883 to 1200 Problems

foggdog · #1 10-30-2009, 07:02 AM

After months of pure pleasure my '86 / 883 is re-assembled. Problem is, up-ward travel of front piston binds. Afraid to light it off, are there static measurements that can be done to make sure I won't blow the engine? How do you measure deck height for instance. I swapped out the 883 jugs & pistons for 1200 jugs & pistons only, nothing else changed & no modification to the lower end. Engine is on the work bench, any recommendations or direction?

My son began this project but lost an arm & leg in an accident on his Fat Boy. He's good at this, unfortunately the judge sent him to prison for felony DUI & Dad is trying to finish up. Like I said, it's enjoyable and a great way for an Old Man to spend his time, trouble is - No experience. Any assistance greatly appreciated, Thanks

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xFreebirdx · #2 10-30-2009, 07:28 AM

Here's some instructions to check the squish.

xFreebirdx · #3 10-30-2009, 07:30 AM

PS: You know that the intake and exhaust push rods are different lengths, right?

Did you use assembly lube on everything when you put it together?

By binding do you mean just real tight or is it actually hitting something?

SwtIron · #4 10-30-2009, 08:50 AM

sorry to hear aboutyour son. Regarding your message, I have solid black 883 cyiliddrs/pistons and heads top/bottom front and back. Also have the air cleaner kit. only 1,000 miles on all. I am seling these for $350.

drum412 · #5 10-30-2009, 09:54 AM

Did you pre-lube the cylinders. If not get some lubriplate assembly grease, and wipe a thin layer on the cylinder walls. Double check your piston ring gaps, and make sure there are no burs at the gap. Beyond that you can check your squish clearance and valve clearance using modeling clay on the top of the piston, then put your heads temporarily on and turn the engine manually, take the heads off and measure how thick the clay squished down for clearance measurments. If all checks out, I'd say go ahead and fire her up.

drum412 · #6 10-30-2009, 10:04 AM

And if in doubt, take your piston and cylinder off and show it to an indy mechanic and they'll let you know if your good to go. If it's binding because the piston is tilting during the upward movement, it's not too much to be concerned with, its common especially with new parts when your just moving it manually. Once it runs, it'll move straight, unless you have a mechanical issue like a warped cylinder wall.

prodrag1320 · #7 10-30-2009, 10:28 AM

if your running 883 heads with 1200 pistons,your running tons of compresion,either get dished pistons or releve the combustion chamber,if the piston is sticking on the top of the stroke,the cylinders are tapered,probley not bored & honed on proper equipment,fix it before you start it
kirby

kahaone · #8 10-30-2009, 11:54 AM

Quote:

Originally Posted by SwtIron

sorry to hear aboutyour son. Regarding your message, I have solid black 883 cyiliddrs/pistons and heads top/bottom front and back. Also have the air cleaner kit. only 1,000 miles on all. I am seling these for $350.

And just where in the original post did you determine that he was looking for down graded stuff to buy????

foggdog · #9 10-30-2009, 01:06 PM

Quote:

Originally Posted by xFreebirdx

PS: You know that the intake and exhaust push rods are different lengths, right?

Did you use assembly lube on everything when you put it together?

By binding do you mean just real tight or is it actually hitting something?

Didn't know about the push rod lengths & didn't use assembly lube, the binding is actually having the piston hit something. A guy I know installed thick cork gaskets, problem solved he said but I don't buy it.

I really appreciate all the input, I'll get busy checking things out. I may end up re-installing the original jugs & pistons. Thanks very much for the consideration you have all shown...

chester1957 · #10 10-30-2009, 01:11 PM

Prodrag is correct about the compession with 1200 parts and 883 heads.

Does the piston seem to stick or does it feel like it's hitting something. Helped a friend figure out why he couldn't roll his engine over to put the top end together, he had cylinders bored and Wiesco dished pistons with stock 883 heads. Turned out he put in 883 head gaskets vs 1200. Not saying something this silly has happened, but it is a possibility.