2002 viper stock jetting I thought? Help please
I was just doing a carb cleaning on my 2002 viper and noticed the main jets were different than stock. The pto side said 140 on it the other two were 137.5
The sled is stock other than clutch kit and only used one layer of head gasket, as far is I know. Even if something else was modded wouldn't you want bigger jets not smaller? By the book mains were suppose to be 156.3, the pilots in it were the stock 145. What is going on here, ran fine last year but is it really leaned out?
I was just doing a carb cleaning on my 2002 viper and noticed the main jets were different than stock. The pto side said 140 on it the other two were 137.5
The sled is stock other than clutch kit and only used one layer of head gasket, as far is I know. Even if something else was modded wouldn't you want bigger jets not smaller? By the book mains were suppose to be 156.3, the pilots in it were the stock 145. What is going on here, ran fine last year but is it really leaned out?
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staggs65
Moderator
are you vented to atmosphere instead of the airbox?
What does that mean? Has stock airbox
staggs65
Moderator
do your carb vents tee together and connect to the airbox or are they just dangling and vented to atmosphere? venting to atmosphere requires smaller jetting than to the airbox
It has fitting that goes into the air box
staggs65
Moderator
seems like it'd be lean then. what altitude and temps do you ride? what did you plugs look like last year?
I'm in iowa I think its about 800ft above sea level. The plugs looked good I thought nice brown color except the pto plug was always a little darker and wetter which was the one jetted to 140. Maybe it's good I don't know just not close to what the book says is stock.
staggs65
Moderator
seems like quite a bit lower but if its been running fine 
hopefully someone with more Viper insight will chime in
hopefully someone with more Viper insight will chime inFrom what i can tell some one has put jets from a srx in it because 137.5 is not even listed in the parts catalog for a 2002 viper but they are for 2001 srx. Does any one think I should go back to the 156.3 or 155? The carbs are vipers, they say 8ek00 on them.
I could see that small of a jet in it for like grass drags or something but it wouldnt last too long in the winter with jets that small. The vent lines need to be plugged into the airbox right above carb rack like staggs said.
Something is up here thats jetted way,way, down from the stock 156.3, you sure you rode it in the winter like that, and maybe was running it on the grass or something and forgot to replace jets???
Something is up here thats jetted way,way, down from the stock 156.3, you sure you rode it in the winter like that, and maybe was running it on the grass or something and forgot to replace jets???
Nope I have never raced it. Some one else may have I bought it two years ago. I rode it all last year like that around 700 miles, and I am the only one that has worked on it since I got it, never checked jets till today. Figured they were stock, I was wrong. The vent line is plugged into air box. So i should go back to stock?
I would go back to stock mains. What are the pilot jets at now? What is the fuel screw set at?
The pilots are 145. I was at 2 turns on fuel screws.
pilots are 45, not 145.
mains stock would be 156.3 in all 3
needles at 3rd groove with both shims under clip
fuel screws out at 1-7/8-2 turns
those are the stock specs for you.
I do have some concerns when you talk about the headgasket with 1 layer and such and you rode this sled for 700 miles with grass drag jetting, doesnt add up to me, woulda been burned down many miles ago..............
mains stock would be 156.3 in all 3
needles at 3rd groove with both shims under clip
fuel screws out at 1-7/8-2 turns
those are the stock specs for you.
I do have some concerns when you talk about the headgasket with 1 layer and such and you rode this sled for 700 miles with grass drag jetting, doesnt add up to me, woulda been burned down many miles ago..............
Ya sorry I meant 45. Last year I didn't have the head gasket mod. Did that for this year. But 137.5 and 140 are what the main jets were because I never checked them til today since I bought it. I will go back to stock so I don't burn it down. Glad I noticed before it did.
Thanks for the help!
Thanks for the help!
I would suggest you put a stock headgasket back in it , a viper already has higher compression and the gas these days is absolute crap. The last thing I would do to a viper is peel the headgasket to add more compression along with the already high ign. timing, it will bite you in the rear with detotnation issues and cost you money for repairs ,
just tryin to save u a few bucks ahead of time. Good luck!
, just tryin to save u a few bucks ahead of time. Good luck!