OK guys, just got done with a short 50 mile ride on my newer-to-me Viper I've been working on. Pulled the plugs and read the top of the pistons to get a general idea of what is going on.
PTO side plug looks like a 'trail friendly' plug - darker brown insulator, blacker/richer around sides and a silver ring around the electrode. Top of PTO piston looks nicely uniformly dark/tar color, not wet or built up. I think that is where I want to be.
The center and mag plugs look like what Mr. Viper would want for a race plug per his great article on reading plugs and wash. They look great (brownish insulator, dry). I don't want a race sled. I want insurance. The top of pistons on these two cylinders are darker around the outsides, but not uniformly across the top. In the middle top they look dry, flat colored silvery with slight darkening. There is no pitting at all, but there are like darker spotty areas in the middle silver field of the piston head.
Current setup is a stock Viper. I added the rear cooler. All needles are with clip in the 4th groove with 2 shims on top. All duel screws are 1-7/8 turns out (forgot to bump them to 2). I'm assuming stock main jets.
My riding is in the 35-60mph range usually, until I get areas where I can open it up, then I'm 70-80, higher if space allows. I'm in Wisconsin, so low elevation (~800ft) and ethanol occasionally. If I'm forced to use ethanol, I'm putting octane boost in. I clean my pilots and carbs at end and start of season.
I want to richen up the center and mag cylinders the right way. I want this sled to last. I love it and want insurance, not race performance. I should add that the sled ran flawlessly on this trip. Starts good, idles great, everything is great, so I don't want to lose that, just want to preserve it.
Here's my plan - please let me know if you think I'm on the right track or if I should be doing something differently: Leave PTO cylinder as is, so all this work would be on the middle and mag side cylinder: turn the fuel screws to at least 2, maybe 2-1/4 out, adjust needles to have one shim below and one above the clip. Should I be upping the main jets on these two as well? I know I'm probably not on them much, but is it good insurance? And here is a stupid question - main jet higher number is larger size? Never bought another jet so I don't know.
Also, my read on the cylinders is simply in the parking let after my ride with a LED wand light. I know accurate way is to chop during low/med/high carb circuits and read from there. Right now, I don't have the luxury to do that, so just want to get it safe for my next ride.
What do you guys think? Thanks in advance. Just told my wife we are only buying Yamahas from now on - because of this site!!!
Dan
PTO side plug looks like a 'trail friendly' plug - darker brown insulator, blacker/richer around sides and a silver ring around the electrode. Top of PTO piston looks nicely uniformly dark/tar color, not wet or built up. I think that is where I want to be.
The center and mag plugs look like what Mr. Viper would want for a race plug per his great article on reading plugs and wash. They look great (brownish insulator, dry). I don't want a race sled. I want insurance. The top of pistons on these two cylinders are darker around the outsides, but not uniformly across the top. In the middle top they look dry, flat colored silvery with slight darkening. There is no pitting at all, but there are like darker spotty areas in the middle silver field of the piston head.
Current setup is a stock Viper. I added the rear cooler. All needles are with clip in the 4th groove with 2 shims on top. All duel screws are 1-7/8 turns out (forgot to bump them to 2). I'm assuming stock main jets.
My riding is in the 35-60mph range usually, until I get areas where I can open it up, then I'm 70-80, higher if space allows. I'm in Wisconsin, so low elevation (~800ft) and ethanol occasionally. If I'm forced to use ethanol, I'm putting octane boost in. I clean my pilots and carbs at end and start of season.
I want to richen up the center and mag cylinders the right way. I want this sled to last. I love it and want insurance, not race performance. I should add that the sled ran flawlessly on this trip. Starts good, idles great, everything is great, so I don't want to lose that, just want to preserve it.
Here's my plan - please let me know if you think I'm on the right track or if I should be doing something differently: Leave PTO cylinder as is, so all this work would be on the middle and mag side cylinder: turn the fuel screws to at least 2, maybe 2-1/4 out, adjust needles to have one shim below and one above the clip. Should I be upping the main jets on these two as well? I know I'm probably not on them much, but is it good insurance? And here is a stupid question - main jet higher number is larger size? Never bought another jet so I don't know.
Also, my read on the cylinders is simply in the parking let after my ride with a LED wand light. I know accurate way is to chop during low/med/high carb circuits and read from there. Right now, I don't have the luxury to do that, so just want to get it safe for my next ride.
What do you guys think? Thanks in advance. Just told my wife we are only buying Yamahas from now on - because of this site!!!
Dan
Dan, when you buy main jets you are correct larger numbers = larger sizes. You will need to know which jets you have now, if you plan to purchase larger ones. Also in my opinion if you are only running on the needles now and your plugs look as they are, IDK if I would up the mains(just me)...klipper said:OK guys, just got done with a short 50 mile ride on my newer-to-me Viper I've been working on. Pulled the plugs and read the top of the pistons to get a general idea of what is going on.
PTO side plug looks like a 'trail friendly' plug - darker brown insulator, blacker/richer around sides and a silver ring around the electrode. Top of PTO piston looks nicely uniformly dark/tar color, not wet or built up. I think that is where I want to be.
The center and mag plugs look like what Mr. Viper would want for a race plug per his great article on reading plugs and wash. They look great (brownish insulator, dry). I don't want a race sled. I want insurance. The top of pistons on these two cylinders are darker around the outsides, but not uniformly across the top. In the middle top they look dry, flat colored silvery with slight darkening. There is no pitting at all, but there are like darker spotty areas in the middle silver field of the piston head.
Current setup is a stock Viper. I added the rear cooler. All needles are with clip in the 4th groove with 2 shims on top. All duel screws are 1-7/8 turns out (forgot to bump them to 2). I'm assuming stock main jets.
My riding is in the 35-60mph range usually, until I get areas where I can open it up, then I'm 70-80, higher if space allows. I'm in Wisconsin, so low elevation (~800ft) and ethanol occasionally. If I'm forced to use ethanol, I'm putting octane boost in. I clean my pilots and carbs at end and start of season.
I want to richen up the center and mag cylinders the right way. I want this sled to last. I love it and want insurance, not race performance. I should add that the sled ran flawlessly on this trip. Starts good, idles great, everything is great, so I don't want to lose that, just want to preserve it.
Here's my plan - please let me know if you think I'm on the right track or if I should be doing something differently: Leave PTO cylinder as is, so all this work would be on the middle and mag side cylinder: turn the fuel screws to at least 2, maybe 2-1/4 out, adjust needles to have one shim below and one above the clip. Should I be upping the main jets on these two as well? I know I'm probably not on them much, but is it good insurance? And here is a stupid question - main jet higher number is larger size? Never bought another jet so I don't know.
Also, my read on the cylinders is simply in the parking let after my ride with a LED wand light. I know accurate way is to chop during low/med/high carb circuits and read from there. Right now, I don't have the luxury to do that, so just want to get it safe for my next ride.
What do you guys think? Thanks in advance. Just told my wife we are only buying Yamahas from now on - because of this site!!!
On the pilot jets, if the sled starts fine and you dont have a bog or throttle hang you may be okay with the current settings as this is all the fuel screws control(idle and jsut off idle conditions).
You could adjust the needles to where the needle sits on one shim and try that if you need or feel you need to use both shims(your call). Also make sure you run decent fuel when you can. sounds like your on the right track.
Thanks for the reply Bandit. I do appreciate it! Got everything adjusted needle wise and screw wise, remount the rack tomorrow. Wish I had snow to test out the different circuits! Thanks again, Dan
Your Welcome. This is one of the reasons why TY is the BEST site on the Planet,(Plus Mr.Sled) wouldn't want it any other way.. Tracy