What do we know? Quite a bit.
The Raptor Rip Offs are a varying crew, especially the $12 and below ones.
They were built for smaller bikes, have smaller outlet tubing sizes and smaller internal passages. They do have the right flange though and will bolt right on up to the Savage tank holes.
They will likely have shorter main and reserve pipe heights. (intended for smaller tanks after all) They will all give you much less reserve gasoline capacity than a stock petcock and most will give you less than a real 660 Raptor petcock does.
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What symptoms do they show when they are put into use?They all give you reduced reserve capacity.They like to leak at the tube/nipple junction -- some say "So what, just put a tubing clamp on it and get on with your life".
They don't flow as much fuel as fast as the full sized 660 Raptor does. This only becomes problematical when you hit reserve and have empty bowl and lots of air in the system.
Air in the system is a bad thing for petcocks, air must move back up the pipe in exact equal volumes to the gasoline moving down the pipe (must, it is pipe hydrodynamics 101). Funtionally, this cuts your fuel delivery in half during the time the system is passing air.
During this protracted air passing portion (just after you ran out of gas and went to reserve) the cheapie rip-off Raptor's smaller internal passages take you past the point you can keep up with up/down gasoline flow enough to keep your bike happy at full throttle. Your bike chokes and stutters a fair amount of time right about then because of this.
So, do the cheapie rip-off Raptors work? Have to give a VERY qualified yes to that, given that you remember to use a tubing clamp with them.
Do they work as well as a Raptor? No, they do not -- it is not a good idea to run your engine in a partially fuel starved condition for any protracted period of time.
We have partial proof that the stock petcock starvation issues can contribute to upper ring groove collapse and early onset oil usage.
We have two dead motors that seem to show some chicken and egg type proof that the piston scuffing damage might have been associated with lean running conditions which certainly can point back to the stock petcock having fuel starving the engine shortly before death occurred.
Continuing this sort of half fuel starved action with an undersized internal passage Chinese raptor rip off doesn't seem to be very smart.
Plus, the Chinese rip offs lack the outer "O" ring underneath the change lever plate which means any little internal edge flaw in the selector "smiley rubber" can make a slow fuel dripper out of the rip off petcock, whereas the real 660 Raptor would contain all such small dribbles internally and not pose any form of fuel drip issue. That large diameter outer containment rubber "O" ring is there for a reason after all.
Gasoline dripping out of the rip off petcock and hitting the hot engine poses a potential fire hazard while riding ...... but it gets worse when you get home and put it in the garage.
Having it do the slow drip thing in your garage is especially bad, since your gas hot water heater might live in the corner of that same garage and gas fumes like to spread out over the floor at knee level naturally.
Whoosh !!!
Save $10 and potentially mebbe hurt your engine or take an outside chance of burning your silly house down --- a false economy there, I think.
One of you Moderator types please put this up in Tech somewhere, on a main Raptor reference would be nice so folks won't keep chasing down the wrong path to get themselves a Raptor type petcock. Ebay will lead them to an undersized raptor type much quicker than it will lead them to the real deal, much quicker.
These guys keep asking after the fact because we don't tell them clearly enough BEFORE the fact ....