Riddle me this

[rhalloran]

Why is it that so many snowmobilers ride around on and off and on and off and on and off and on and off and on and off and on and off the throttle?

Vail Pass last weekend, it seemed that every other snowmobile that passed us IN THE PARKING LOT passed us BRAAAAP pause BRAAAP pause BRAAAAP pause BRAAAAP pause

Are they trying to get sympathy because they can't afford mufflers?

Seems that most of these people ALSO have blown-out cans.

What am I missing? Snowpacked, firm road, I find a speed and drive at it - what's the point of on/off/on/off/on/off?

Serious question - enough people do it that I'm not chalking it up to "buncha morons."

Is it a holdout from days of fouled plugs?

My sleds (everything from rotary valve late 90s things to new direct injection) don't mind constant throttle one bit.

?????

Does not really affect me either way (except the annoyingly loud ones), I just don't get it.

Help me out, snowest!

 

[Vailguy]

2 stroke engines (from what I have been taught by people smarter than me) do not like constant throttle positions outside of wot. That they can got hot spots in varying throttle positions. One would think that efi mapping would mitigate that vs. Tapered needles. Burping adds fuel&oil to lubricate/cool the rings. Now let the smarter people chime in.

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[rhalloran]

There's probably SOME truth to that.....

....but my Yamaha RZ350 (two stroke twin, carbs, oil injection) did not rack up 36k miles on the original pistons CONTINUALLY CYCLING the throttle. (and then I sold it....)

Cruising along the road - with a name like "Vailguy" you're probably familiar with the parking-lot-traveling-circus I'm speaking of - with a dramatic change in throttle EVERY THREE SECONDS (at most) seems excessive to me.

???????

 

[rhalloran]

Actually, that made me think of something.

I used to ride offroad motorcycles, and somewhere down the line, someone pointed out that coasting downhill with the throttle closed meant the engine was spinning pretty fast without much incoming oil.

On LONG descents, I'd hold the kill switch down and open the throttle, let it suck in a buncha fuel and oil.

No idea if it helped. None of my bikes (KTMs, mostly, one KX500) ever blew up.

I rode the KTMs on the street a fair bit, too, mostly commuting between trails, but many 20+ minute constant-speed (probably slightly varying throttle) pulls on 285 or 50 or whatever.

Not buying the need to "burp" it every fifteen feet in the parking lot for engine preservation.

hrmph.

 

[Drewd]

Loud pipes save lives. Oops, sorry...wrong sport.

 

[Vailguy]

Yes, very familiar with the parking lot Rockstar exhibit that is vailpass, and that is why I have only been there once in the last 3 years. As far as the bikes go... Don't know, my KTM is a 450


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[Drewd]

All of those 2 stroke ultralight fliers must be doing it wrong, e.g. using constant throttle setting. They don't have as much to lose though as a sledder if an engine fails.

Got a 2 stroke generator that has hundreds of hours on it running constantly at 3600 rpm...never a problem.

My convertible's engine is similar to a 2 stroke engine; it has no valves, develops its power at high rpms, and is oil injected, should I be concerned that I use cruise control?

 

[Vailguy]

Hmm... Come to think of it, I have a old vintage Vespa. Piston ported design, fan cooled. Many hours at a half throttle position. If you look at me Piston break in theory, it varies as well. Some say varying throttle for the first hundred miles. Some say 15 minutes and drive it like you stole it. Up to the user I guess, so then you have to look at the venue :/

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[OuraySledder]

Well... I am a throttle burper.

My last two sleds have had stock cans so I do not do it for entertainment value. My guess is that many of the other burpers are burping for the same reason I am, we think it is the proper way to operate a two stroke.

My particular sled is the brand with the most fragile engine. I have turned the oil up and I avoid constant throttle settings. There is definately a lean section of mapping in the midrange. This is how they pass the EPA tests. I know that lean conditions create heat. Heat ruins the junk stock pistons. I am trying to avoid that.

I have ridden like this for 20 some years. Maybe you are right and it is completely unnecessary. Worse yet, it almost certainly wears the clutches out more quickly to be a burper.

Who really knows? I have not yet witnessed the VP circus. Much lower population in our parking lots. Just know that they may not just be show ponies, it may be legitimate.

 

[winsa12]

When I was in the second grade my grandfather found a Yamaha PW80 in the trash. The previous owner had never put 2 stroke oil in it. My dad had the engine rebuilt and I had a dirt bike. I distinctly remember him telling me to not run it at constant throttle for an extended period of time. I do not remember him telling me that I don't need to burp it after the break in. I am willing to bet a lot of guys do this because there dealer says to. They just don't know they can stop being asshats. They also do it cause they like the noise. The triple triple sleds are the worse, AC ZRT's are notoriously bad in my experience.

This is a big problem out east where we ride hundreds of miles a day on flat groomed trails. One guy burping his engine will make a bump, then the next hits it and drops some lose snow out of the tunnel. After 100 sleds the trail is trashed until the next groomer run.

 

[snowmobiler]

last weekend we had a richy newb on a straight piped 4s yamaha burping every 2 seconds through the snowpark.you could probably hear it for 5 miles.we all laughed.what a dork.LOL

 

[rhalloran]

OK, so bad jetting/fuel injection settings can create a "need" for it.

I'd forgotten about ultralights...they really do use a set throttle. Hmmm.

 

[m8braaaap]

What the op heard was a pinned polaris! That's what they sound like wide open! Lol

 

[tudizzle]

I am a throttle blipper...not really in the lot but the rest of my ride. Has nothing to do with sound or trying to get attention.

When side hilling it increases the track speed in bursts...resetting the track on my line...this allows me to hold more concise lines for longer periods. I am also a break and throttle in conjunction guy which some don't understand. But when they do...they get it.


Honestly I don't pay attention to what others do. Certainly not enough to effect me in such a way that it sticks in my head and I have to go start a thread about it.

I don't let others effect my life that much Kinda goes along the line of letting how people park effect me. Life is too short to worry about those little things.

 

[rhalloran]

Honestly I don't pay attention to what others do.

Kinda hard not to when they do it 5 feet from you!

I've never noticed it on the hill, too many variables - sometimes off then on then off is required.

Snowpacked road....ehhh?

The king of throttle blippers was the dbag who climbed up on the snowbank & roosted my truck full of snow. uhhh, knockitoff...THAT'S not cool.

That was different, though, but also hard to ignore.

 

[JDUB39]

I confess as well... I am a throttle "burper"... I just do it to warm up my throttle cable on cold days. (...joking)

Not sure why people do it, not sure if there is a rhyme or reason. I doubt the sales guys at the powersports places tell you to burp the throttle the whole way through the parking lot.


Just a Tudizzle stated - Don't let idiots ruin your day!!

 

[backcountryislife]

It's not a matter of idiots, it's to a certain extent a matter of stock or mod.

Even stock, there have been sleds that will burn down from a particular throttle position held for a while, the 07 1000 was a very recent, EFI example of that. It took a stupid long time at just under PV opening to do it, but it did happen & it spurred a flash to the ECU as a result.


Mod sleds though, rarely have "perfect" mapping, so they shouldn't be held at any one position. Most of us that have run mods sleds, retain that habit, even though we're riding a panzy stock azz sled... hard to break us of it

As to the "where"... a snowpacked road is EXACTLY where you need to do it the most. Most sleds are tuned well at idle, and WFO, but it's the inbetween that is tough to dial in, so since you can't always hammer down on the trail, you need to vary throttle position.


The ultralight is a great example of "tuned for that position". We could get just about ANY one spot in the map perfect if we spent the time at it, so that it could run for hours that way. If I had a setting that would set me to 6700 exactly, you can bet in about 3 tries I'd have that ONE spot perfect... but the rest of the powerband is still there to deal with.

Also spinning the track on that snowpacked road, rather than idly driving down it, kicks up snow onto coolers, hifax...


In other words... there's very much a specific purpose, even though it may not ALWAYS apply, it's not just for fun.


I could hop on any of my last 5 or so sleds & burn them down in a matter of a minute by simply holding them at one particular spot.... hop on any turbo, hold it at say 5500 to 6500 and see what it thinks about that

 

[rhalloran]

whatevarrrrr if some hotrod mod sled can't deal with a certain RPM for more than, say, TEN SECONDS at a time, there's a Problem. I get hotspots, lean spots, spots between slide and needle, pilot and main...but ragged edge enough to make every 2-4 *seconds* required? ick.

I'm sure you'll take every opportunity to annoy me with it, though.

I'd get tired of on-off-on-off-on-off-on-off-on-off for a 20 mile commute to the goods.

I knew a FLAMING gay guy who drove like that, last name was Champagne (kid you not), he drove like that, because he thought it was more fuel efficient. On the throttle, 66mph, off to 64, on to 66, off to 64...and over and over and over.

Correlation? Perhaps.

I think I'll go with that.

 

[rotax]

I did/do it for break-in/warm-up. And for long mid-range runs down the trail/road.
If you ever have to own a Polaris engine, you'll understand.. =\

That, and I'll use the 'braap n brake' method as a sidehill technique as well, but in that kinda situation its for sled control or descent control, not engine preservation.

 

[backcountryislife]

whatevarrrrr if some hotrod mod sled can't deal with a certain RPM for more than, say, TEN SECONDS at a time, there's a Problem. I get hotspots, lean spots, spots between slide and needle, pilot and main...but ragged edge enough to make every 2-4 *seconds* required? ick.

I'm sure you'll take every opportunity to annoy me with it, though.

I'd get tired of on-off-on-off-on-off-on-off-on-off for a 20 mile commute to the goods.

I knew a FLAMING gay guy who drove like that, last name was Champagne (kid you not), he drove like that, because he thought it was more fuel efficient. On the throttle, 66mph, off to 64, on to 66, off to 64...and over and over and over.

Correlation? Perhaps.

I think I'll go with that.

well... now that I KNOW... oh I most definitely will next time I see you guys!!!


2-4 seconds, no... but 10 seconds at one of the hotspots, I could see that being on the edge. On my 07 1000 at 6500 or so egt would climb to 1280 or so just in a few seconds, but if you added fuel there, it ran like azz. Really sucked.


I've got a can on my XM now, I'll be looking for you guys...