Have a leak on the back of my rear cylinder base gasket. This is my first time doing this job!!! Any tips or tricks out there that can help me?? Or any certain brand gasket to use, also gonna get new rings and hone the cylinders!!

 

Spend the extra money and get Total Seal file to fit rings, either moly or cast iron. They keep the leak down very low and add a little extra power for your trouble.
John

 

Excuse my ignorance, John, but can you use these rings with any piston? Have heard of them over the years, but never knew anyone who used them. Always went with the crowd with Hastings. Ride safe,
Harold

 

I just finished mine today on a 91 FLSTC. It's an easy job but, labor intensive. My first advise is to buy good gaskets. I used James Base gaskets, Harley head and rocker box gaskets. I bought all the new top end rubber in a top end gasket set on ebay. Get the new Harley head gaskets. They eliminate the dowel o-rings. I was told by an old Harley mechanic that the James base gaskets are the best. They aren't cheap but, mine is now dry as a bone, so.. I'm happy. I would buy a top end gasket set as it will include all the O-rings and paper washers, etc.. Don't reuse any old rubber. Common sense. It gets dry, brittle and shrinks over the years. While your at the Harley shop get new piston wrist pin circlips. They are dirt cheap. Never reuse the old circlips.

The tear down took me four hours. I probably scraped gaskets for another four hours. Then the rebuild took a days work. I went slow because I didn't want to screw it up.

Now that I've done it I wouldn't hesitate to do it again. I took pictures with my phone just in case I forgot how things went back. But, I never used the pictures. I have red locktight but, didn't use a drop of it. I did use blue locktight in a few places. I also took my carb apart and cleaned it out before putting it back. That's probably why it took me a day to put my bike back together.

If you have any questions just ask. I have a service manual but, I only used it for the torque sequence.

Oh, get a real gasket scraper and don't screw around with razor blades. I used a gasket scraper I bought many years ago when I was an aircraft mechanic. Keep it sharp as you go and work at a shallow angle. the old base gasket's gonna be cooked on there so, get ready to work. But, don't gouge the aluminum. Just be patient with it. A real gasket scraper is a lot safer than razor blades to save your mating surfaces. I keep a file handy and every few minutes I give the scraper a few whacks to keep a sharp edge on it. If it get's dull you're more likely to gouge the aluminum because you'll have to increase the angle to get anything done. In my mind the hardest part of this job is scraping gaskets and saving the mating surfaces. It's boring, tedious, and critical that you get it right. Some people say use a wire brush on a drill. I'm not doing that because I feel like it can't help but remove metal. Yea, it's easier but, I don't trust it.

I left the pistons in the cylinders. It's super easy to just pull the circlips and replace them. If your bike has a lot of miles you may find that you will have to hone and re-ring. That's no a big deal either but will add a lot of time to getting back on the road. My bike has 26,000 miles and the cylinders looked perfect. Once you figure out the trick to getting the new circlips in it's not difficult. I bought four just in case I shot two across the garage. But, I didn't have any problems. I load one end into the grove and put a finger over the clip. I then used a screwdriver to push the rest of the clip in.

When you slide the cylinder back down into the case it will probably get hung up. That will be the gasket. I just lifted the gasket up a bit over the cylinder skirt, then set it down onto the case, gently. I oiled up my head bolts so they screwed in hand tight really easy. That's where the torque sequence starts. On my bike it was something like, 9 foot pounds, then 12-14 foot pounds, then a 90% final turn. It's good and tight but not quite gorilla tight. I market my head bolts to be darn sure I did exactly 90% on that final step.

My bike has an S&S carb. It's a good idea to install the plate on the front of the carb before tightening down the intake bolts on the heads completely. Or at least testing to be sure the angle is right. There is a bit of play there before you tighten them down. If the carb is angled too low then you'll be tearing stuff back off to re-set the angle on the carb to get that carb plate attached to the carb and the head mount points.

Lastly, when you reinstall the tanks make darn sure you've got all the hoses correct. Gas is dangerous, as you know. If yours has split tanks, like mine, then there will be a top crossover tube under the dash panel. Don't forget that one or when you stop for gas you'll get a surprise. Ask me how I know.

 

Total seal are available on-line or through major dealers like Ultima, etc. I would use the cast Iron for your application. WE use them exclusively and as I said before very low leak-down numbers and a few extra HP to boot. The can be purchased for any piston ring combination. Permatex make a spray on gasket remover that really softens up the gaskets so that you dont damage the aluminum. You may need to re apply it more than once for stubborn parts.
John

 

My 88 has the same leak. I did some research and found this product to be highly recommended. I thought I'd give it a try when the time comes.
http://www.haydensm6.com/tof_single.htm

 

Thank you for the info Very helpful!! Did u reuse your head studs and bolts??

 

Use Genuine James Silicone Bead Base Gaskets and you will never tear it down again for a weeping base gasket

 

My wrench will use nothing but the James base gaskets......he got 41 years working on these Harley's.

 

You can also use paint stripper, same chemical is used, just not in a spray can.