8252 has bright spark, clean carb, etc.. won't start!

[turfboy1997]

If the spark is not at the right time on the up stroke it will not run or run poorly or fire out the carb. so its a timing issue if you ask me, so the first place i would go is that flywheel key being sheared or a loose bolt on the flywheel.

 

[jameshobbs]

electrical is good

Do not forget to clean and check the exhaust ports ! If they are plugged up it can cause loss of power and will not start in extreme plugged cases

 

[peteclark3]

If the spark is not at the right time on the up stroke it will not run or run poorly or fire out the carb. so its a timing issue if you ask me, so the first place i would go is that flywheel key being sheared or a loose bolt on the flywheel.

Hmm so wait a sec (yes I'm still working on this with my son trying to get it running!!). So it's possible it could have spark but be sparking at the wrong time on this mower? (lawn boy 8252) .. I thought if it sparked then I automatically meant the timing was good. It shocks me because I sprayed starting fluid even in the cylinder and tried drill starting it and couldn't get a single fire out of it. It's nuts! I even made a spark test video for anyone willing to look and help...

Lawn Boy 8252 Spark Test - YouTube

I think the flywheel key is fine but ill check tomorrow. It doesn't seem like its possible to assemble the stuff under the flywheel incorrectly such that the timing is off.. Seems like everything only fits one way. I can't give up on this mower.. It's one of my son's favorites! He's 9.. Even wondering if someone would remotely troubleshoot this with me over FaceTime.. I'd pay!

Pete

 

[Rivets]

Go to the website below and use the manuals which cover D-400 engines. Your unit is a model D-481, if I have done my research properly.

https://lookup3.toro.com/ttcGateway/acrobat/manuals/lball.html

 

[peteclark3]

Yeah, I have this on my iPad and have been through it at least twice.. Still can't figure it out, let me know on the timing question above if someone can.

 

[jameshobbs]

Check your reed plate ( behind the carb,plate inside the engine ) they should be flat against the plate and sealing, If "open" or not sealing they can not do there job ( like a intake valve on a 4-stroke ) ?
Also check the exhaust ports if they are clogged it will not start or have little or no power ?
Hope this helps I have had a reed plate and / or clogged exhaust ports drive me crazy !!
and as my kids say " that's a pretty short drive ant'i dad ? "

Good luck !
Randy

 

[peteclark3]

Thanks.. Just checked the reed plate today and they were open a bit, so I bent them ever so slightly and now they are closed. Exhaust ports are open, cleaned the muffler a while ago as possible cause. What about the timing question above, is it possible to get a spark, but at the wrong time, on this engine?

It got in this non starting condition after I replaced the crank seal, which I did because it was not running very well and it's something my son thought we should do.. Does this offer any additional clues?

 

[jameshobbs]

I would replace the reed plate they are cheep and very,very easy to bend to much ! ( they only go one way !!! ) " maybe 5 bucks ?" There is not anyway the new bottom seal is upside down and /or not sealing ? tore or damaged ? The engine has to be able to hold a vacuum for the reed plate to be allowed to suck it open and closed If it does not it wont start. Also check to top crank seal too it could be shot if the bottom one was ?
How much compression does the engine have ? ? do a compression test remove the spark plug and install the tester some you will have to hold in the spark plug hole others you just screw in. crank the engine a few times and see what reading you get you want at LEAST 90 PSI if its below that the engine will not run on low compression low compression could mean a stuck or broke ring scored the cylinder wall ?

While you have the flywheel off look at and check the key way and key closely no dings of dents that is what sets the timing. When you put the flywheel back on look at the air gap between the The C-D (Capacitor Discharge) and the flywheel Insert .010 non-metallic gauge between C-D pack and magnets on the flywheel. this site helps explain the timing of the D engine and the c.D pack https://lookup3.toro.com/ttcGateway/acrobat/manuals/lball25.pd
Hope this helps ?
Randy

 

[turfboy1997]

From your youtube video the spark looks intermittent to me. When you had that drill on it as fast as you were spinning it that thing should have been snapping and blue. the spark looks orangeish to me. I had a electric start driving be crazy with a weak spark an the spark plug wire had a small cut in it causing it to ground out every once and a while. changed the wire and new cj14 spark plug and was good as new. check that too. The spark should be hotter than that in my opinion. I would try a different plug. every mower that i have gotten this year with those E plugs i have changed to a champion cj14. Let me know what you come up with.

 

[peteclark3]

From your youtube video the spark looks intermittent to me. When you had that drill on it as fast as you were spinning it that thing should have been snapping and blue. the spark looks orangeish to me. I had a electric start driving be crazy with a weak spark an the spark plug wire had a small cut in it causing it to ground out every once and a while. changed the wire and new cj14 spark plug and was good as new. check that too. The spark should be hotter than that in my opinion. I would try a different plug. every mower that i have gotten this year with those E plugs i have changed to a champion cj14. Let me know what you come up with.

Cool, thanks for that.. finally something I can check on the electrical. Will do for sure. I'll check all the wires..