650 squarenose questions

[surfjunkie]

just picked up a 93 squarenose with the stock 650 in it to be a donor hull while i do some much needed maintenance to my 03.

before i pull the 650 engine i'm trying to assess it's health. its pretty much of a dog compared to my 03. tops out at maybe 35 and isn't in a hurry to get there. ive never ridden a 650 before, does that sound about right.

i tested the compression with the engine warm, with the throttle wide open and got 135 psi on the rear cylinder and 140 on the front. is that a reasonable variation. this gauge has always read about 10 psi low compared to others, so it maybe 145 and 150.

any knowledge will be appreciated.

 

[Boris]

For a stock 650 that sounds about right.
You pull the throttle, stand back and wait as it slowly moves you forward.
150/150 is stock compression so it sounds healthy enough.

Any pipe will make a huge difference.

 

[surfjunkie]

thanks for the response boris.

i'm trying to make sure the hi and lo speed screws are set to factory specs, but my manual lists two carb possibilities for the sj650 engine: carb id 6r700 or 6r701-03. it gives different settings depending on which you have. i've looked them over and am not finding those numbers.

anyone know where they are or how to know which i have?


edit: the ski seemed to run a little fat and blubbery and the plugs looked pretty rich, just seated the mixture screws and the lo was out 3 1/8 turns and the hi was out 2 7/8. the manual calls for 1 1/4 for both the hi and lo +/- depending on which carb you have, so they were way off. that would cause it to run a little fat right?

 

[3wheelerdude]

I cant really help you with the screw setting, but I can assure you that my 650 is no dog. Its not a 701, but with a good piepe and impeller it pulls hard outta the hole. Top speed is not very high and probably affected by the high pitch impeller but who needs top speed anyway?

Get a pipe and junk the stock impeller and you should have plenty of power to have fun.

 

[Sdiddy]

650 is a dog

Scott just attach a lawn chair to it and it can double as a sun deck. As slow is it moves you should be able to make it work.