Motor Identification...

Hello,

I recently purchased a 1982 Maxim for $100 from a guy who had left it sitting in his yard for 13 years...he said it is a 650 but some things lead me to believe otherwise...

I am curious to know how I can identify the motor as a 650 or not. The VIN tag on the neck of the bike is all but gone so I don't have a number to give but I do have an engine code stamped on the block...


5/8 - 008681

Other than that, I have no identifiabe marks on the bike...

If anyone has any suggestions, please send 'em!!!!


Thanks,

Jon

 

on the right side of the engine, should be another set of identifying marks.

xxx-xxxxxx

Or you could pull the top off one of the carbs and check the sizes of the air jets, hopefully they are still stock.

 

Yeah...in retrospect, I believe the "5/8..." is actually "5N8"

The carb jets were 120 and 40...I ampretty sure they are stock...this is what leads me to believe it might be a 750 not a 650....just want to make sure before I start ordering the expensive stuff...


Thanks,

Jon

Okay, so I just reread you post. The air jets were so badly mangled and stained that I couldn't read them...they had not been touched but they looked like they had sat in a vat of coffee grinds since 1984...

Thanks for the input!!!

 

ok...

check the size of the needles to see what they are.

 

The 5N8 code identifies it as an XJ650 Maxim. If the 5N8-xxxxxx code is also on the engine case, then it too is a 650 engine.

The #120 and #40 fuel jets are indicative of an XJ750 carb set....someone may have swapped a set of carbs off a 750 onto that bike, or just changed the jets.

XJ650 needles are Y-10 size, while XJ750 needles are stamped with the Y-13 size.

An otherwise stock 650 engine will run very rich with a set of 750 carbs on them, due to the jetting differences.

 

Chacal, thanks for the heads up!

I will be ordering a whole boatload of stuff from you very shortly.

Regards,

Jon