Hello, I need a wiring diagram for a big twin evo 86' . It is the first evo engine that was maked.I need it for my sportster . grtz, Andy Belgium

Duplicate question already answered

You didn't state if it's a Sportster or a Big Twin, so I'm gonna go with a Big Twin.

http://i662.photobucket.com/albums/uu346/chopsgarage/97softailoil.jpg

If your bike is equipped with the Evolution engine there is no adjustment on the rocker arms, the engine is equipped with hydraulic tappets. The pushrods on the Big Twin Evo engine are color coded and go in a particular position. They are different lengths. The blue color coded pushrod is the rear intake pushrod, the purple color coded pushrod is the exhaust pushrod. The pushrods for the Evo Sportster are all the same and there is no adjustment on those eiher provided they are stock.

Now, if you are working on something other than an Evolution engine or you have aftermarket pushrods, please repost and I'll tell you what I know about the valve adjustment for your engine.

Steve

Well, it depends on the year and model of the Harley. On the earlier Harley, both the Big Twins and the Sportsters, the generator was located externally on the lower front of the engine. In 1970, the Big Twins went to an alternator. It was and still is located in the forward end of the primary cover on the engines sprocket shaft. The Sportster didn't got to the alternator until late 1984. From that year to 1990, the alternator was behind the outer clutch basket at the rear of the primary. In 1991 to present, the alternator is located in the same place as it is on the Big Twin models, in the forward end of the primary case. I hope this helps.

Good Luck
Steve

Depends on what the problem is as to how much it will cost to fix it.
There are any number of things that could cause this problem. Since I'm not there to hear the noise, I'll just tell you what they are.

You could have a bad roller on a tappet. These seem to be a weak point on Harley Big Twins. However, the Twin Cam engine was designed to help minimize this problem by partially correcting the problem with poor valve train geometry that the Big Twins always suffered from. Look at the pushrod tubes on an Evo engine and Sportster engine. The Sportster has perfect valve train geometry where the Evo is all messed up. But, still the roller tappets on even the Twin Cams give problems. When this happens, they get an excessive amount of valve lash and the result is a very loud tapping in the head of the effected cylinder. Usually this takes out the cam/cams as well.

You could have lost a piston pin. This is highly unusual since Harley went to the standard piston pin locks instead of the spiral lock of years ago. Still it could have happened.

There are also a few other things that could have happened. A valve spring could have broken, or a valve keeper may have jumped out. It's difficult to tell without actually going into the engine.

Whatever it is, I hope it's not too bad.

Good luck
Steve

The oil is "gooey". Hmm. Cold 20W50 oil is gooey. There is nothing else in the engine to change the consistancy of the oil. Now, your oil tank is accessible without any tools. Possiblility someone could have put something in your oil. A good sniff of the oil should tell the story on that. If it smells like sugar or syrup, that's a good clue.

Now, If the bike wre a big twin, I'd guess you lost a roller on a tappet. Big Twins are notorious for this but the header says your bike is Sporty. I've never seen a Sporty lose a roller tappet. The Sportster has a much better valve train geometry than a Big Twin.

Have you checked for a blown head gasket? Evo Sportsters are known to be more vulnerable to that than the big twins. The easy way to find that is wait until it gets dark, start the engine, and rev it up a few times. Watch for a sharp flame to pop out betweent he head and the cylinder. It's easily seen in the dark.

Other than that, anything I could tell you would be a guess at best. Take a long screwdriver and put on bone in your head just in front of your ear. With the engine running, touch the engine in various places and try to determine where the noise is coming from. Sometimes this isn't easy as the noise will have a tendency to "travel through the engine". Otherwise the only thing you can do is a compression test or a leakdown test.

Good Luck
Steve

big twin would be the bigger HD motor, eg, 1340cc, motor with seperate gearbox.

You should be able to get what you need from most any motorcycle magazine that pictures a 90's model bike. Harley Davidson introduced the Evolution (EVO for short) in 1984 in most models of their Big Twin bikes. They used this engine until 1999 when they introduced the Twin Cam engine to most models. For the most part, all Evo engines looked alike. They had two versions, the stardard engine that was aluminum colored all over and the "black & chrome" engine that was painted black with the edges of the fines polished and chrome covers on the engine.

The Evolution Sportster engine was introduced in 1986 and is still in production today. They also had the standard engine and the "black & chrome" engine. These engines come in two sizes but are identical on the outside. The standard engine was 883 cc. displacement and the "black & chrome" engine was a 1200 cc version. Hope this helps.

join www.chopperweb.net/ ,,, its free ,,,, they have a searchable database of all the wiring diagrams you'll need plus the members help when u run into problems

You have a basic EVO designed engine with a CV carb.I dont think they have a TC Sportster yet.