I just recently had motor work done on my bike at one of the local H-D dealerships. Ever since I got it back my fuel mileage dropped to less than 30 mpg. Here's the story!

Ever since I bought this bike it has been a learning experience. I noticed that it had Screaming Eagle heads on it when I bought it, but didn't know the extent of the modifications to the engine. I've picked up info on the bike as I've had work done on it, and did a lot of research and speculation on what was in the engine. I knew it had SE 258 cams after the cam chain tensioners were replaced. I checked the compression myself and using BigBoyz compression calculator I assumed that I had the SE 10.25:1 pistons. I WAS WRONG!

After this recent work was done, I wanted to see what compression my bike was making with the new TW55 cams in it. They were done just before the bike went to the dealer. I was shocked to see the compression guage go to 220 psi. Now I was really concerned and could not figure how my engine could make that kind of compression with what I "knew" to be in there. I went to the dealer and talked with the mechanic about my build. He said that I had the high dome with matching heads SE setup. My compression was what it is supposed to be with that kind of setup. Now I know why it had the SE 258's in it.

I don't need this kind of headache! I sure wish I had bought a bike with a bone stock engine. I guess that I'll have to update my signature after I get it dialed in this coming week. I'm wondering what kind of numbers it will make.

My word of advice to anyone buying a used bike is this: Buy from an individual or a dealership who can tell you exactly what has been done to the engine or bike, or just walk away. I'm really discouraged now because I wish I could have changed the piston and heads to a milder beast. I just can't afford it right now. Maybe down the road awhile I'll tame this beast!

Anybody else with this kind of build that offer advice on how to live with this HIGH compression situation will be greatly appreciated!

 

Just curious...what exactly is causing you a headache? I'm running a pretty compression engine with no problems at all. Getting about 38 mpg on average.

 

My h.q. build has about 222-223 compresion 10.5:1 113" and I get low 40's mpg. higher compresion actualy helps mpg if it is bad look at the tune!

 

Yea, sucks real bad to have TOO much power huh. Maybe a Honda Rebel next?

 

Sounds like you could benefit by a precise dyno tune.

 

look at the tune... maybe go to a thunder max w/ auto tune.

 

Mostly the added stress on engine components. I never wanted the engine to be this extreme, and I never figured that it was this modified. That's why I remarked about knowing what mods were done to the bike before buying. I bought mine from a dealer who sells used bikes of all kinds and buys a lot from auctions, hence he couldn't tell me anything much about the bike.
I don't want or need bragging rights about my bike. I just want a rock solid dependable bike that I can enjoy long trips with momma or friends.

 

Your problem is a lousy tune, not 220 psi CCP.

 

i have a stock 88 i cantrade for your 95

 

I have a stock 96 in my 97 I'll trade with you