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05 CRF450 exhaust

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I just bought a used 05 in good shape with the WB Aluminum Pro exhaust on it. My buddy has an 05 with the Big Gun EVO R full set on it. When riding them back to back my buddies bike is noticably faster (revs faster, more hit, etc.). Both bikes have had no engine work (stock) but he has the longer header that comes way out around the radiator hoses while mine is shorter like stock. Could this be the difference in power character or is it the Big Gun vs the WB? ...or something else perhaps. My bike is a lot smoother with almost no hit. The bike is still fast but it doesn't get the adrenalin pumping quite like my buddies bike.

What gives?:thumbsup:

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I have the Big Gun EVO R. It gives more power down low and mid range. I dont notice much difference in the top end, but I ride woods and ususally not way high in the rpm range. Are you sure you both have the same sprocket sizes? A bigger sprocket in the back will give more low end pull as well.

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normally the lowboy header gives more top end over rev.

Thats exactly what it does..it almost has a 2 stroke like hit; revs like hell right into the mid/top end..(I'm the guy with the other bike)

You need to jet your bike. The WB will give you more power, but will take more time to jet it.

He bought his bike from an MMI Mechanic who claimed the jetting was dead on..It cranks right up, there is no poping on decel and it does not seem to run overly hot or bog down..But I think your right in that it could be more than the exhaust..

So, we check the plug..and idle screw as mentioned in the sticky in the jetting forum...Run some fresh gas?? Make sure the trottle cables are tight??

What else?? :thumbsup:

Thanks for any input

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You need to jet your bike. The WB will give you more power, but will take more time to jet it.

I just got a 450R with a White Broths Aluminum Pro pipe, its very loud! and has great performance, but there is a flat spot in the really high RPM's, like if i give it full throttle in 5th it will bog a little then hit...

Im thinking its to lean, because the guy said he added both a K&N filter and a pipe and didnt re-jet the carb, because White Broths says you dont need to re-jet:prof:

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I just bought a used 05 in good shape with the WB Aluminum Pro exhaust on it. My buddy has an 05 with the Big Gun EVO R full set on it. When riding them back to back my buddies bike is noticably faster (revs faster, more hit, etc.). Both bikes have had no engine work (stock) but he has the longer header that comes way out around the radiator hoses while mine is shorter like stock. Could this be the difference in power character or is it the Big Gun vs the WB? ...or something else perhaps. My bike is a lot smoother with almost no hit. The bike is still fast but it doesn't get the adrenalin pumping quite like my buddies bike.

What gives?:thumbsup:

Could be the muffler you have needs to be repacked, or the bike needs a new piston or any number of things. I would verify the bike is as good as it can be in it's current state before I try buying expensive bolt on goodies. A new top-end really woke my '05 up with no other changes to the engine. Just a thought that might save you some money:thumbsup:

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I just got a 450R with a White Broths Aluminum Pro pipe, its very loud! and has great performance, but there is a flat spot in the really high RPM's, like if i give it full throttle in 5th it will bog a little then hit...

Im thinking its to lean, because the guy said he added both a K&N filter and a pipe and didnt re-jet the carb, because White Broths says you dont need to re-jet:prof:

Perhaps you need a Boysen Quickshot?

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Could be the muffler you have needs to be repacked, or the bike needs a new piston or any number of things. I would verify the bike is as good as it can be in it's current state before I try buying expensive bolt on goodies. A new top-end really woke my '05 up with no other changes to the engine. Just a thought that might save you some money:thumbsup:

What are some of the tells that it needs a top end? Yup..Pull it apart and go through everything before droppin any doe, for sure..:thumbsup:

Verifing that its as good as can be in its current state may need a new thread..but I'm guessing we start by cleaning out the carb, checking the lines and exhaust, jetting.. Any other areas or advise as to what we should look at??

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What are some of the tells that it needs a top end? Yup..Pull it apart and go through everything before droppin any doe, for sure..:thumbsup:

It is hard to tell the difference when you ride the bike day in, day out. The loss of performance is so gradual you don't realize it. I got about 200 hours on my original topend and honestly it still ran fine and did not smoke at all. There might have been a little increase in oil consumption, but not enough worry about. The throttle response and low end are much more abrupt now and it is much more quiet when running. I'll tell you something else I noticed. The spark plug gap had eroded on mine (original plug). These modern plugs with the tiny electrode are so good we neglect them, and mine was outside the maximum gap. My bad there for sure. This could have an adverse effect on performance as well, and is easily fixed.

P.S. I used the dry break in method discussed on this forum, and as skeptical as I was, I think they are on to something. If you do a topend, do a search and follow the procedure.

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