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1997 Road King
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Discussion Starter · #1 ·
Hi all, I'm new to this forum and have landed here, like many others, with a problem. Some brief history:
I bought this 97 Road King in July of 2019. It has 32k on it and supposedly someone had done some engine work to it at one time (this will come into play in a bit). In late fall 2020 it started to have the telltale valve seal problem of burning oil on fire up. It got worse... quickly. Okay, no problem, I can do valve seals. Tore it down in-frame and sure enough, valve seals are crumbling. Popped the jugs to do base gaskets and noticed the piston ring gaps are all 100% in line. Ugh... okay. Pulled the pistons (stock slugs), cleaned everything up and clocked the ring gaps properly. Put it all back together and she runs great with no more oil burn on fire up. Yay, success, except.....

On fire up, even the most minute crack of the throttle causes blowby out the rear pushtube of the rear jug. It does this for a few minutes after starting and then goes away... mostly. I always let it warm up for a couple minutes before riding, it doesn't leak a drop of oil out that pushrod tube. It has the Mikuni TM42-6 carb with a K&N adapter, the head breathers are plumbed into the air filter base. The disturbing part is that it didn't do this before I put valve seals in it so clearly it's something I did wrong but I'm at a loss as to what.

Anyone able to reach into their archives and give me a clue as to what I screwed up? Greatly appreciated.

Rob
 

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1997 Road King
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6 Posts
Discussion Starter · #3 ·
"Breather gear out of time in the cam chest?"

Hi Kouack,
Thanks for the reply. I was wondering about that in my initial "research" into this a year ago. I am just not sure why it would have started only after doing valve seals and gaskets. I didn't remove or touch anything in the cam chest so I brushed it off at the time. Is there something I could have done while doing the valve seals and jug gaskets to cause the breather gear timing to be wrong? My knowledge here is pretty low and I'm more than willing to learn what I don't know.

Thanks,
Rob
 

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Retired citizen
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25,593 Posts
Breather gear out of time in the cam chest?
1 tooth will do it ! But only 1 pushrod tube ? The breather gear affects both cylinders.
New piston rings ? Ring upside down ? Naw the blowby wouldn't go away after a few minutes.

OK, a 25 year old Road King with 32K (original ?) on the clock, hmmm ! The only problem seems to be a slight blowby from the rear pushrod tube on startup but no oil leakage ! Am I missing anything here yet ? I'm assuming the OP is seeing this blowby from the rear cylinder at start up from the rear head breather port. Otherwise where else ?
 

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1997 Road King
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Discussion Starter · #6 ·
"OK, a 25 year old Road King with 32K (original ?) on the clock, hmmm ! The only problem seems to be a slight blowby from the rear pushrod tube on startup but no oil leakage ! Am I missing anything here yet ? I'm assuming the OP is seeing this blowby from the rear cylinder at start up from the rear head breather port. Otherwise where else ?"

Hi SCHMIDTY,
Yes, that is all correct, except this isn't a slight blowby. This is a pretty substantial pop coming out of the half-moon cutout on the pushrod tube cover. It really reminds me of if an exhaust gasket were missing, except not coming from the exhaust. I originally thought it was coming from the cylinder head vent port, but I wrapped the pushrod tube in a piece of paper and it popped a hole right through it, so that is definitely where the problem is.
 

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1997 Road King
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Discussion Starter · #7 ·
"Bad head gasket?"

Candyman... problem solved. I am quite the idiot here. The head gasket is blown directly behind the pushrod tube making it look, feel, and act like that's where it is coming from. Right down to shredding the paper I used by blowing compression into the shield and out the half moon. So looks like I'm going to order gaskets and then eat some humble pie.

Thanks all for the help, I knew it had to be something I did.

Rob
 

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Just Ride
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4,045 Posts
Roger read the whole post. Head gasket blown behind tubes. Oring placement had nothing to do with it.
 

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1997 Road King
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Discussion Starter · #12 ·
Kouack,
Not sure I've ever considered a blown head gasket a happy ending. But considering what it could have been, I'll take it. Simple enough fix. Gaskets will be here Monday, should take about 4 hours or so. Hopefully be up and running by next weekend.
 

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nitro freak
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1,290 Posts
better hope your not pulling a stud out of the case,i assume you took the head off to replace valve seals.
 

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1997 Road King
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Discussion Starter · #14 ·
Right? That would suck. I'm optimistic since it came apart just fine last time, but that doesn't necessarily mean squat. Yeah, it all started with valve seals.
 
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