I have heard some great news form Craycraft for all of the forum members with head gasket problems on your raptor.

The kit contains studs, nuts and washers for the cylinder and head. The studs are made from 4340 with rolled threads.

With more motors being built with higher compressions and NOS applications this kit will be what will help maintain your top end integrity and help prevent premature head gasket failures. The torque for the cylinder studs is 60 foot lbs from the factory spec of 30 foot lbs. The head studs is 54 foot lbs from the factory spec of 27 foot lbs. For more details call me at 817-441-5893.

 

If i was building a 727 or a high comp 686 i would get them in a heart beat. The 2 headbolts under the cover always loosen up. I have seen many head gasket failures when hitting the nos button.

 

How long will a HP Cometic last in a 12:1 686? I'll get the studs when I have to take it apart but hopefully not to soon! [img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Is a 20 shot on a stock internal engine ok without the stud kit? I am trying to get as much reliable hp out of my bike with just bolt ons while leaving the internals stock, for now at least. I think about the only things I have left is a sixsixt K&N adapter. What other external mods could I do for a reasonable price? Thanks

Street

 

It may be ok wallstreet, you will know if it's blown if your coolant overflow tank suddenly fills up

 

this is the best thing ever made for the rappy i blew my head gasket this past weekend because i can not get the head tight enough i just got of the phone with bob and i order mine im tired of blowing head gasket it sucks i cant believe all of the people on this site that have modded raptors and dont have this on order thats crazy heck its worth the money for the piece of mind knowing that your motor is done right yamaha did not design the raptor motor to run with the comp that we all are running at and no matter who built your motor using the stock head bolts your going to blow the gasket sooner or later ( my luck it would be on a sand dune trip) just my 2 cents

 

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I agree totally! After thinking about it a minute when you talked to Bob did you ask if you can change the studs out without taking the engine out of the bike? I'm not so sure the head will miss the frame while sliding it over the studs. Mine are gonna be on order soon.[img]i/expressions/face-icon-small-smile.gif[/img]

 

yes, you can take the entire head off and put it on in the frame.

edit - Nevermind, I guess you are right that is a good question, I didnt know they were studs.