View Full Version : Bent / wqarped intake valve?
tri again
04-13-2012, 07:14 AM
Not sure where to post this but it's an 18hp
Briggs twin ride a mow engine.
and one intake valve is slightly bent.
It's a flathead design so nothing to hit it, no real carbon buildup on the head and
the other cylinder is perfect so it didn't suck a chunk of water or anything obvious.
Exhaust valve is perfect.
Simply strange, or I'm missing something.
Thanks
atc007
04-13-2012, 09:23 AM
Quite common. Pull er out,do a valve job. Adjust them ,new head gasket ,and off to the races again. Briggs has become complete garbage in my mind. When I went to tech school in 87-88. They were king ,Tecumseh were considered inferior. now,,,EVERY single solitary Briggs twin I see is puking oil from the sump gasket. Should be a worldwide recall like the Raptor one way bearings... Anyhow! Was she shooting fire??!! Usually they will start and run w the valve slightly bent and shoot flames before they quit!
tri again
04-14-2012, 04:26 AM
Quite common. Pull er out,do a valve job. Adjust them ,new head gasket ,and off to the races again. Briggs has become complete garbage in my mind. When I went to tech school in 87-88. They were king ,Tecumseh were considered inferior. now,,,EVERY single solitary Briggs twin I see is puking oil from the sump gasket. Should be a worldwide recall like the Raptor one way bearings... Anyhow! Was she shooting fire??!! Usually they will start and run w the valve slightly bent and shoot flames before they quit!
aaah, GF with 2 teenaged boys run it so lord only knows.
But nice to know it a design flaw and not anyone's neglect or fault.
I didn't get to see it's last moments, just the aftermath.
Maybe I'll buy 2 exhausts valves just to have around for next time.
I guess the old briggs V twins had quite a history of upgrading for drag racing.
so parts should be easy to find, I hope.
Thanks 00
Dirtcrasher
04-15-2012, 10:40 PM
The worst thing they did was similar to the 200X cam.
They ran the crank steel on aluminum; And even if you keep the oil full, guess who wins.
Then they won't start hot OR cold. Glad I threw out all my B and S motors, guys loved the scrap and I loved the eyesore going away.....
atc007
04-16-2012, 07:34 AM
It just hit me that the inherant problem with these was, the ex valve seat pulls out of the block! That was it. Clean everything up,lock tite it / or the new one back in ,and peen around the edges to hold it. Is that what you found?
tri again
04-21-2012, 01:50 AM
It just hit me that the inherant problem with these was, the ex valve seat pulls out of the block! That was it. Clean everything up,lock tite it / or the new one back in ,and peen around the edges to hold it. Is that what you found?
Yeah, this was the intake valve simply bent/warped a little but the other cylinder compression tested perfectly.
The neighborhood small engine guy did it.
Needs work so I try to buy from them whenever I can.
I understand that a centerpunch in the right place can help hold in valve seats, if that's
what you were referring to.
I had a random thought.
It seems that people sometimes run a ride mower or other air (fan) cooled
stuff at less than 'bunnyrabbit' throttle and I guess they can overheat.
I actually read my manual and they said to always run (work) them at full T.
but idle slow for a minute or so before and after working them.
atc007
04-21-2012, 07:16 AM
Exactly on the punch idea. Holds em right in there. I too just farmed a big POS Briggs out to a friend who needs work. Craftsmans Top of the line. Briggs V twin. He called me on the phone{ neighbor} Said his hydros all out of adjustment and he has a huge oil leak. I said your sump gaskets puking...it is,some loose bolts visible. What a POS. I washed my hands of it!! My buddy,who was a Suzuki/Cat/ Simplicity dealer for 30 years,said that briggs,for 10+ years??? Had a bad torque wrench on the assembly line. And these sump bolts are to be torqued @ 200 w locktight. The factory was shipping them @ 120,dry. Either way,,I don't want any on their stuff around : ) Glad your back under power!
300rman
04-21-2012, 09:39 AM
And these sump bolts are to be torqued @ 200 w locktight
200 what? Surely not foot-pounds?
This is what happens when China gets all the work :/
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