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hancox

518-H hunting throttle - pulling hair out

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hancox

So, I was the lucky recipient of a '89 518H - a shade under 500 hours on it.

Late last season, the throttle started bouncing uncontrollably. I had the carb professionally serviced, and it ran fine for about 3 hours (which unfortunately spanned the winter, so going back to same service place is probably not going to work)

Symptoms:

- Bouncing throttle (usually starts after about 10-20 min runtime)

- Will stall when I engage pully quickly, usually need to gingerly engage it

- Can *occasionally* get it to run somewhat normally with a quick choke hit, although not always, and never for long.

I'm giving it a good 30ish min soak with MMO straight down the carb for now - maybe even longer

Otherwise - the tractor is in fabulous shape - it's been garage-kept most of its life, and has never left my family.

Please help me from donating it to some lucky person who is better with engines! :whistle:

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rocking 416

i look at the govener spring tenstion . you can look up the procedure on how to adjust it properly on toro.com u need ur tractor model an u can d/l the manuel an print it out but loook under carb an linkage adjusments cuz it could also be the rod that goes grom the govener to the carb that could be bent, out of adjustment,ect hope this helps an sorry i can not link you to toro.com

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Jim_M

I'm guessing you have some dirt in the fuel system. If you don't already have one install an inline fuel filter in the fuel line between the tank and fuel pump.

It would be best to pull the carb and clean it, but you may get lucky and be able to disolve the dirt with some good cleaner. I like seafoam carb cleaner, it's good stuff. I buy it at my local napa. TSC also sells some good stuff, it's called Chem-Tool, it works almost as well as Seafoam.

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hancox

Couple of notes:

1) inline fuel filter was present before/after service - was replaced as part of carb repair.

2) Looking at page 7-6 in the onan manual - going to look at the governor spring.

Wish me luck! :whistle:

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nylyon

When you winterized it did you run it out of gas? You can try to clean the carb a little without taking it apart. Close the gas petcock, and run it completely out of gas. On the bottom front of the cab there is a plug. Remove that plug (a little gas may come out) spray inside with gumout especially where the jet is. You will be able to see the jet through the hole.

If you do donate it, I sure hope you're near me :whistle:

Welcome to RedSquare

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hancox

When you winterized it did you run it out of gas? You can try to clean the carb a little without taking it apart. Close the gas petcock, and run it completely out of gas. On the bottom front of the cab there is a plug. Remove that plug (a little gas may come out) spray inside with gumout especially where the jet is. You will be able to see the jet through the hole.

If you do donate it, I sure hope you're near me :whistle:

Welcome to RedSquare

I'm about 30 min from you in Monroe, CT :D (uh oh - I'd better fix this! :WRS: )

Going to let the engine cool down a bit, and try this, too. Thanks all!

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Rollerman

Another thought....whats the inside of your fuel tank look like?

If there is any crud/sediment in it it could be causeing a clog at the inlet screen?

There's a small screen in the tank just inside above the fuel shutoff petcock.

Hope you get it figured out, but does sound like a fuel delivery problem.

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Dual Wheels

I had the same problem with a 520H...turns out the idle jet was pluged up and it was running on the main jet. All it took was removing the idle mixture screw...spraying carb cleaner in the hole and the air passage port in the throat of the carb ..runs fine now. One more thought is the fuel line...if it's the origanal line ,it could be rotten on the inside hece the gas is picking up tinny pieces of fuel line which replugs anything you clean. the first thing that I replace on a tractor I buy to get running is the fuel line...has saved me alot of problems.... :whistle:

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hancox

Hmmm - did notice something wheick I find odd. Where is the line that ends in the airbox with the octagonal nut supposed to be hooked up to? Mine is open, with clamp on end and a VERY small hole at the end.

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hancox

Another thought....whats the inside of your fuel tank look like?

If there is any crud/sediment in it it could be causeing a clog at the inlet screen?

There's a small screen in the tank just inside above the fuel shutoff petcock.

Hope you get it figured out, but does sound like a fuel delivery problem.

Can see clear to bottom of tank with flashlight - totally clean.

Also released the petcock (was sealed for nylyon), and flow could be clearly heard bubbling through.

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nylyon

Can you take a picture of that line? Let me know when you give up, trailer ready! :whistle:

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Dual Wheels

I wondered about that hose allso until I looked and all four were the same...two 416's and two 520's....soooo I guessed thats the way they are suposed to be. :whistle:

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nylyon

Still at a loss on which hose you are talking about. There is one which is large and that is the air intake from the blower housing. The second is smaller and that is for the breather. It shouldn't be restricted at all, so if you have a picture that would be helpful.

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Dual Wheels

The hose is conected to a brass fitting on the underside of the bottom half of the air cleaner housing it's only about 1/8 th id. It lays across the top of the motor towards the battery. It's hard to see, unless you remove the air cleaner bottom . The end hangs loose and looks like it was connected somewhere and broke off, at least that's what I thought when I firt saw it. Still don't know what it is for but all mine are th same :whistle: I'm at work so I can't send a picture ..but I don't see it haveing anything too do with the fuel flow

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hancox

Karl - guess I should qualify the word "donate" :whistle:

Dual Wheels - amazing thanks for saving a possible hair-raiser in thinking I pulled something out. :WRS:

Is totally removing / replacing that screw safe for a noob like me? Worried about:

1) Anything falling out

2) Setting it back once done

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hancox

Oh, and to add insult to injury, of course it ran smooth as glass when emptying out the fuel line again this AM

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hancox

So, I got it to run just great....for about 15 or 20 minutes. I hit a bump, and it went back to $%^#$^@#$%@#%!@#$% It was running better than ever for those 15 mins (ARGH)

Dual Wheels - I'm thinking you may be right on the fuel lines. I'm just hoping I can manage to replace them.

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hancox

Any ideas on where to pick up parts like the fuel lines? May have time this weekend to try it

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MaineDad

Any auto parts store will sell fuel lines. Bring in a piece of your old line to make sure they match. I'm guessing 1/4" hose - maybe bigger.

He's in CT - I'm not far for a donation :whistle:

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hancox

...should have known better then to say "donate" on a board like this - you guys are like hamsters :whistle:

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wse100

If I give some advice does that put my name in the hat for a possible donation recipient? This could be my second horse :whistle:

Here is my advice: PM TT and ask him what he thinks, of course doing this will most certainly mean getting your Tractor fixed...Thus making the whole donation thing obsolete, but at least I could help :WRS: :D

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Teddy da Bear

It sounds similar to the problem I had with my C-100.

I finally figured out what was going on. The choke handle position and butterfly in the throttle body did not correspond. (read 7th horse came home).

I think my choke has some "slop" in it and moves from partial choke to no choke periodically. I could be missing a return spring somewhere.

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hancox

So - replaced all fuel lines, and now I'm getting no gas visible in the fuel filter :whistle:

Do I need to "re-pressureize" the lines somehow? Apols for what is probably a very noob-ish question...

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nylyon

Some silly questions. Did you turn the gas back on by the petcock? If it is on, disconnect the line before the fuel pump and blow some air through it, it should bubble in the tank. If that is good, hook it back up again and check on the other side of the fuel pump.

Is the fuel filter on the correct way? Some have a check valve in them which, if installed improperly would prevent the flow of fuel.

Other than that, perhaps the fuel pump isn't pumping?

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hancox

Hoping it's not # 3 :whistle:

Petcock def. unscrewed. Fuel filter has an arrow for direction of fuel, so that one's hard to screw up :WRS: (even for me)

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