Identifying an 81 PE175X or 84 PE175E cylinder vs an 82-83?

[Chuck78]

Is there any easy way to identify an 81 or 84 PE175 X / PE175E cylinder to distinguish it from an 82-83?

Is the cylinder porting on an 81 the same as an 80 model? 

I'm looking to pick up a second as a spare, and bore it 2mm oversized and have it Nikasil plated, and looking to get either the 1981 or the 1984 porting specs.  I know I can just pay to have someone professionally port it, or I can search around until I come up with some tips on minor DIY porting tips to perform myself, but if I can just pick up an 81 or 84 cylinder to begin with, that'd be nice.  This is for an 83 PE175 project of mine. I need to get this thing going so the wife has something to ride. It's plenty sedate as is for her to ride with lower compression and the more mild 82-83 porting, but I aspire for more eventually. 

I don't believe the Suzuki part numbers are cast into them, but that would be very nice if they were! 

Any tips are incredibly welcomed.  Thank you in advance. 

-Chuck

[Chuck78]

'81 PE175X cylinder: 11210-40500 (superseded by '84 part#)

'81 PE175X cylinder: 11210-40501 (superseded by '84 part#)

'84 PE175E cylinder: 11210-40503

EDIT - Hmmm.... '82-'84 on the PartsOutlaw.com  parts fiches are showing all the same part numbers... I had definitely read an article which stated that the '84 porting was changed again from the 82-83, and that it had a much better mid range and top end, which I definitely will confirm from my experiences riding my buddy David's '84 PE175 versus this 83. In defense of the '83, it does likely need at least new piston rings.

[ESR80PE]

I know you can tell the difference between RM and PE barrels by a R or P cast into them. I cant help with RS or PE 175 ID across the years though.

The way you can compare 80 to 81 175 is check the part numbers. But also check the type of fin rubbers. The porting might be the same but just the fins could be different. This is the case with the 250. 81 has verticle slots in the fins for block rubbers and 80 does not as it uses rubber discs.

Best way to too compare 175 barrels is to actually look at the original 175 parts books and ignore sites like Partsoutlaw as they are not an accurate representation of what each model had when new and they often just list the most newest version of the part.

[Chuck78]

Actually what I found was the opposite, the parts websites show former superseded part numbers as well as most current replacement, but the cross reference program that someone showed me a reference to, shows only 1984 PE175 cylinder part number and says that is what fit all models 80-84.

I suppose you would have to have a proper Suzuki parts book from the last year that the model was made or later, but that still may only show the current fitment? Perhaps you might need one from every single year to catch all the changes?
I've never been fortunate enough to have one of these Suzuki OEM parts books, so I'm just speculating!

[twinshock]

The cylinder porting on the '81 is different from the '80 model. The exhaust port roof was lowered by 1mm. There may be differences in the intakes as well, but have not checked yet. Suzuki apparently modified the '81 cylinder to extract a little more bottom and mid range performance.