yammitrip1
Member
idk been fighting my issue for 2 years now, I have just a piped viper stock everything, cant pull any weight in heel clickers no matter what I do for helix or rear spring. i have literally checked everything. Only thing i have left to check is my stator, screens in carbs and no sign of dimming lights for me nor gauge.
Ill be following this, hopefully you get it figured out
Ill be following this, hopefully you get it figured out
viperhauck
Member
Just to clarify. When I tested today i run with oem pipes and silencer. Need to try the big bore pipes soon
yammitrip1
Member
so your going to try with the pipes off from the price engine? or maybe even see if yamalars with let you borrow his pipes for a day?
does it ever reach 8500-8600rpm at all?
what jetting is in the 38mm carbs, pilots,needle setting and mains? what do the spark plugs look like?
what does it do with the 8dn20 weights,w/w/w/and the 52r46 helix with green at 60-70?
what gears are in the chaincase?
what jetting is in the 38mm carbs, pilots,needle setting and mains? what do the spark plugs look like?
what does it do with the 8dn20 weights,w/w/w/and the 52r46 helix with green at 60-70?
what gears are in the chaincase?
viperhauck
Member
Haha yamalars dont dare to let me get the hands on these pipes
viperhauck
Member
It doesent seems to matter how I clutch it. Its overrev in beginning. Typical 8800-9000 then it fall to 8500. When the sled reach approx 60mph its start do drop to 7800-8200rpm depending what clutching. Of course its terrible backshift in higher speeds.
For now the jetting is 380main. 45 pilot. Needle in middle. K&n filters but have of course tried oem airbox and lean it out down to 290 and thats to lean. For now the jetting is bit rich but not that much I THINK?
When I have the clutch setting you asking about is the same I described above.
Dont remember the gearing exactly now but it is viper oem
viperhauck
Member
It feels like it just dont have the final power on top......just flat with no edge
viperhauck
Member
Have also tried aaen pipes and no diffrence. Either better or worse
38mm carbs are not like the oem carbs as they use the hex jet a 380 main is the same as a 167.5 round jet, that way way too fat with stock pipes. 290 hex would be the same as a 150 main in the roundjet... alot closer to its needs, that engine should be running with 150-152.5 main jets with the stock airbox with stock yamaha carbs, 45 pilots with needles at 3.5 with 93 octane fuel.
what gas are you running in it also?
how about posting some pictures of the spark plugs after you run it good and hard??
its also possible too rich fuel curve thats why it could run worse when its warm because it becomes richer once the crankshaft and case is heated up.
I am pretty sure it wont be lean but try to ride it and just barely lift up on the choke and see if it gets better or worse....
what gas are you running in it also?
how about posting some pictures of the spark plugs after you run it good and hard??
its also possible too rich fuel curve thats why it could run worse when its warm because it becomes richer once the crankshaft and case is heated up.
I am pretty sure it wont be lean but try to ride it and just barely lift up on the choke and see if it gets better or worse....
viperhauck
Member
290 with oem airbox is lean...i know because i melted one piston with that. But even then I had the same issue with dropping rpms so it must be something else.
yamalars
Member
You've got that right..
Just kidding, ofcourse you can try them, but something is still wrong!Should run good with stockpipes to, only be down on power a tad but still make more hp than stock!?
viperhauck
Member
The spark plugs are a bit dark but not black. It could be leaner as I said. Run europe 98 octane. Thats 93 premium in us
ok, well octane should be good. Its not the pipes I will guarantee that they run good even with stock pipes up to 168hp. I still would like to see some pics of the spark plugs.
another idea: why dont you try both of Lars clutch,primary and secondary exactly how his is running now on yours and see if it does the same drop. If it drops the same then you have a engine problem, at least you will eliminate clutching from the picture.
have you checked and you sure you dont have air leak in the case halfs?
another idea: why dont you try both of Lars clutch,primary and secondary exactly how his is running now on yours and see if it does the same drop. If it drops the same then you have a engine problem, at least you will eliminate clutching from the picture.
have you checked and you sure you dont have air leak in the case halfs?
viperhauck
Member
Have not checked after airleaks in case....how do I check?
viperhauck
Member
I think its a engine/power problem. I tried 8ek weights and it still drops rpm....when i run lars srx it feels like that one have 30-40 hp more
do you still have your old cdi box from the viper 780?
case leak will show blackish residue from seam or you can spray it with brake clean or carb clean while running and it will change the rpm.
case leak will show blackish residue from seam or you can spray it with brake clean or carb clean while running and it will change the rpm.
viperhauck
Member
Havent check closely but havent seen any obviously. Crankseals are dry. Yes have severals viper cdi.
plug your viper cdi in and try it, leave jetting alone nothing but cdi in and see if it falls
viperhauck
Member
Do I dare to try that with now with my timing key?
ya, just make a short couple passes with it, it will tell you if its in the cdi box real quick it will also make up for the hjetting being so rich, dont ride it for a mile wide open.... like nice blips about 400-500ft long should tell you ,just watch the tach and see what it does.
u did put the keyway in the right way, it should have moved the flywheel clockwise looking at it from the mag side.
u did put the keyway in the right way, it should have moved the flywheel clockwise looking at it from the mag side.