650 Engine Question

[Grantster]

I fell while turning fairly sharp on my 650sx, and got water in the engine, then proceeded to grenade the engine. Is there any reason why the water would've gotten in it?

 

[Pro-pulsion]

Yup, probably the engine drain plug is getting wonky and let water in. See that choke style plunger on the exhaust manifold? That is basically a choke cable to open a flap valve with two rubber cone shaped plugs on the bottom of the cases. The idea was actually rather good to have a quick drain for a water filled engine but the method used was not so good. The easy fix for that is while the engine is out, take that setup off totally. Where the rubber plugs seat into the holes, just put a coating of JB Weld on the threads on a 1/2-13 x 1/2" if I remember correctly...stainless bolt, hex is better than socket head here, don't tap the threads, just force thread the bolts in. They will cut their own threads just nicely and won't send chips into the crank case. The coating of JB will seal the bolts permanently. I did this to my old 6fiddy and never had an issue but certainly improved the reliability. I believe all of this info has been put into my old build thread. Have a looky, you might find something of use there

http://www.x-h2o.com/index.php?threads/completed-650sx-build-from-50hp-to-60.54481/

 

[Vumad]

650 hulls and waterboxes are terrible.