Ryobi 4-stroke engine problem

[muddy51]

Hi y'all.
I've got a Ryobi Model RY13016(T430) 4-stroke wheeled string trimmer. The rocker-arm stud for the exhaust valve has stripped on the engine head end
just enough that it will run a little while and then loosen the valve enough that it quits. Ryobi doesn't show replacement parts for inside the engine.
The threads in the head appear good. I've tried putting the stud in with red loctite with no success.
Anyone know who actually manufactured this engine or where I could find a replacement stud?
Maybe try blue loctite?
Some other idea?
I didn't want to try the blue loctite until I heard from y'all as it's somewhat permanent.
Thanks,
mud

 

[StarTech]

Ryobi (Homelite) unit. Only option from OEM is a short block.

I personally consider these 4 cycle units just junk and tell all my customers to avoid them.

You can clean and try Loctite Blue as it is a last ditch effort.

 

[sgkent]

I thought Loctite blue was softer than red, and green was the highest. That said, does the stud feel right torquing into the head? Is there room and angles to install a heli-coil or timesert?

 

[StarTech]

Try getting out screw under 6mm out that been red Loctited in place. Nearly every one will snap off.

 

[muddy51]

I was wrong in my original post. I had tried blue loctite which didn't hold but may try red next. The stud is only 3mm diameter.
Head is aluminum and stud is steel so I don't think it could be tack welded.
I wonder if epoxy glue would standup to the heat and vibration?
I'm retired so I got plenty of time to mess with it.
Thanks for all the suggestions.
mud

 

[sgkent]

red Loctite but clean the stud first. Double nut, Red Loctite, breathe on it to get some humidity on it, and tighten it just a little. Let it cure overnight, it won't come out.

 

[bertsmobile1]

I was wrong in my original post. I had tried blue loctite which didn't hold but may try red next. The stud is only 3mm diameter.
Head is aluminum and stud is steel so I don't think it could be tack welded.
I wonder if epoxy glue would standup to the heat and vibration?
I'm retired so I got plenty of time to mess with it.
Thanks for all the suggestions.
mud

No
Domestic epoxies have lower temperature ranges than loctite.
Silicons are more temperature resistant than epoxies
If it is pulling out that is because the casting was defective from the start or the engine is overheating

 

[Scrubcadet10]

have a look here, but i'm positive Star is right. https://www.ereplacementparts.com/r...heeled-trimmer-parts-c-7931_15633_290378.html

 

[muddy51]

Howdy Y'all,
I used the red loctite and it's working so far. I used the machine for about 30 minutes and it's working as it should. What was actually happening was
the rocker arm stud was backing out of the head. When the exhaust valve would get too tight it would quit running. I cleaned the stud and the threaded hole
in the head with brake cleaner, applied loctite to the stud and screwed it into the head. The stud is only 3mm dia. thd so can't put too much torque on it. I let it sit for 24 hours and then reassembled and adjusted the valves.
Next time it quits I'm gonna set it out by the road. Thanks for all the ideas and suggestions.
mud

 

[oneoldsap]

Hi y'all.
I've got a Ryobi Model RY13016(T430) 4-stroke wheeled string trimmer. The rocker-arm stud for the exhaust valve has stripped on the engine head end
just enough that it will run a little while and then loosen the valve enough that it quits. Ryobi doesn't show replacement parts for inside the engine.
The threads in the head appear good. I've tried putting the stud in with red loctite with no success.
Anyone know who actually manufactured this engine or where I could find a replacement stud?
Maybe try blue loctite?
Some other idea?
I didn't want to try the blue loctite until I heard from y'all as it's somewhat permanent.
Thanks,
mud