to start I have a 04 viper with cpr/hauck pipes. I also have hauck venom heads with unknown cc's ,supposable ported. I did a compression check 135 across the board on cold motor full throttle. ive been told jetting to the airbox is more consistant and I want to do that. I tried calling jeff(cpr) and he didn't know my cc # and kinda seemed like he didn't want to help. I called hauck and there telling me to run alittle fatter not knowing my cc's but unvented from the box. so im thinking of starting off 162.5 pto and center and 165 mag. 52.5 pilots at 2 turns hooked to airbox or 152.5 unhooked. also needles have been changed to 4 with clip on top and bottom on pto and center and both on bottom on mag. is this a safe starting point? also is there anyway I can tell my cc's without tearing it apart? thanks for any help, and of course always run premium
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snoprokidf6
Member
160, 160, 162.5 mains
needles at 4
I'm running a 47.5 pilot.
My engine is stock. This is jetted to the air box and it is far more consistent than when I tried jetting it to the atmosphere. I try this, make a pass or two on a cold day and go from there with your set up.
Off topic, I acquired a set of venom heads from another member, supposedly having 19 cc domes. Any chance are you running a stock Yamaha head gasket?
needles at 4
I'm running a 47.5 pilot.
My engine is stock. This is jetted to the air box and it is far more consistent than when I tried jetting it to the atmosphere. I try this, make a pass or two on a cold day and go from there with your set up.
Off topic, I acquired a set of venom heads from another member, supposedly having 19 cc domes. Any chance are you running a stock Yamaha head gasket?
Darcy
New member
How do I post on this cite
not really sure on what head gasket is on it. did the other member say if they were set up for trail or lake domes?
snoprokidf6
Member
Trail. Stock domes are 24,21,21. So to go from stock to 19 cc domes I figured that was waaaay too tight got pump gas. Anyways I put the heads on and my squish actually increased and compression went down. I split the head gasket, installed 1 layer and that brought my squish back to stock... Compression up to 135 in all three holes. I'm gonna measure these domes and see what they really are. I don't believe they are 19's.
ok mine were lake domes if that helps. do u know the cc's on them? im wondering if ours are the same since compression is 135 on both sleds
snoprokidf6
Member
I have no idea! I'm gonna pull the heads off and measure to see what my domes are.
did u have time to pull your heads yet?
snoprokidf6
Member
Yup. I live in pa. Heads are in ny getting measured
keep me posted please
snoprokidf6
Member
Domes are 24 cc's in all 3 holes. My compression measured with the stock head gasket was a tad lower than I'd like. Now once I placed on layer of the head gasket back in... I got 135 pounds of compression across the board. Your domes may be a little bit smaller. 23 or even 22.
snoprokidf6
Member
As far as your jetting questions I'd try what you were suggested by hauck. You should be safe, just keep a close eye on your plugs. Specifically on a cold night. Anytime I change jetting I will do several runs at 1/4, 1/2, 3/4 and wide open throttle for several hundred feet and check my plugs after each pull in all 3 holes to see where I'm at. Then I go for a trail ride lol.
thanks for keeping me posted I jetted to the airbox with 162.5 pto and center and 165 mag with 52.5 pilots at 2 turns. just rode around the yard seems to be ok. waiting on snow to test and see where Im at.
snoprokidf6
Member
No problem. If you find that those settings are a bit rich. Use the jetting I posted previously.
ratpack
Member
Has anyone tried using the Holzman ATAAC system on a piped viper?
You should start a new thread for this.