HarleyTechTalk

Technical Forums => EVO 1340 => Topic started by: fleetmechanic on December 10, 2020, 04:06:11 PM

Title: Bent pushrod
Post by: fleetmechanic on December 10, 2020, 04:06:11 PM
1998 Police Road King that we've let set for many years.  Put a new battery in yesterday and got it to fire and run with the enrichener full on for several minutes.
Today I pulled the idle jet out of the carb and cleaned the oriifice and then tried to start it up with a clean idle jet.  Terrible clatter and then noticed the rear intake pushrod was bent and bulging out of it's tube.   Does it make sense that a valve might have seized while cooling off overnight?
Title: Re: Bent pushrod
Post by: thumper 823 on December 10, 2020, 05:01:19 PM
If it bent a valve it's bent!
- No going back, SOoo try another Push Rod and see what happens.
Or TDC On compression,  it and do a leak dwn.
Title: Re: Bent pushrod
Post by: Hillside Motorcycle on December 11, 2020, 04:14:37 AM
Pull the head, and inspect the cam chest also.
Title: Re: Bent pushrod
Post by: JW113 on December 11, 2020, 02:26:21 PM
Quote from: fleetmechanic on December 10, 2020, 04:06:11 PM
Does it make sense that a valve might have seized while cooling off overnight?

Can't imagine how that could be, but what do I know? If the motor was shut off with the rear exhaust tappet up on the nose of the lobe, it's possible the tappet bleed down, got stuck and is now collapsed. So when you fired it up, the pushrod just rattled around in there until it bent.

:nix:

-JW
Title: Re: Bent pushrod
Post by: Ohio HD on December 11, 2020, 03:51:10 PM
The roller on the lifter could have left the building. Then the push rod was hammered.    :nix: 
Title: Re: Bent pushrod
Post by: thumper 823 on December 27, 2020, 09:01:36 AM
Did ya pull the lifter and look at it?
Title: Re: Bent pushrod
Post by: fleetmechanic on December 28, 2020, 09:52:29 AM
This one is on the To Do list.  I'll post as soon as I get into it.
Title: Re: Bent pushrod
Post by: fleetmechanic on January 30, 2021, 03:32:10 PM
Well I got a round tuit and went digging for an answer.  Removed the rear head which looked OK inside and pulled the tappet block where lifters and the cam lobes also looked fine.   Then I removed the intake valve springs and had to use a drift and a hammer to get the valve to move.  Stem looks OK and can't see any bending but I ordered a new valve through Vintage Parts and we'll see how it fits.
Title: Re: Bent pushrod
Post by: thumper 823 on January 30, 2021, 06:38:22 PM
slippery slope.......what is the guide material?

More than likely all the guides will need replacing anyway....
And if you check all the valves you will probably find they all have the same issue?
I will say you are headed for a valve job .
Check your pinon drive gear too!
Title: Re: Bent pushrod
Post by: Hillside Motorcycle on February 01, 2021, 03:46:59 AM
Clean/prep/inspect both heads, and set valve/stem dimensions accordingly.
When remove/replace any guide, a valve job is guaranteed.
Title: Re: Bent pushrod
Post by: fleetmechanic on March 19, 2021, 09:04:35 AM
Installed a new rear intake valve and guide seal, new pushrod and upper and lower tubes and the bike runs just fine.
Photos of the valve and pushrod.  When valve stem is rolled along the edge of a desk there is a slight wobble.
Title: Re: Bent pushrod
Post by: SP33DY on March 20, 2021, 09:44:34 AM
Starting an engine on very old gasoline that has varnished up has been known to stick a valve.