srx 787

J

jsand117

New member
Joined
Oct 17, 2007
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19
Age
61
Location
scranton pennsylvania
I have a friend that got out of snowmobiling and gave me a top end for a srx 787 big bore. I have the cylinders, pistons and heads and powervalve. I dont know much about this motor combination, i run 835 bender but dont know who made the 787. the bore on the box says 72.90 mm arts pistons, they apear to be cast pistons. one cylinder needs to be repaired, who repairs these cylinders? do these motors make good power? reliability?? info would be appreciated.
 

its a 780 , all 780 are 73mm(72.9), the only other one was a 74 mm which hauck made. The cast piston engine was made by maxx perf who is no longer in buss. They used a cat 580 cast piston and a spacer under the cylinders. The thing with a 780 its not so much the pistons but the cylinders, they get thin from such a large overbore and the rear skirts are prone to damage if the motor suffers any detonation at all. The wiseco piston used in most is very hard and requires more skirt to wall then the cast piston does but both will still break the rear skirts if detonated. I have welded up the rear skirts to brace them and then turn them on a lathe to produce a thicker skirt support tab. 780 is a great engine as long as you keep good fuel in it and safe jetting, its the guys who go rippin right off the trailer without warming up engine first who have the cold seize problems and broken skirts. Its not for a person without self control.
 
jsand117 said:
I have a friend that got out of snowmobiling and gave me a top end for a srx 787 big bore. I have the cylinders, pistons and heads and powervalve. I dont know much about this motor combination, i run 835 bender but dont know who made the 787. the bore on the box says 72.90 mm arts pistons, they apear to be cast pistons. one cylinder needs to be repaired, who repairs these cylinders? do these motors make good power? reliability?? info would be appreciated.
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The reliability is just fine, provided you let them warm up thoroughly, and keep good fuel in them. Power depends on porting, and the rest of the combo, of course. My 780 made 181hp at dynotech, with moderate porting, Bender 835 pipes, ported cases, and trail safe jetting.
 
If ya wanna see another nice one, go on the 4-stroke side and check out Iceman57. All I can say is Damn! Sorry bout the hijack.
 
Haha. I am willing to drive to meet the purchaser, at the purchaser's expense. I would not ship it. I want to meet it's new owner, to go through the sled, and explain everything that was done to it.
 
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