A few weeks ago I bought a top-end kit to address the leaky base and rocker box gaskets on my '90 FLHS, which I bought new in June 1990 at Harley Davidson of Baltimore. This past Xmas, my son gifted me a new camshaft, a VThunder 3010, so time to get after it, replace the gaskets, install the cam, &c. I do have a FSM.

90 FLHS, 22K unabused miles (about 814 miles/year...I know, I know).







No real issues with the teardown. Heads came off without incident.



I left the pistons in the cylinders. The rear piston pin came out easy. The front piston pin was tight in the skirt. I had to tap it out with a brass drift and plastic hammer.

Had one cylinder stud come out, rear cylinder, left rear stud. This was the location with the biggest base gasket oil weep. Fortunately, the stud wasn't pulled and both the case and stud threads looked OK. I cleaned up the threads and reinstalled the stud with red loctite.





Both base gaskets were somewhat damp with oil, which made gasket removal easy. It took me less than 5 mins to clean the gasket material from the case and cylinders. Most of it came off with a pink shop rag. I used a plastic scraper to remove the stubborn parts. Rocker box gaskets came off easy as well with about 15 minutes of effort.

Front Cylinder gaskets



Rear cylinder gaskets



Cam chest. The cam bearing is marked Torrington (the 'good' bearing).



As I planned to use the old cam gear on the new cam, I first marked the old gear. As the gear is hardened, I used a blue sharpie to highlight the area to be marked and scribed through the blue. We can see some wear on the lobes of this 22K mile cam.



New Cam



New Cam, old gear installed.



Unfortunately, I did find two time bombs during disassembly, both with the exhaust.

First there is a crack in the rear exhaust header Y-pipe. The crack is in the tube as well as along the weld. Can this be successfully repaired/welded? Should I even bother?



My FLHS has the flanged exhaust and mufflers. Upon removing the left muffler, I found that the flange at the muffler on the left exhaust pipe had rusted and most of it fractured away. I last had this muffler off about a decade ago. It would be nice to find a way to repair this, as I'm running some mid-late 90s SE slip-on mufflers that I like.



The piston tops and combustion chambers have a coat of hard carbon. Should I attempt to clean this off? Any harm in leaving it?

Things are on hiatus right waiting on parts and for temperatures to rise. Gives me time to think about the exhaust and carb jetting. I don't plan to change up the ignition right now.

 

I lost the Y-pipe on my '90 as well. I didn't catch mine until it came completely apart.

I was in the same boat as you, since I had some flange-type mufflers I wanted to keep. I ended up getting a new set of true-dual headers from Paughco.

All the gory details are in this thread.

 

I think you will like that cam. Its the same one I installed in my EVO road king. Even though you have the "good bearing" I'd stick a new one in anyway... Good luck with the project. Glad you didnt have to much trouble getting the base gaskets off. Mine were fused on like Iron!

 

Thanks. I've read your posts and your experiences influenced my selection of the 3010. My project plan plan includes new cam bearing, new lifters, .030 head gasket, and now, perhaps, an exhaust change/upgrade. Just waiting on the weather to warm up a bit. My garage is unheated, and while I have a good kerosene heater, with the current single/low double-digit temps, I can't get it above 40. I don't want to fit and torque my now frozen engine parts.

BTW, You have a great looking scooter. I'm sure it runs just as well.

 

I'm sure don't need to tell you but I had only 6 thousands clearance on the rear cam lobe to the case. Make sure you check that.. Thanks for the compliment on my King..

 

Interesting. I measured the old and new cams and found the new cam was about .045 longer, excluding the cam lock washer. The stock cam had no shim, just the lock washer. Did you get .006 without a cam shim? What cam gear gasket did you use? I plan on running a Cometic steel. Thanks again for your input. It really helps.

 

Is it me, or does the "original cam" look to have more duration then an "original cam"..
Here's an N grind OEM cam.. I don't know maybe I'm wrong and the pictures does not show the lobe as seen with the baked eye...

 

I'm not talking about end play. slide the new cam in and make sure it spins around with out hitting the case on the inner lobe. Also Bob his stock cam should have been an L and not a N





OTE=RGranville;16967635]Interesting. I measured the old and new cams and found the new cam was about .045 longer, excluding the cam lock washer. The stock cam had no shim, just the lock washer. Did you get .006 without a cam shim? What cam gear gasket did you use? I plan on running a Cometic steel. Thanks again for your input. It really helps.[/QUOTE]

 

Aha. I understand now. Hopefully it won't be a problem; you're right that the OEM cam is an L grind.

 

Hi Rob, fellow 1990 Hi Fi Candy Blue FLHS owner here, also bought new. Cylinder base gaskets were a known problem and I replaced mine at a roughly similar mileage to your bike. My exhaust also cracked like yours, although I chanced on a near new replacement at the time. You can install any exhaust you fancy for bikes up to 2008 without problems, so a later set of stock pipes will be fine. That odd flange type of pipe-to-muffler set-up was dropped mid-90s, which allows us to use any aftermarket brand.