Will 81 top end mate with 82 bottom end

I have a good 82 bottom end wanted to make sure I can use my 81 top end to make a good motor

 

Welcome, just a heads up. If you put the model/year/spec etc of your bike/bikes into your signature line it makes it easier for members to offer model specific help (and you don't have to keep repeating yourself when someone asks then either )

I'd say that you probably would be fine, but it does depend on what model as there may be some that don't match. (and obviously an 1100 top end wouldn't do much good for a 550 bottom end, I know you're not asking that but without the details it is a little ambiguous)

Again welcome & as I say I'm sure you'll be fine but we'll know more when a model expert chimes in

 

One main issue is YICS - VS - non YICS
post the numbers-letters stamped in the engine case over the clutch.

 

Thanks guys I will have to get numbers both bikes are xj maxim 66"


650

 

Oh yeah that could be an issue, the YICS system came in between '81-'82 so would be the main difference.

If you post a picture of the top of both sets of barrels (the head gasket mating surfaces) we'll be able to tell.

I'm sure somebody will correct me if I'm wrong, but as long as both head & barrels are either YICS or non-YICS the rest should be fine to match up...

 

The only real concern about swapping YICS with non-YICS is that you will need to use the complete top end (cylinders, head, cam cover). The correct carb to head intake boots will also need to be used.

That said.
YICS Models
All 750's
82-83 650 Maxim
81-93 550's
85-86 700's

non-YICS Models
80-81 650 Maxim, and 82 650RJ Seca were non-YICS

Ghost

 

Except for the 1982 CANADIAN XJ650RJC Seca models, which were YICS-equipped.

Yamaha has lots of little quirks in their models which make it really hard to generalize at times...........


P.S.: the 1985-86 XJ700-X and XJ750-X (water cooled) models were non-YICS, too, as the 3 intake valves per cylinder basically achieved much the same effect as the YICS system did........