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Louisvillestunts

Yzf cams in wr started wont turn over

12 posts in this topic

Basically i just bought the bike from flordia had jetting proublems me being in kentucky which brought me to this site , anyways heres my question i have yzf cams in my 05 wr450 the guy i got it from said the battery was bad and thats why it would turn over just clicking . And he told me something about the decompression pin on the wr cams being bigger thatn the yzf cams im thinking that has something to do with the starting proublem . The battery seems good on the oometer but havent really got it tested but did trickle charge it overnight at $160 not sure if should waste the money if its not gonna turn over anyways i hooked my new 636 battery to it same thing only a small rotation then clicking and its a good battery .

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Nah battery if its clicking, or try turning the engine over top dead center first, then try.

I just put YZ cam in mates bike on the week end. It works fine.....

ps. don't buy another Yuasa. You can get replacement gel cells with like 160cca for heaps cheap.

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The YZF exh cam dumps more compression while starting and will actually allow the motor to turn easier than WR exh cam when starting... the problem with installing the YZF cam in a WR is that the WR starter does not spin fast enuf to build up adequate compression while starting the bike. It might work.. I would not abandon the cams... they are not your problem anyways........If the bike kick starts and runs fine than you don't have anything cam related with your starter.

You could have a bad starter, relay, loose connection, resistance somewhere... sounds like dead battery, electrical issue or a starter that is not spinning freely.

Good Luck!

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I always cold start my WR by kicking it. The e-start just doesn't spin it fast enough. YZ cams make it worse.

When warm the e-start usually works but once in a while it will hang up on a compression stroke.

But the bike has much more power with the YZ cams so I leave them in.

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thanks for the help thought the battery was the proublem , but know the jetting is messing with me . i am currently runing a 52 for the pilot and a 175 for the main and clip on the needle is 1 from the bottom but i am lost on the air screw adjustment cant get it to idle at all, oh yea the bike has jardine full pipe and modified air box any help much appreciated . I belive 165 and 45 are stock on the jets is this correct?

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thanks for the help thought the battery was the proublem , but know the jetting is messing with me . i am currently runing a 52 for the pilot and a 175 for the main and clip on the needle is 1 from the bottom but i am lost on the air screw adjustment cant get it to idle at all, oh yea the bike has jardine full pipe and modified air box any help much appreciated . I belive 165 and 45 are stock on the jets is this correct?

Follow this link for sizing your pilot and setting your fuel screw.. it works awesome.

http://www.thumpertalk.com/forum/showthread.php?t=327405

Then check the jetting sticky in the WR performance forum you should something for your elevation and temp with the mods you listed.

Have fun! Atleast you have a steel frame bike:thumbsup:

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I agree with Don, but not beezer. I have an '05 with YZ exhaust cam and it starts easier (turns over faster) than it did stock. I'm not sure, but I think the new slip on exhaust helps also.

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I agree with Don, but not beezer. I have an '05 with YZ exhaust cam and it starts easier (turns over faster) than it did stock. I'm not sure, but I think the new slip on exhaust helps also.

I think I remember Don saying that he tried the yz cam while using the stock wr muffler, that could be a source of the problem. running an open pipe could make a difference. I guess I'll find out when I try installing the cam on my bike.

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I'll share an electical issue I had that shows you need to check everything, but this occurred before I installed the YZ cam so it had nothing to do with the cam and I'm sorry if this changes the subject of your thread.

I was taking a parade lap at a local race prior to the start when out of the blue my WR start running really crappy, missing, back firing, and eventually stopped. Had to push back to my truck and use my son's bike for the race as there wasn't enough time to dig into the problem. Couple weeks later after testing every possible electical component which passed, including that my three year old original battery was still good, I found the problem. Turns out the grey start button had rusted out from three years of washing the bike. Took it apart and it was all rusty inside and the small spring inside was broken probably causing a short. It was during this time that I learned that you can use the kill button as a start button, just swap out the plugs behind the number plate.

Don't know if this helps you out, I hate electrical issues.

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I agree with Don, but not beezer. I have an '05 with YZ exhaust cam and it starts easier (turns over faster) than it did stock. I'm not sure, but I think the new slip on exhaust helps also.

What would an exhaust pipe have to do with how fast the e-start turns the motor over?

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I think I remember Don saying that he tried the yz cam while using the stock wr muffler, that could be a source of the problem. running an open pipe could make a difference. I guess I'll find out when I try installing the cam on my bike.

"Turning over" and "starting" are two different things. With the YZF cams installed the biked "Turned over" much easier, reason being that it was dumping more compression... there in lies the problem with a WR and it's POS starter - it will not rotate the engine fast enuf to build up necessary compression while starting. The bike started awesome with the kick starter and it kicked much easier than it did with the WR cams installed... Just my observation...

The original poster claims the bike won't turn over at all and unless the cam shaft caps were over torqued his problem is not cam related.

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