Retainer keeps popping off intake valve spring on B&S 252707 11hp

[GBertolet]

I have a reoccuring issue with my lawn tractor. First it was the intake valve seat constantly comming loose. That was fixed, by staking the crap out of it. Now it's the intake valve spring retainer frequently popping off. I had already replaced the valve and retainer, but the issue still persists. Why does this keep happening, and how can I fix it?

 

[redline4]

I assume that it is the circular slip over style retainer?
If you want it trouble free, get a new valve, retainer cup and keepers, the new one should utilize split locks.
I can't recall if the spring is the same or not (height wise).

Most likely the valve tip is worn along with the retainer hole being enlarged is why it keeps failing.

I'm also not 100% sure if the valve we used to use for that was for that engine or from a different one we used...
Do some digging on heymow.com there should be everything under the flathead section there as they were used quite a bit for racing years ago.

 

[GBertolet]

The intake does have the slip on retainer. The exhaust valve has the two wedge type keepers. Are those type of keepers and retainer cup interchangable, with the slip over type valves? I was thinking that possibly the intake valve spring was weak, and was floating at higher rpms, causing this issue.

 

[srcarr52]

If it's slipping off the spring is probably weak and slinging off the retainer from spring surge.

 

[GBertolet]

I ordered a new intake spring. I will see if that fixes this issue.