# Recoil Starter yanks back



## EdwardC (Sep 26, 2016)

I have a 1990 Toro 521 with the original Tecumseh HS50 (I think that's the number). 

I only purchased the blower last year and it was used maybe twice. I drained the tank and ran it out of fuel earlier this year. I refilled it a week ago, hit the primer bulb a couple times and tried start it. I noticed that the motor would violently yank back as I pulled. It took quite a few pulls, but I eventually got it running and it sounded like it ran well. I can't say for sure if it's combusting at the wrong time, or if possibly the compression release is broke, or something else.

I've seen in mowers where a sheared flywheel key can cause the same symptoms. I understand that a sheared flywheel key isn't as common on a snowblower, and if I understand right, it won't run well (or at all) if it was sheared. My next guess is to check the valve clearance. Any other suggestions?

btw, my Honda HS621 started up easily on the 2nd pull! Makes me want to find a used GX160 or GX200 to repower with...

Thanks,
Ed


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## leonz (Dec 12, 2014)

I would gap the plug to 25 thousandths of and inch and always be sure to have the piston at the top of its stroke when you try to start it so the compression is being exhausted.

In saying that if you have a salamander/torpedo heater using that for ten minutes will eliminate the hard starting issues every time. it saves wear and tear on the engine and the need to fill it with ten weight oil to let it run well in winter.


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## EdwardC (Sep 26, 2016)

Thanks leonz! I'll take a look at the plug which I think I put in new when I bought it (or I bought a new plug but haven't put it in yet). It was actually fairly warm when I was trying it (I'd guess in the 40s or 50s), but I have a heat gun near by just in case I need to warm it up a little. I think I put either 0W30 or 5W40 when I got it to help with the cold starts too.


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## 10953 (Sep 4, 2017)

hate to say it,but you just might be looking at checking the valve adjustment first as it sounds a lot like the ACR isn't releasing as designed 

i'm going through similar on a kohler twin today, when checking the compression i found sometimes it works, sometimes it won't .


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## EdwardC (Sep 26, 2016)

Thanks, powershift. I figured I'd end up needing to check the valves anyway. Might as well do some carb cleaning while I have it off, too bad it's not as easy to adjust as a newer OHV engine!


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## 10953 (Sep 4, 2017)

if you need to repower look at the motors from harbor tools, not bad for the price https://www.harborfreight.com/engin...hv-horizontal-shaft-gas-engine-epa-69730.html
as long as the cranks match your a go, just need to use longer bolts to hold it down to the tractor engine plate


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## 86trx250r (Oct 28, 2017)

I had a lawnmower do the same thing. I removed the spark plugs and pulled the starter rope, and a good amount of gas sprayed out the plug hole. Installed the plug and it fired right up. Don't know why it happened and it's been fine since. Give it a try hopefully it helps


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## Spectrum (Jan 6, 2013)

Another vote for restoring valve clearance


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## drmerdp (Feb 9, 2014)

It's likely the decompression mechanism. You would be looking at a tear down and replacing the cam.

The toro 521 is an excellent candidate for a Honda or predator engine swap. I did this on my 3521. Good stuff.

It's nearly a bolt on swap with the only curveball being modifying the chute crank rod with a universal joint or spacing the handle out a few inches.


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## EdwardC (Sep 26, 2016)

Thanks guys! I'll do the easy stuff, and will plan on a repower if necessary. The Predator is probably a great option, but for some reason, I really want to find a used Honda engine, either a GX160 or GX200. Maybe if I can find something off a blown pressure washer that has the right shaft. I'd probably even consider a GC160/190 if there was one cheap enough, I know they're not nearly as good as the GX or Predators. 

Thanks again, I'll make sure to report back if I find anything.


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## 10953 (Sep 4, 2017)

one more thing to try before going crazy, throw some heat at the block, get the oil warmed up. try to start it. if it does let it run till good and warm, change the oil to a 5w20 or 5w30,
i had a few that had straight 30w in them that made the ACR stick when cold."think stp when cold ??" a few changes to 5w20 and no more problems


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