Before you go & pull your carbs off, do a propane test of the crank seals, as well as the carb boots…I like the propane over the spray starter fluid…just connect a hose to regular plumbers propane bottle & pass the other end over the mag, pto & boots…you will know if there is a leak, the engine will surge…If no surge than set you fuel screw to 2 turns…2 turns out did not work for me when I had my surge or hang up, it was a bad mag seal…just to let you know…keep us posted…cheers
So tonight I took the fuel screws and pilot jets out, and blew compressed air through the passages. Then I set the fuel screws at 2 turns out. Put it all back together and once it warmed up a little it seemed to idle pretty good at about 1800 rpm - right where it should be. I revved it up to 4000 a few times and I don't think there's as much of a hang, but it still took 5-6 seconds to go from 4000 down to 1800. One time when I revved it up it came down to about 1500 and ran a little rougher, and when I gave it hard throttle it hesitated a little and backfired once. But after a few more times this went away and it idled at 1800 again. 
I had one of those little blow torches that attach to a gas bottle (now that I think of it it might not have been propane) but I passed that around both sides of the engine and the boots without any noticeable change. Did someone say you can do this with starting fluid also? I might want to try testing this again.
I had one of those little blow torches that attach to a gas bottle (now that I think of it it might not have been propane) but I passed that around both sides of the engine and the boots without any noticeable change. Did someone say you can do this with starting fluid also? I might want to try testing this again.
RTYsxv said:So tonight I took the fuel screws and pilot jets out, and blew compressed air through the passages. Then I set the fuel screws at 2 turns out. Put it all back together and once it warmed up a little it seemed to idle pretty good at about 1800 rpm - right where it should be. I revved it up to 4000 a few times and I don't think there's as much of a hang, but it still took 5-6 seconds to go from 4000 down to 1800. One time when I revved it up it came down to about 1500 and ran a little rougher, and when I gave it hard throttle it hesitated a little and backfired once. But after a few more times this went away and it idled at 1800 again.
I had one of those little blow torches that attach to a gas bottle (now that I think of it it might not have been propane) but I passed that around both sides of the engine and the boots without any noticeable change. Did someone say you can do this with starting fluid also? I might want to try testing this again.
Yes you can use starter fluid.. be careful not to hit the hot exhaust...I do not like the stuff...others do...just listen to what they have to say about it...
Did you pull the tops off the carbs & the floats out, when cleaning...?...
...keep us posted
no, I haven't messed with the floats or taken the tops off.
I'm thinking of opening the fuel screws another quarter turn and see what happens?
I'm thinking of opening the fuel screws another quarter turn and see what happens?
RTYsxv said:
I get angry at stuff like this...you really have to get into those carbs & CLEAN them good...I can't say this enough...it cost me a expensive rebuild last year...I took shortcuts=blown engine...it doesn't take much, bad fuel, low octane, snow/water...I trail ride 5-7 days at a time you never really know the fuel quality your getting, I cary boost & isopropal with me...if I have any doubt while out on that trip & made it home. I pull the carbs & give them a good cleaning...
nodoo_s
New member
do a search on hanging viper idle and you will see many posts on this subject. by the way 1800 idle will in most cases make your idle hang even with fuel screws turned out. at least it has on mine 1400 idle takes care of the issue. some dont agree with this technique but it works.
daman
New member
^ no i agee, lowering your idle will help in some situations..nodoo_s said:
but i thought he said idle screw is all the way out(witch is'nt right eather)
theblues said:
I spose I should take the rest of it apart, are there any tips or anything I need to know about cleaning the tops?
I have the fuel screws set at 2 turns out now, and it idles beautifully now once it's warmed up. So I think I have the pilot circuit straightened out.
There's a few inches of snow now, so I ran it around outside for awhile. Like I said it idles great, and it's got plenty of power, but I still have a nasty idle hang. If you give in any gas at all, it will go up to 3000rpm or more and take awhile to come down.
I'm wondering if it has something to do with the needles sticking or something like that, like they are coming down slowly so it takes awhile to get back to idle. Does that happen? Like my last post said, is there anything I should know before I take the tops of the carbs apart?
There's a few inches of snow now, so I ran it around outside for awhile. Like I said it idles great, and it's got plenty of power, but I still have a nasty idle hang. If you give in any gas at all, it will go up to 3000rpm or more and take awhile to come down.
I'm wondering if it has something to do with the needles sticking or something like that, like they are coming down slowly so it takes awhile to get back to idle. Does that happen? Like my last post said, is there anything I should know before I take the tops of the carbs apart?
daman
New member
when is the last time the carbs got tore right down jets pulled cleaned blew threw with shop air? do you have your throttle end play set right?
yamahaulinass
New member
what are the 3 screws on the motor side of the carbs supossed to be set at?>>
daman said:
The jets are clean - the only thing is I haven't opened the tops of the carbs. Everything on the bottom of the carb has been taken apart and cleaned.
I just took it out in the ditches a little while ago, probly put 10 miles on it and after that it seemed to idle down pretty well. I'm beginning to think there isn't really a problem anymore. It seems to run great.
daman
New member
well run her see what happens.RTYsxv said:
Well I think it's all good, except it backfires a little on idle, but it has done that since I bought it last winter. The dealer had gone thru it all and said it was ok. Would that mean I'm a little rich on the pilots at 2 turns out?
Thanks for all the info BTW...you guys have been a great help
Thanks for all the info BTW...you guys have been a great help
daman
New member
doess it BF on the carb side or the exhust..??
daman
New member
thats a good sighn of rich then...
so if I want to get rid of it, turn the fuel screws in a little? They're actually more like 2 1/8 turns out at the moment. I wouldn't think that this would cause any problems but it's kind of annoying to have the backfire