so.. Anyone got some tips? Thanks WH fans!

chip

[kpinnc 10,981]

Btw Im planning a valve job on my Onan in a few days or so..

Take plenty of money, and get the parts total while you are in a seated position. Onan parts are stupid expensive, even the gaskets.

Worth it if the engine runs great afterward, especially in your tractor's case, but prepare yourself for sticker shock.

[P3x 55]

If you need the gaskets/parts to do the valve job, Onanparts.com has fairly good prices. They have a Valve Grind Gasket Kit for $42.50 (http://onanparts.com/index.php?main_page=product_info&cPath=1_7_19&products_id=18). Not sure if this kit is applicable to your Onan.

Let me know how it goes as I've been planning to decarbon my 520.

Good luck!

[chipster2005 7]

P3x,

Thanks for the link..Ill be ordering that soon...ordered the tune up kit from a local Toro dealer Monday...waiting on that then gonna clean carb. When the valve kit comes Ill let ya know. Thanks again

chip