Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Vintage Royal Enfield => Topic started by: High On Octane on May 20, 2013, 01:34:19 am

Title: ACE & ERC! I Need Your Immediate Help!
Post by: High On Octane on May 20, 2013, 01:34:19 am
I got bad news boys.    :(    I replaced the intake gaskets last night and this morning the bike started up great and was sounding fantastic.  Went out for a ride and everything was good to go.  Then on a straight stretch I was getting on it and the little chirping noise that I had been hearing turned into an obnoxious popping sound.  I pulled over to see where the noise was coming from and it was quite obvious that I blew the head gaskets on both cylinders.  Puffs of smoke coming from in between where the head meets the cylinder, plus I can see an oily seepage coming from the same area.    >:(

Here's where I need your guys' opinions.  I'm not ready to do a full tear down at this time as the riding season JUST started.  Basically I need to know if I can get away with just replacing the head gasket, or if I should pull and hone the cylinders, re-ring the pistons and replace the base AND head gaskets.  If I pull the cylinders, I'm very inclined to replace the pistons with the standard 8:1 compression pistons and keep the same bore for now.  I don't know.  I do know I'll make sure to do a full decarbonizing of the heads and also grind the valve seats while I'm in there.  Is there any other hardware or replacements parts or procedures that should be addressed while I'm in there?  Also if anyone has the torque specs for the head bolts it would be greatly appreciated.  I don't want to spend too much time or money right now as I'm going to do a full rebuild this winter.  Thanks!

Scottie
Title: Re: ACE & ERC! I Need Your Immediate Help!
Post by: ace.cafe on May 20, 2013, 01:37:58 am
I don't know.
It's best to pull the heads and see what's going on.
Both head gaskets normally don't blow without any cause, so it needs some investigation.

Pull the heads and post up some pics of the innards.
Title: Re: ACE & ERC! I Need Your Immediate Help!
Post by: High On Octane on May 20, 2013, 01:44:13 am
The left cylinder is more leaking than blown.  It was only the right cylinder that I actually noticed smoke coming out of.

Let me ask you this.  Is a small amount of oil seepage out of the base gasket doing anything other than leaking oil?  Does it have any effect on the compression of the cylinder?

Scottie
Title: Re: ACE & ERC! I Need Your Immediate Help!
Post by: ace.cafe on May 20, 2013, 01:50:49 am
The left cylinder is more leaking than blown.  It was only the right cylinder that I actually noticed smoke coming out of.

Let me ask you this.  Is a small amount of oil seepage out of the base gasket doing anything other than leaking oil?  Does it have any effect on the compression of the cylinder?

Scottie

There are various possibilities.
One possibility is a holed piston, which would dramatically increase crankcase pressure, causing smoke and oil leaks to push out wherever they can. So in that case, there would be a very big decrease of compression, and a lot of crankcase pressure.
Another possibility is just a blown head gasket, with the gasket blown between the compression seal and the pushrod tunnels. This would lose compression in that cylinder, and cause oil leaks and possibly smoke to come out anywhere they could too.

High crankcase pressure causes oil leaks to start happening, and the base gasket could be leaking because of that.

We don't really know what happened until you get the heads off to look at it.
You need to replace the head gaskets anyway, so the heads have to come off.
Show us some pics.
Title: Re: ACE & ERC! I Need Your Immediate Help!
Post by: High On Octane on May 20, 2013, 01:56:00 am
All righty then!  Out to the garage I go!  I gotta get cracking here, it's been in the 80's out here in Denver and I'm sick of driving my POS truck.  It needs a new motor too.  And shocks.  And front end.  And computer.

Scottie
Title: Re: ACE & ERC! I Need Your Immediate Help!
Post by: ERC on May 20, 2013, 01:44:53 pm
You may be better off pulling the jugs off and checking like Ace says. The base gaskets are cheap and your almost there. When you put the jugs back on use 2 gaskets with sealer.   ERC