1993 xp what engine do i have?

[cruisertom]

Ok here is my problem, I bought this thing not running and got it running last summer only to find the impeller splines were stripped. As I am looking for a new one I find that the flywheel case has a tag that says 587 on it. Today when I picked up a new impeller from a guy he had a 587 and a 650 sitting next to each other. (both were white engines) I told him my head cover had the lettering on it and he said that means I have a 650. But I have the smaller engine balancer on the driveshaft end, but have the dual carbs. He said that the front covers (flywheel) are interchangeable so maybe someone changed it out. So my real question is how can I be sure of what engine I have so I can install the correct impeller? He was kind enough to give me both and mail back the other when I figure it out. I was unable to find any pics on the internet to confirm what I have. Thanks for any insight.

 

[Dr Honda]

pop the head off, and measure the bore.

 

[mtrainer]

Use the formula PieR^2 to find the area of the piston. So 3.14 times the raduis (half as wide as the piston) squared. Then multiply the area of the piston by the stroke (length the piston goes down) multiplied by 2 (number of cylinders). That is your engine displacement in cubic inches.

 

[LouDoo]

There should be a sticker on the mag. cover that reads Type: Here's what the one on my 96GTI looks like.

Lou

 

[cruisertom]

I was hoping there was another way like casting stamp or something on the block. If I pull the head cover then won't I have to replace the gasket?

 

[rotaxrule1]

Should be fine, I think it has o rings and should be reusable. (correct me if I am wrong guys)

 

[cruisertom]

Ok measured and my figures came out to 641.77cc. So I guess I have the 650 with 587 front cover and PTO balancer? My bore was approx. 3 3/32 and stroke 2 19/32 which converts to 39.18 Cubic inches. Why would someone do this? Was it just the parts because in the manual it says that it is important to have the correct balancer and ring gear as they are balanced to the shaft.