Ok. I guess I am sticking with the stock pistons. What about plugs. I hear good and bad things about the pulstar. But I have not talked to anybody that has used them on a evo. Anybody have any experience with them?

 

I'm going to break tradition a bit on this one.. I've got 9.25:1 pistons in mine, but I have a cam that likes that. The missing peice of the puzzle you have above is the cam.. If you are changing the cam, I think you'd be leaving alot of power on the table with stock pistons, more in relation to compression than material.. But, that all depends on the cam. Some work well with stock compression and some dont.. It all depends on your ultimate goal.. But, if you just want to do base gaskets and no cam, I agree with the guys above and forget the pistons..

On ignition parts, I've become very suspect of wiz bang parts.. I use Champions in my bikes. Thats what they were born with and thats what seems to do me well. In the auto world, I've thrown away more brand new $10 plugs than I can count because they cause missfires. Aftermarket is not always designed to work in your specific application.. So, unless you're making other changes, save the money..

 

Oh boy... To simply answer your question: No. Pull the tank and start removing stuff.

Now.... Depending on the number of miles on the bike, I would only pull the jugs up far enough to remove the rod from the pistons. Get the cylinders mic'd and checked for roundness. If all is good, don't mess with it, unless you're thinking about more ooomph. You can re-install the jugs with the pistons in their original position this way.

If you do end up re-doing the top end, I would recommend a slight increase in compression ratio. Something around 9.5:1 is good, IMO. My stock EVO is like 8-8.5:1. At 9.5:1, you can run 91/93 octane, and it will be happy. And you will squeeze a bit more HP out of the stock displacement. Consider having the heads 'street ported'. Nothing radical, just clean them up a bit. At the very least, get a good three angle valve job. Couple this with a decent cam (I run an Andrews EV27, with stock CR, but there are other good ones), a good air cleaner, free flowing mufflers/exhaust (I don't like straight pipes, JMO), and a Dyna or other ignition system. I run regular Champions, either from the HD dealer, or the local auto parts store. IIRC, the gap is 'around' .040. There's a big fudge factor.

This combo, using a tuned CV carb, will get you over (and possibly well over with the CR increase) 80/80 from a stock displacement EVO. With very little degradation of longevity. I'm running everything above, without the increased CR, and dyno around those numbers, depending on dyno/temperature, etc. There is a NOTICEABLE difference in ridability. Two up, loaded, headwind, passing slow semi's uphill. It just pulls like you would expect it to. My bone stock EVO was an anchor compared to the lightly modified one I now have.

It doesn't take much to make the 80" EVO run better than what The MoCo originally sold. Well worth the time/effort/money, IMO.

Oh, base gasket leaks: Install The Oil Fix by Hayden M6. You won't have any leaks. Been six years since it was installed on my 93 FLHS. Still bone dry.

Good Luck.

 

Use NGK Iridium, you won't regret it, its all I use these days, everything else is less....

 

hey Hacked.... were is a good place by us for motor work.... i live in westland...

 

^you got mail.

 

No brainer on a top end pull down, 9.5-1 pistons, EV 27 and at least a valve job as stock 80" are slugs, the only side effect is a erection lasting for 3 hours.

 

Where would you find the "Oil Fix by Hayden"?
Cooter

 

Um, an internet search, 1st hit

 

Don't even pull the tank. Unbolt the back and loosen the front, disconnect the fuel line and just lift the back up and prop it with a block of wood. Dont have to mess with the crossover that way.