which cams should i buy? (xr 650L)

hey all,

I have a 1996 xr 650 L that i use as a commuting road bike. I have it converted over to street use only and intend to keep it as only a road bike. my buddy and i tore it down to the frame last night to clean it.....well, we ended up taking the head off the engine too to investigate and see some stuff....thats what alcohol and persuasion can do sometimes!

Anyways, i am wanting to see what kinds of aftermarket cams everyone is using because i am going to get a new one. Also, my buddy is going to port and polish my head for me.....he is doing something different though. He is going to make the inlet side smaller so that it creates more velocity for fuel entering the combustion chamber.....same with the exhaust ports too i think.....anyone ever heard of doing this? he says that is what the top fuel bikes do??? Any comments before i let him do this?

Well, if you could let me know some of the cams you guys are using (and sizes too) then i would appreciate it. I am sure i will keep posting different things about the process. Thanks for your help! :thumbsup:

hey all,

I have a 1996 xr 650 L that i use as a commuting road bike. I have it converted over to street use only and intend to keep it as only a road bike. my buddy and i tore it down to the frame last night to clean it.....well, we ended up taking the head off the engine too to investigate and see some stuff....thats what alcohol and persuasion can do sometimes!

Anyways, i am wanting to see what kinds of aftermarket cams everyone is using because i am going to get a new one. Also, my buddy is going to port and polish my head for me.....he is doing something different though. He is going to make the inlet side smaller so that it creates more velocity for fuel entering the combustion chamber.....same with the exhaust ports too i think.....anyone ever heard of doing this? he says that is what the top fuel bikes do??? Any comments before i let him do this?

Well, if you could let me know some of the cams you guys are using (and sizes too) then i would appreciate it. I am sure i will keep posting different things about the process. Thanks for your help! :thumbsup:

I'm very happy with the mid-top power the Hotcam stage 1 gave my L. Bottom end is virtually unchanged. It does remove the auto decompressor thhough. No problem cranking even wit hthe crf450x battery.

Porting a 650L head like a top fuel head may not be the best choice for commuting. Just gasket match it and smooth the exhaust side. Dont gasket match the exhaust either. That may create an EGR effect.

Top fuel bike engines are also purpose-built, giant v-twins with superchargers and run on nitromethane. It would be a big mistake to think that whatever porting works for those will work for a mild-mannered 650L. For the time being, I would recommend a conservative port cleanup like already mentioned.

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