My friends 2004 1200 Sportster cracked a piston the other day. The bike only had 17,000 miles. We pulled the motor apart and both heads are marred badly. One piston is completely destroyed. He said he was at a stop sign and the bike just died.

My first question is could I just use a 883 to 1200 conversion kit to replace the sleeve and piston. Where is the best/cheapest place to get that and to get 2 heads?

My second question is what do we do about all the pieces of piston ring, piston, and head in the lower part of the motor?

 

Ouch. What do you think causes something like that to happen?

 

Running to hot and Detonation.............

Cheap is not the way to go if he plans on keeping the bike. Quality is the right way to handle these types of matters.

 

www.nrhsperformance.com this is where I would start. 700 for a 1250 kit. And they make top quality parts.

 

Unfortunately, this repair is going to require a lot more than a top-end kit. The motor is going to have to come out of the bike and the cases split open in order to clean the debris out of the bottom-end and replace any damaged parts.

The OP may be better off looking around for a wrecked/totaled bike with a good donor motor.

 

You could get the jugs bored & heads milled for new pistons. Gotta tear everything out & flush the block. Might be cheaper to go w/rebuilt motor - saw a few on eBay & CraigsList. Price both options & do pro/con...good luck!

 

If the motor is in that bad of shape from Detionation then your crank and lower bearings are proably all banged up. BUT if the bike was detionating that badly the bike should of barly ran. Only other time ive seen that is from someone runing Nitrous and it goes lean on the bottle. Time for a whole new crate motor

 

That sounds pretty catastrophic for a simple "stop sign" death. What is the background on this bike? I'd also have those connecting rods and all bearings checked or replaced. You're going to have to split the cases to make sure all the oil galleries are free of metal debris.

Bummer.

John

 

My friend never rode hard and always took care of the bike.. I was gonna tell him to call Harley and complain, but I doubt theyd do anything.

Gonna look around for a new motor.

By split the case do you mean seperate the trans from the motor?

 

and don't forget the oil pump....it may have failed...