super1c
Super Moderator
No other way to describe sound but is sounds as if my viper has developed a growel.. Not sure if its a low end burbble or what. This sound has no effect on performance, its not à bog. Usually happens after a longer run or longer corner to corner. I let off the throttle and if I start to ease back on the throttle I get a growling sound from exhaust. If I blip throttle and accelerate it clears right up? Almost seems worse when I have a idle hang. Recap, happens Mostly with small amount of throttle around 4-5 thousand rpm and worse with idle hang. All stock jets, fuel acres 2 turns out needles 4 groove both washers top. Plugs look good, pistons look book. Any ideas?
Might be a leaky head gasket...
brethren
New member
Could it be your exhaust manifold springs? I had to chance mine recently, I could actually see the pipes separating when I cracked the throttle. Mechanic even suggested putting 2 springs per side.
A couple of bucks
VIP Member
Is it like it's loading up at low RPM? Hate to mention the obvious...... How old are the plugs?
super1c
Super Moderator
Yes almost like its loading up. Plugs new this year and look good, 800 or so miles. And what's funny when I brought it up to the wife she said the same is happening to hers. So I'm now even more perplexed.
A couple of bucks
VIP Member
Change gas stations and mabey drop down to mid grade. Just throwing shtuff out there.
tippmannator
New member
Maybe bad seal between exhaust and can?
super1c
Super Moderator
No I'm sure exhaust seals are good. Good springs and joints copper sealed. Maybe it is a bog and I'm not picking up on it cause sled is moving? Hmmm I don't know but its driving me crazy
yamyrider
Active member
I am having the same issue with my 03 Viper. Same set up and I have the opticool gasket. I also have a idle hang with this growl that is driving me nuts. Doesn't sound like a well running Yamaha. I cleaned the carbs and that didn't help. Checked exhaust gaskets and all look good. I also get a bog if I hammer the throttle from a stand still.
super1c
Super Moderator
What about powervalves? Could sticking or stuck PV cause this?
brethren
New member
What about powervalves? Could sticking or stuck PV cause this?
Might very well be the power valves, 5000 to 6000 rpm is when the sound of the motor changes ( I think its a change in the position of the power valves). Are they clean? Have you adjusted the cables, or checked the operation with the servo cover removed?
super1c
Super Moderator
Might very well be the power valves, 5000 to 6000 rpm is when the sound of the motor changes ( I think its a change in the position of the power valves). Are they clean? Have you adjusted the cables, or checked the operation with the servo cover removed?
They were at the beginning of the season. But 8-900 mile later I'm sure not. Never happened before but always a first for dirty stuck or broken PV. Reason I'm looking for ideas is because sled is 2 hours away and I'm brainstorming for ideas for when I go back up.
A couple of bucks
VIP Member
Find something common on both. Because both of your sleds just started acting up at pretty much the same time.
A couple of bucks
VIP Member
Have you tried a different oil?Never happened before but always a first for dirty stuck or broken PV
Viktory2k1
VIP Member
I know this is way off but a possibility. If its just a sound and no other issues. Did you and your wife just get new helmets or hats or whatever you where under the helmet? I know this sounds weird but when I got a new helmet, all my sleds suddenly had "running issues". Like the helmet is filtering out a certain sound frequency.
I've had this with just a new balaclava.
Just a thought.
I've had this with just a new balaclava.
Just a thought.
super1c
Super Moderator
I did take the new helmet thing into consideration as we changed to 509 gear from modulars this year. Makes everything sound different when riding. But the sound has just developed. My moneys on PV's. New info from wife was top speed across lake was way down for her. So I'm guessing some dirty stuck valves if not pull throughs. Our riding has been a lot of slow trails this year as we have been a small group by ourselves or with big group. So maybe the gummed up faster this year. We will see.
yamyrider
Active member
I will clean my PV tonight after work and will post results. It is annoying when riding. I have not changed helmets and I started hearing the sound.
maxdlx
VIP Lifetime Member
Clean the power valves.
03viperguy
Moderator
power valves. mine used to do the same thing, was really noticeable with a bender can on it. could hear it a lot more. sounds like it is having at least one stuck open. loses low end and will bog for sure
super1c
Super Moderator
Thanks guys, now the waiting game. Have to work for next week so nothing till next Thursday. I'll drive myself crazy by then, haha!