i am going to make my rappy a 686 after the valve bent and wasted my piston. I am going to order
Stage 2 HotCam (or should i get another?)
HotCam Valve Spring Kit (or is there a better one?)
686cc JE 102mm 12:1 pistion (or should i do something different)
and WHO would you have bore it to a 686 and whats the cost on that?

is there anything else i should do or shouldn't do? one of my valves broke so should i replace them all with SS ones? or just buy another stock one?

ANY AND ALL suggestions are VERY much welcome, trying to keep this in the $600.00 range

 

http://www.trinityracingproducts.com/bigborhoncyl.html
is that all i would need done to take it to the 102mm? (686)

 

Give Craycraft a call on the piston and cam; any good reliable machine shop should be able to do your cylinder bore. Take them the piston that has the specs with it when you bore it so if they are not sure of anything as far as what size piston you will be running they will know for sure. If keeping it in the 600.00 dollar range is a big concern get another stock valve to replace the bad one and get a good valve job but also check the condition of the other stock valves. Check your crank while you are there just to be safe. If you can while you are there go ahead and get a good port job and match the intakes up to the head. With these changes the bike should run very good! If you are doing the labor yourself this is close to your 600.00 dollar range but maybe just a little more. Piston 150.00 to 200.00 (just depends) Cam around 140.00 Valve 40.00 Bore 50.00 Gaskets 60.00 to 75.00 Spring Kit 170.00 Three angle Valve job 75.00 (IF YOU CAN - PORT JOB AND MATCH INTAKES 300.00) Later and Good Luck Slim

 

I agree 100% with what Slim said! Except I paid more than triple what he says for a valve job, but its different than a 3 angle. Call around for prices before you go anywhere for machine work.
Good choice of parts, makes sure you get a HP gasket for it. If you call Craycraft he will have them.

 

SLIM660 you would go with crafty over other builders? and will the extra 300 bucks on the port job really make that much of a difference? and would you stick with craftys cam other then the hotcam, his is more? and would i gain anything from putting ALL after market valves in, and would i just have to lap them all or would other work be required?

 

I'm not Slim but I'll throw in my $.02 anyway.
Yes I would go with Craycraft over all others. You WILL NOT find better customer service ANYWHERE!
The price for a port job would be well worth it if you can do it.
Craycraft primarially uses Hot Cams, I think. I am sure he could get you another if you wanted it.
Stainless valves are lighter than the stock ones, I would assume stronger as well but I'm not sure. If you can get SS valves I would. If it is valves or a port job get the port work. There can be more done to the valves than just lapping them. A good valve job helps to increase flow.

 

Ugintel, The reason I would go with Craycraft on the piston is that he offers more than just the piston. He can give you some mods to the piston that not many offer and his all around service is very good. In my opinion from what I have seen the valves are not making a lot of difference in the performance(SOME WILL DISSAGREE) but thats from what I have seen. If you decide to go with the same size aftermarket valves the valve job will take care of the valves fitment. The StageII cam is a good choice in cams and it will perform well. There are other cams available that will perform better at the strip but it will take a little more work to get them to perform like they can. If you want to still trail ride the bike and be good at the drags the stageII is a good cam. The funny thing is about going to a bigger cam profile beyond the StageII is thay have a higher lift and duration and they like more air and fuel to be fed into the motor to perform at there full potential which requires a little more work. The bigger cams will mainly give better top end which is why I chose the Web 685. Concerning the port job It will make a good difference ecpecially along with the other upgrades. If you go with the setup you listed I dont think you will be dissappointed. It will be a major difference in performance over stock. Slim

 

I also agree I would just send it to craycraft and let them do the work on the cyl. and head. Their port job also includes a nice valve job and matching your intake boots to the ports. If they bore it they also set your ring gap. And their prices and especially their service are excellent.
I would also strongly reccomend that you have your carbs modded if you go with that set up.

 

sixsixT when you say modded carbs, what are you talking about and whats the price?

 

I don't meen to sound like a sales rep for craycraft but..... he does mods to the stock carbs that will allow enough fuel to flow into them for modded engines and the parts he uses also eliminates the problem with maintaining the proper float level, especially when using race fuel which you'll need for that engine. Ask Bob about it he can tell you more than I can.