Hello I have a L1984 xlx1000. It has obviously been stroked and has aftermarket parts but my question is... The front cylinder left side has the 7 numbers and single letter (16581 72b) which is a oem cylinder used from 72-85 I'm pretty sure , but (shown in attached picture) the rear cylinder, same area, left side has only 6 numbers and no letter (090983). I tried searching it a few different ways and nothing comes up cany find anything.... Is this aftermarket, or number coding that is for measurements, or something? Can anyone tell me what these numbers are and what they mean please? Thank you

 

Also noticed both rockerboxes are aiming the same way, so it must be two rear jugs? It was completely modded before it was given to me with a blown hole in the bottom right case and the engine does have a lot of modifications, machined cuttings in cases rear cylinder hole for piston rod clearance(guessing they made it into a stroker?), both pistons have cut spots (front pistons rear bottom has an angled cut, rear pistons front has an angled cut) that are obviously precise angles amd amounts made with a mill or cnc also guessing because it was turned into a stroker and were made for clearance? Inside of Cylinders are both fresh looking with new cross hatching, and pistons look like they only had a few miles on them. Not sure if cylinders are just honed or if they were bored, and not sure if pistons are forged or cast or oversized or whatever, and not sure of anything about the piston rods (must be longer than stock if they had to remove some material in the case and on pistons for clearance?) Pretty sure valves and valve seats are oversized diameter. the trans was blown up so im not sure will have to look at one of the old gears to see what they are but im pretty sure they were aftermarket. is this something people do? Like is it a drag bike thing? Guess I'm going to have a better look at the valves to see if they were machined to switch which valve is for intake and for exhaust because otherwise wouldnt i have to switch the cam timing for front cylinder intake and exhaust to be opposite? Or maybe I don't have them on how they had them installed and they had one cylinder mounted opposite way on case for some reason like possibly running two separate carburators? I seen a post where they showed a ironhead with two of the same side cylinders and one exhaust was on the left side idk why they would do that besides to run single carbs. So if anyone can help me figure all this out and know the reason why my engine is set up like that or if i should have one cylinder om backwards like the one i seen on another forum, let me know, amd tell me what I should do or need to do please. I haven't removed rockerboxes but I'll take pictures of valves through the inside of the cylinders, and Ill try to take pictures of the cuts in engine case(only left side case now has machined cut since i replaced right side and just dremeled out the area more provably a bad idea bit i dont see a problem with it) and the machined cuts made on the pistons. Don't think I seen any markings or anything on the rods. I'll try to take some random measurements with my dial calipers to but I don't know exactly which spot to which spots I'm supposed to measure on all the parts, so they might be all wrong measurements, and my calipers are cheap so they probably arent exactly accurate, but in the mean time id still like to hear peoples advice and opinions. Thanks
Here's a picture of the one I seen on another post.

 

Sorry the shape of the rocker boxes is supposed to be the same shape aiming the same way...Oil line ports are where they are supposed to be also. Does that mean that it's using a front cylinder head? Is that ok to run a rear cylinder as a front cylinder with a front cylinder head on it? Maybe it's modified?

 

I'm reading this and at the end, all I can say is WTF!!!! I'm trying to understand this. You say a late 1984 XLX 1000. Now the 2nd post shows a photo of a blue and white rigid frame EVO Sportster, as you've seen on another post. Does that OTHER bike have anything to do with a L84 XLX? From the 2nd post description of what yer doing, I would suggest doing research on who modified it, who owned it and who did the machine work on it. Without that information, ya just bought someone's Project Bike Gone Bad.

 

Please post pictures of your bike and only your bike, to get better response, good luck.

 

@TexasScooterTrash second picture is to show someone that used to front cylinders like I was talking about because for some reason i think thos boke has two rear cylinders on it amd idk why... I don't know the last owner was given it as a gift, checked not stolen but hasn't been registered in almost seven years, guess I'll have to try and find them if I can.... Do you know anything about the numbers in the first picture for a jug? Can't find anything on it.

 

Well, thank you for clearing that up. All that rambling and that godawful EVO was for nothing. Last 2 digits are 1st year of the part. Not enough digits on that cylinder has confused you? It's an AFTERMARKET REPRODUCTION CYLINDER, not OEM HD.

 

Haha yeah sorry I was thinking of all the possibilities why a rear would be on a front then came across threads of people running two front or rear cylinders etc....Is there anyway I can find out the aftermarket cylinder producer? I tried googling the numbers and I might just be stupid but I can't find a thing about it.