How to tell whether its a 657 or 657X?

[aberdeino]

Hi, have a 1994 speedster with a seized engine been trying for ages to find out whether its a 657 or a 657x. How do you tell???

Thanks, Al

 

[seadoosnipe]

657x...

Your model engine is the 657X series. .............:cheers:

 

[aberdeino]

...have also been offered an engine out of an XP? the seller doesn't know age or whether its a 657 or 657x so really need to know how you tell them apart.....

 

[timmyboy76]

besides the "plate" on the magneto housing, if the "XP" is from a 94', then yes, has the 657X motor

 

[Dennis]

657x?

The intake ports on the side of the cases on a 657 non X motor are oval. The ports on a 657X are round.
DAWG

 

[bdagold]

657X to be or not to be?

I am a little confused as I have just pulled my engine out of a 95 Sportster and the plate on the magneto says 657X and the ports on the rotary valve and the carb manifold are actually oval. The manifold on the 657X do not have the studs on them, but the engines below that cc have the studs on the manifold for the smaller 38MM carbs. I hope that i am right, but this the configuration that I have on my 657X as i have just finished a complete top end rebuild. I hope that this helps and if i am wrong please correct me..

 

[Dennis]

657x ?

I've got it backwards.
The 657X motor has a oval port and the 657 has a round port. Sorry about any confussion this may have caused.
DAWG

 

[bdagold]

Dennis not a problem. This is what makes this forum the best. We all try to help out in any way we can. :hurray: