Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles Bent Valve ?

Bent Valve ?

Post Thu Jul 12, 2012 8:33 pm

Posts: 309
Location: Cranbrook B.C. Canada
The knuck started missing ,so I managed to limp it home.I kicked it over ,it has zero frt.cyl. I checked valve adj. frt ex.push rod is loose and it won`t adjust ,threaded adjuster is all the way out of tappet and it doesn`t touch pushrod. Valve must be bent ,I`ll do a leakdown tomorrow.
Then I`ll pull both heads and check everything on both heads.
I also removed the top tins from both rocker covers on frt.head..
I can`t detect any endplay on rocker shafts and frt.rocker is very stiff .I have to pry it with screwdriver to make it move up and down away from spring retainer.
I know that rubber seal gives it some resistance ,but this is extremely tight.
Pushrods are not bent ,and rollers on tappets are good.
Maybe this caused a valve to stick ? Also maybe valve too tight in guide?
Any ideas ?
Thanks in advance.

Post Mon Jul 16, 2012 11:01 pm

Posts: 309
Location: Cranbrook B.C. Canada
I finally got a chance to work on my Knuck ,I removed the frt.head tonite ,someone installed new valves ,and guides and new rocker shafts ,seems to be no clearance on and valve is seized in guide ,partly stuck open. Had to drift it out with a hammer.
Intake valve is not seized ,but is very tight with not very much clearance.
After I get this all sorted out ,I will be checking the rear head as well.

Post Tue Jul 17, 2012 9:45 am

Posts: 2688
Location: Los Angeles, CA
Who built the heads? Hopefully they are cast iron guides.

Post Tue Jul 17, 2012 7:15 pm

Posts: 309
Location: Cranbrook B.C. Canada
Not sure who built the heads ,Previous owner had a reputable expert build the engine . Maybe he was an expert on Evo`s or something other than Knucks ?
Yes ,they are cast iron guides .

Post Tue Jul 17, 2012 10:05 pm

Posts: 2688
Location: Los Angeles, CA
Sounds like something easily fixed with a guide reamer.

Post Thu Jul 19, 2012 3:12 pm

Posts: 219
Location: Georgia
I have been running Kibblewhite bronze guides. Guides have about 15000 miles. They seem to work OK. What problems are associated with them?

Post Sun Aug 12, 2012 10:35 pm

Posts: 309
Location: Cranbrook B.C. Canada
Just an update on my seized valve;
I took both heads apart ,honed the guides to proper clearance ,replaced one valve and set up the rocker arm end-play.
I been riding it for a couple weeks now ,it starts good and runs nice and has good power on the highway.
I`m real happy with it ,It`s a keeper!

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