• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

So I guess I?m replacing the head

  • Thread starter Thread starter Dan
  • Start date Start date
D

Dan

Guest
More than I anticipated doing on this bike but there are 6 broken exhaust bolts in the thing. I spent about 3 hours trying to clear one of them with little success. They are seized up hard. Went thru all the tips on the forum about bolts and tools and I?m moving on. I?ll feel better about the bike anyway once I know what?s in there, especially given some of the things I?ve come across from the PO.

So 1. If the site has a thread or tips on the process, please share. This is my first one.
2. Any gotchas I need to know about, also please share.

Thanks
 
A machine shop can extract the bolts. In terms of DYI, I've had good success using LH drill bits, but doing 6 will try patience.
 
Thanks Ed. I tried the LH bits, extractors, torch, penetrating spray, voodoo curses. I'll look around some at machine shops too. Dan
 
Harbor freight has a cheap LH bit set. Start with one of the smallest sizes and center punch the bolt before drilling. If you are off center work the bit sideways a little and get in the center as you step up the size. Slowly, one size then the next, being sure to work towards the center and then stay there as the bit size grows. Eventually you will be near full diameter of the broken screw and when the screw is just a shell it will grab on the bit and spin out. Works every time as long as you are careful.
 
Find a good TIG welder. I have one local to me who can weld a bolt with a point on the end onto a broken bolt or stud - so long as the end is visible.
The heat of the weld expands the aluminium away from the broken piece and it simply winds out...

He must have done over a hundred for me over the years now.
 
Thanks for the tips. Some of the breaks are beneath the surface. If the threads are damaged am I looking at helicoil or is that a bad idea?
 
Ok - decision time.

In addition to several broken exhaust bolts, I've found that the PO had tried to drill out one of them to the point that the hole is now larger than the bolt so a bolt just slides in and out of it. It will need helicoil, if it's salvageable at all.

I now see at least 1 intake screw broken, and several others that look completely rusted in place and are likely to break.

I am having no luck getting any of these out. Prior post about that misadventure.

I don't have the ability to take the complete bike to a shop. I was considering buying a new (used) head with valves already in place.

Valve cover is off. Actually pleased with the appearance of the cams from what I can see (photo below.)

So it seems I can either...

(1) continue was planned, pull the head, find a new head w valves, replace.
(2) pull the engine, take it to a shop for the bolt/helicoil problem.

I'm a bit intimated by taking the head off, but that's where I'm leaning.
I'm also intimidated by pulling the engine, since I'm doing this alone and I'm fond of hernias.

Any thoughts would be appreciated. Thanks


IMG_6099.jpg
 
You don't need to pull the engine to pull the head.
But, when you pull the head, pull the barrels and replace the base gasket and the two O rings

Many people replace those exhaust bolts with studs.
You can Helicoil that one bad hole, but a threadcert would be better.

I will advise you that you probably will find more Previous Owner Syndrome as you go thru the bike
 
You were right. I found other PO issues, including what looks like household silicone applied around the base gasket. This in addition to a wood screw holding on an exhaust pipe, which I posted about on another thread.

Pulled the head. Will pull the barrels to get to the base gasket and replace that, but I've never done that. A couple of questions -
Does that lower unit just lift up? It looks like it's held in place by the same studs as the head?
What happens to the pistons when I do that? I assume they stay attached to the camshaft, but how do I get the lower unit back on given the rings?
Newbie questions I know but I've looked around and I don't see a procedure.

Thanks, Dan
 
Yes, the cylinder barrel pulls up on off.
Hopefully, the rods and pistons are attached to the crank shaft.

There are several techniques for getting the barrels back over the pistons. I prefer some wood blocks and hose clamps.

You downloaded a service manual yet?
 
Thanks, the rods and pistons appear to work as I manually turn the engine.
I have downloaded a service manual but haven't dug into it yet. Thanks for the suggestion. I'll focus on reassembly after I clean up everything.

Here's a shot of the silicone job. Goes around the whole base, but it didn't stop an oil leak from the front.

IMG_6118.jpg
 
That bunch of slop is someone's feeble attempt to put a cheap gasket on and yes, it's useless. Although they are expensive, I recommend buying the proper OEM head and base gaskets and ensuring everything is set correctly. You will want to use wood blocks to support the pistons when installing the head - there are threads here about using them and I will try to to see if I have any pictures otherwise I'll get some this weekend.
 
You may luck out and find that all of that silicone is external.

Just when you think you've seen it all
 
There are several techniques for getting the barrels back over the pistons. I prefer some wood blocks and hose clamps.

You will want to use wood blocks to support the pistons when installing the head - there are threads here about using them and I will try to to see if I have any pictures otherwise I'll get some this weekend.
Here is what is pictured in the Clymer 850 manual:

Pistonholder.jpg

Not so sure that those dimensions actually work, you have to measure between the studs to make sure it fits between them.

I have never bothered with hose clamps. The bottoms of the cylinders are tapered/beveled, so simply squeezing the rings with your fingers will be enough to shrink them down enough for the cylinder to slide down. It is a test of patience, though, as you need to start with the top ring on #2, then go to the other side of the bike to do the top ring on #3. Continue with the second ring on #3, then back to the other side of the bike to get the second ring on #2. Continue with the oil rings on #2 and go to the other side of the bike to get the oil rings on #3. It helps considerably if you have someone helping you with this, but it's still a test of patience.

.
 
I found it a lot easier to just use hose clamps on two and three but have them just barely snug enough so that you can tap the top of the piston down until the rings are all in the bores. Just takes a little bit of patience.
 
The pistons are off. I think they look terrible but maybe you guys know better. It does appear most of the carbon comes off fairly easily, but I haven't gotten into it yet.

https://photos.app.goo.gl/UkYCvtPvVWEXEFc26

That's just carbon. What matters is what wear marks (if any) are on the sides of the pistons and in the bores. You'll need to invest in a set of digital calipers and some bore gauges - both of which are available cheaply enough to provide some measure of reassurance. Mostly, the cheap ones are accurate enough to work with, but there are some lemons out there. Iow, it needn't cost a lot to know exactly where you stand with it. Chances are, if the pistons and bores look undamaged, you will get away with a simple hone and new rings, but you won't know for sure unless you measure them up.
 
Thanks Dave, the pistons and walls look good, at least to me. I'll confirm the measurements and get the rings.
 
Back
Top