660 rebuild suggestions

[hypersnyper6947]

I am helping a friend with his 660 rebuild, we already have the stage 1 hotcam to go in, im thinking 11:1 compression piston, we are loosing the air box lid and putting in a fmf powerbomb header and powercore slip on, so full exhaust. Of coarse we are going to rejet the carbs, but other than that what other things should we do or replace. Also should we bore it a bit if so to what? Oh yea we will be replacing the timing chain, is there a HD one available for the raptor?

Thanks

i just rebuilt mine and i just went another .20 over.... so im a full mil over bore which put me a 672cc... Id just go minimal so incase one day he really greanades it ull have room to rebore the cylinder....:D

[raptor686boi]

are you going to put the valve spring kit for the stage two hot cam in. If not put it in. should port & polish it. ;)

[hypersnyper6947]

K we got it all taken apart for my previous thread readers. Our plan is to bore it to a 100.5mm and do a wiesco 11:1 compression piston. We are doing a stage 1 cam so we are not changing any valves or springs. I think having it bored to that should get rid of any imperfections and give it a good hone.

you can get away with using a stage 2 cam. It only has like .002 more lift than the factory, and i know that the duration isnt that much either.... Fisher cycles in astabula Ohio actually reccomends usin the stock valve springs. I guess that the HD spring tend to become brittle and break.... thats what he recommended to me....

[hypersnyper6947]

ok i got the 101mm 11:1 wiesco piston ordered i just cant seem to find a 101mm gasket anywhere. Will the stock 100mm gasket set work? or does it need to be 101mm specific, i find them for 102mm all day but no 101mm

101 will work fine....

[hypersnyper6947]

So we got it all rebuilt and put back together and now for some reason it wont start. It sounds to me like it has no compression. Out it def should considering a brand new rebuild. Any suggestions?

[tater_kamik]

so... you got an oversize piston and you went and got the cylinder bored. what makes you believe you are lacking compression? you will have to put in a lot more detail if anyone will be able to help ya

[hypersnyper6947]

Yea... We got it figured out, the valve lash was way off for the new cam and it was not allowing the valves to close, result, no compression. It runs like a champ now, and dam its fast!! Now we are having trouble with the starting relay. The battery is brand new and charged and it just clicks when you hit the starter. If you take a screwdriver and cross the 2 bolts it will start. WTF?? We are thinking the wiring is effed on the relay but any input would be great.