free website stats program 1988 sportster Bad Crankshaft ... what now? HELP! | Page 4 | Harley Davidson Forums

1988 sportster Bad Crankshaft ... what now? HELP!

stray dog said:
Some one did some shoty engine work here.

Do you have adjustable push rods?

Is the stock cam in it?

What was the compression when you checked it?
Click to expand...


-I do have adjustable rods.
-Cams are Andrews
Can't remember the exact number for the compression but I was told it was within specs ...
 
My book says that the o rings should be fitted to the dowel pins prior to fitting the head gasket as the o ring helps centre the head gasket
Softail and dyna service manuals have similar wording
When HD redesigned the gasket to no longer use the o ring it would have been easier to get to grips with if a wee bit of info went in the box with the redesigned head gaskets
Both gaskets are correct the old ones need the o ring the newer style does not I am sure there will be a service bulletin that warns of the change of gasket style but most of us do not get them sent to us

Brian
 
fin_676 said:
My book says that the o rings should be fitted to the dowel pins prior to fitting the head gasket as the o ring helps centre the head gasket

Softail and dyna service manuals have similar wording

When HD redesigned the gasket to no longer use the o ring it would have been easier to get to grips with if a wee bit of info went in the box with the redesigned head gaskets

Both gaskets are correct the old ones need the o ring the newer style does not I am sure there will be a service bulletin that warns of the change of gasket style but most of us do not get them sent to us



Brian
Click to expand...


Ok... I guess that makes sense..
I just went by the parts catalog I had and it didn't mention any rings so I thought it was a mishap.

Other than that the valves taping the cylinder is/could be the reason for the noise I was having ?
 
Maustarman said:
Ok... I guess that makes sense..
I just went by the parts catalog I had and it didn't mention any rings so I thought it was a mishap.

Other than that the valves taping the cylinder is/could be the reason for the noise I was having ?
Click to expand...

Thanks to Brian for clearing up that gasket thing!

The valves hitting the pistons may be your problem ticking noise or one of a few problem noises. Your trusted mechanic doesn't like your crank....but did miss the valve to piston thing...?? That crank issue could be catastrophic if not addressed.

What Andrews cam is in it?
Are the pictures just showing the front piston and the exhaust valve hitting about .010 and the intake may or may not be hitting?
Having the pistons machined I think is one way to go or a thicker head gasket sacrificing a little compression.
Hopefully some others chime in here, and correct me if I'm wrong, this is getting above my pay grade :D
 
Brian is absolutely correct on the gasket/o ring issue. I would check your cams to see the lift on them. If they are Andrews you can go to their web site to check that out. They usually state as to whether or not Head work is needed. You may need some valve spacing done.
The rod bearing races are replaceable, along with rod/crank bearings. They usually need to be sized. I believe head gaskets can be purchased after market in 0.030 or 0.045 thickness. Maybe Dolt can add to this.
tourbox
 
Thank you everyone
This is awesome ! All this help and ideas.
I'm pretty handy but all this is new to me so, having all this information and advice is great.

I guess next thing is to figure out where to get thicker gaskets
 
Your Indy dealer should be able to get them. Drag Spec., Biker's Choice all sell them in complete engine kits, top end kits or individually. I usually get the kits because they are cheaper than buying piece mill.
tourbox
 
Ok... I decided to put the top end back together with a ticker compression gasket *Just to check if the sound was gone or not.
I figured out how to adjust the pushrods since they didn't have any markings or anything.
I just went out after letting the lifters bleed and double check the adjustments.
Started the bike and YES! The sound is gone :)
I check compression and I got:
230 PSI in the rear cylinder &
215 PSI in the front cylinder.
How do those numbers sound?

-------
Now, I'm having another problem here:
The bike only starts with the choke all the way out and when it starts its really high revs. Next- as soon as I disengage the choke the bike dies.
What did I do wrong- why is it doing that? (Used to start easily and idle nicely)
Is it Carb related, air leak some where?
 
Compression looks good, check for intake leaks and the boot that holds the carb on the manifold
 
You must log in or register to reply here.
Back
Top