I got an 04 700 twin carborated model at the garage thats my friends. It has a bad knock in it. At idle there is a bit of tapping off and on but i wouldnt think it was a problem, but when you rev it up it sounds like something is gonna shoot threw the case on the front right water pump stator area. Oil was dirty but not terrible, i put fresh stuff in it no change. It doesnt over heat at all, no excessive crankcase pressure or smoke. There wasnt any signs of metal when i dropped the oil either. It seems as it gets worse once its hot. Is there any common problems like this, water pump or oil pump problems?? 2 weeks ago it ran for 6 hours of riding with no problems, this weekend we went 3/4s of a mile it started nocking so i towwed it right back. Any help would be appreciated.
Rob

 

How many miles are on it? if it gets worse when warm, could be slop in the rods, or the crank bearing starting to go, hard to tell without actually hearing it. You were smart to tow it back when you heard the noise on the trail.
Maybe see if you can PM Old Polaris Tech (OPT), he is a retired Polaris mechanic, and should be able to help you out.

 

Sounds like if you run it any longer you will have a souvenir 700 rod and piston like I have hanging on my tool box!! If you haven't had the updated ignition(if early model) or even if you have the Kokusan ignition,seems like this would sometimes happen(could be just coincidence or a bad run of bearings,or timing altered enough because of the Ducati systems to cause damage?) . Sounds like above mentioned rod slap.You can pull the right side covers and check out all the gears,pump,etc,but from you're description sounds like a lower rod bearing is going out. Keep us updated. OPT

 

Seems like ill be pulling the engine then. Where can i find a good source for a service book for this model?

 

Best manual for the 700 is the Polaris service manual. Will explain better than Clymer or Haynes and the pics are usually better. Try Partshark.com for down loading one. OPT

 

Well i split the bottom case off last night, and found a bad rod. I have been looking a little online and it seems you can only buy the rods and bearings as one in the crank kit. Is that the only way to replace a rod and rod bearing?

 

Seems like Polaris has the market cornered on this one! Unless you can match the rod and bearing up else where,Polaris wants you to buy the whole crankshaft assembly! Cheapest I've found is $750 at Cycle Parts Warehouse, $662 at Cheap Cycle Parts,still not cheap by any means! If you find an alternate way,post it for the other members! OPT

 

Im gonna visit my machinist/ engine builder that does my work and see if hell tackle it.
Im thinking bore the rod out and clean the crank up and fit a needle roller bearing in there like on wrist pins.