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Parx_400

WR E-Start and YZ Cam

18 posts in this topic

Hi everyone.

I have read allot of posts here about the Estart and using a YZ cam. Some people have had issues with them an d the Estart would not work. Has there been any closure on this issue? I have a 05 Wr450 and since i need to adjust the valves I was going to throw a YZ cam in there. I wanted to make sure its going to work first.

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I ran a YZ cam in my '04 for 5 years with no problem. I suspect some of the problems may have been more jetting related. The estart doesn't spin the motor very fast so it's a little more picky about starting if the jetting is way off. That said I currently have 3 WR450's (03, 04 and an 08). The 08 starts the best maybe because it's new but both the 03 (wr cam) and the 04 (yz cam) estart just fine. Honestly I can't tell any difference in the way they start. Of course where I live it doesn't get very cold. The few times I've ridden in cold weather I've had to kickstart the first start of the day but estart was fine after that.

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I ran a YZ cam in my '04 for 5 years with no problem. I suspect some of the problems may have been more jetting related. The estart doesn't spin the motor very fast so it's a little more picky about starting

I have 06 yz cams on my 07 wr. I found the same thing, the motor spins slower with the yz cams, so the bike is a little more finicky about starting with the e-start. As long as you have a free-flowing exhaust and tweak your jetting a little bit, you should be fine. Mine actually starts easier with e-start when cold than when it is hot. After learning the proper starting ritual with the yz cams, my bike starts up fine with e-start 99.9% of the time.

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This is from the hot cams website

Can I use the 4022-1E Hot Cam for the YZF450 in my WR450 or YFZ450?

No, the 4022-1E and the 4044-1E cams have the identical cam profile. The only difference is the decompression pin height. The pin height is shorter for the engines with electric start. The electric starter will not turn the engine (with stock compression) over fast enough to build enough compression to start.

So the YZ exhaust cam is dumping too much compression for E-start.

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This is from the hot cams website

Can I use the 4022-1E Hot Cam for the YZF450 in my WR450 or YFZ450?

No, the 4022-1E and the 4044-1E cams have the identical cam profile. The only difference is the decompression pin height. The pin height is shorter for the engines with electric start. The electric starter will not turn the engine (with stock compression) over fast enough to build enough compression to start.

So the YZ exhaust cam is dumping too much compression for E-start.

yes, it does dump more compression. It makes the e-start a little more finicky, but not impossible to start. The key is good jetting and an open exhaust pipe.

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I have a YZ exhaust cam on my 09 WR450 and I had one on my 04 WR450, I agree its alittle more picky to start with the estart, I ushally have to kickstart mine when its cold (I am from colorado) when it's warmed up the estart is fine. It won't work quite as good as it does with the stock WR cam, but with the performance you gain from the YZ cam it's a small price to pay:thumbsup:

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"finicky" is not the word I would use...:busted:

I have no experience in anything older than a 07Wr w/ 06 YZF cams. BUT.... if I had it to do all over again, I would spend a little more cash on the hotcams. and likely wiil:ride:

The 05 WR's and YZ's shared the same intake cam p/n's correct?

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The 05 WR's and YZ's shared the same intake cam p/n's correct?

That is true. And the exhaust cam numbers for both '03-'05 models were different for the WR and YZ, but were the same within each of those models for all three years. The later ones are different.

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Thats for the help guys. Im going to get an 06 YZ cam for it since everyone seems to rave about those.

BTW, how tight do valves have to be before they make contact with the piston?

My Exhaust valves are both .18mm, .20 is the low end of spec. I'm going to adjust them next weekend but want to know if I can go for a short street ride tomorrow.

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Thats for the help guys. Im going to get an 06 YZ cam for it since everyone seems to rave about those.

BTW, how tight do valves have to be before they make contact with the piston?

My Exhaust valves are both .18mm, .20 is the low end of spec. I'm going to adjust them next weekend but want to know if I can go for a short street ride tomorrow.

dont the new generation alloy frames use a different head i.e. different cams? (06 yz +)

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dont the new generation alloy frames use a different head i.e. different cams? (06 yz +)

That was my question as well...

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The head is different (oils internally). The cams are different grinds/timings, but they physically fit either head.

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Just an update, my 05 with the 8 cell ebatt turns it over just fine.

Care to update? What exhaust you end up with? You like the power?

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