Engine breaking

[alaskanbowtie]

When in the mountains it's completely stupid to have that kind of engine braking, can cause a lot of dangerous situations!

I've found there's a lotta flatlanders here who don't recognize the danger of descending a hill at 100 mph on gravity alone and discover you have too much braking...yowzie! Just tapping the brake has been known to result in a huge yard-sale of snowmobile parts all over the side of the mountain! On trails it may be OK, but in the hills it can quite literally kill a guy...

I have no answer myself, but I certainly understand where you're coming from and why you'd want to fix it. I'm curious myself. Arctic Cat is advertising that they've designed a method of reducing this effect into their new 4 strokes somehow...I don't know details so I'm not sure if it's in the motor or the clutching on their end. So at least one of the mfrs out there recognizes it could be a legitimate problem....I given them credit for that, even if their sleds are green and ugly!

I have some memory of this being discussed last year and it was definitely a re-clutching that fixed it, hopefully eventually someone in the know will respond. As was already said, most of the real tuners are not frequenting these sites mid-summer...

>>>
I have know 4 stroke experience yet, BUT , I do know I'm quite accustomed to snapping the throttle for various reasons, not being able to do this will be a long hard habit to break. Sure eventually anyone can get used to anything, (ask inmates) I'd rather just fix it from the beginning and not have to worry about "OOPS", slipping off the throttle at the wrong time. If I want to dump the throttle right before leaving an edge for what ever reason, I can't , this is a problem for me. SO I for one would sure like a solid fix to do away with as much of the engine breaking as possible.

 

[Mongo 1]

Arctic Cat has a system that holds the throttle open slightly on deceleration, the testers said that it was very effective and that it gave the Z 1 a "two stroke feel".

 

[craze1cars]

Did some digging, found this quote on Snowest:

"I have a blu grn blu in mine. It brings up the engagement and it also disengages sooner allowing it to coast. It is a little easier to ride for me. I'd rather use the brake when I'm ready to slow down rather than when it tells me I need to. Maybe I just rode two strokes too long?"

Also found this thread on the RX-1 that mentions a clutch kit that fixed it on that sled:

http://www.ty4stroke.com/viewtopic.php? ... ne+braking

Seems to not be much else I could find....

 

[alaskanbowtie]

Did some digging, found this quote on Snowest:

"I have a blu grn blu in mine. It brings up the engagement and it also disengages sooner allowing it to coast. It is a little easier to ride for me. I'd rather use the brake when I'm ready to slow down rather than when it tells me I need to. Maybe I just rode two strokes too long?"

Also found this thread on the RX-1 that mentions a clutch kit that fixed it on that sled:

http://www.ty4stroke.com/viewtopic.php? ... ne+braking

Seems to not be much else I could find....

>>>
Blue , grn,blue.... is this a yamaha spring in the primary ? What is the engagement rpm's now ? I'd like mine around 4500 as long as it's smooth.

 

[craze1cars]

I quoted exactly what I found. There was no other info there, so I have no idea of the details...I don't even know what kind of sled he had, probably a trail sled so his answer would be of no benefit to your Apex Mt.

In my experience with clutch tuning, if you want to mess with clutching upgrades you need to forget about finding "answers" from strangers on the internet....there's a lot of made-up stuff and people wanting you to test their untested theories. And of course there's a select few who know exactly what they're talking about. Unfortunately it's almost impossible to sort one from the other. To make matters even worse, the ones who have actually found the BEST answers will NEVER post their answers on the internet for free...they make a name for themselves and then they sell them. And I've found they are worth buying. So IMO it is far better to contact a clutch tuner who is familiar with your sled (Yamaha), and explain every aspect of what your sled is doing now, and what parts of those aspects you want to change. That way you can buy all parts/kits from one source, have a baseline, and most importantly you'll have someone who will stand behind their recommendations and therefore allow you to exchange/trade/test off individual pieces as needed to help you keep costs under control.

Clutching has always been trial and error combined with individual preferences and compromises, all of which change constantly with the different weather, altitude, gearing, track length, lug length, rider weight, and snow conditions. That's how it always will be. It's nearly impossible to find straight answers for any sled without doing your own experimentation. A good clutch tuner will get you started with a good baseline.

I haven't found a good tuner yet for Yamaha becuase I just bought my first Yami in decades and am starting with baby steps all over again! So I dont' even have a baseline. But maybe someone else here can suggest a good Yamaha clutch tuner for you to work with...I promise it will make your life much easier than continuing the internet searches. If I were in your shoes, I'd start with some of the sponsors here...Ulmer comes to mind as one who seems to get consistent good reports on products he sells, but I have no personal experiences with him yet to confirm. And the fact you sound to me like a moutain rider may make things different yet...you need to find someone who knows how to clutch a mountain sled at your altitude, that throws even more wrenches into the mix that you'd never sort out without some experienced guidance.

 

[alaskanbowtie]

I quoted exactly what I found. There was no other info there, so I have no idea of the details...I don't even know what kind of sled he had, probably a trail sled so his answer would be of no benefit to your Apex Mt.

In my experience with clutch tuning MANY Ski-Doos over the past 20 years to my liking, if you want to mess with clutching upgrades you need to forget about finding "answers" from strangers on the internet....there's a lot of made-up stuff and people wanting you to test their untested theories. And of course there's a select few who know exactly what they're talking about. Unfortunately it's almost impossible to sort one from the other. To make matters even worse, the ones who have actually found the BEST answers will NEVER post their answers on the internet for free...they make a name for themselves and then they sell them. And I've found they are usually well worth buying. So IMO it is far better to contact a clutch tuner who is familiar with your sled (Yamaha), and explain every aspect of what your sled is doing now, and what parts of those aspects you want to change. That way you can buy all parts/kits from one source, have a baseline, and most importantly you'll have someone who will stand behind their recommendations and therefore allow you to exchange/trade/test off individual pieces as needed to help you keep costs under control.

Clutching has always been trial and error combined with individual preferences and compromises, all of which change constantly with the different weather, altitude, gearing, track length, lug length, rider weight, and snow conditions. That's how it always will be. It's nearly impossible to find straight answers for any sled without doing your own experimentation. A good clutch tuner will get you started with a good baseline.

I haven't found a good tuner yet for Yamaha becuase I just bought my first Yami in decades and am starting with baby steps all over again! So I dont' even have a baseline. But maybe someone else here can suggest a good Yamaha clutch tuner for you to work with...I promise it will make your life much easier than continuing the internet searches. If I were in your shoes, I'd start with some of the sponsors here...Ulmer comes to mind as one who seems to get consistent good reports on products he sells, but I have no personal experiences with him yet to confirm. And the fact you sound to me like a moutain rider may make things different yet...you need to find someone who knows how to clutch a mountain sled at your altitude, that throws even more wrenches into the mix that you'd never sort out without some experienced guidance.

>>>
Agreed , Ulmer was suppose to be working on some Mnt. stuff this year but I don't think that's done yet. I'll probably end up doing it myself, I would like to know a good starting point that a trusted user has used. Then I can go from there. I will also call the number listed in this post and talk with them on how they set up the clutches to eliminate the problem. I too have been around for many years , this isn't my first rodeo, i've found that for the most part the guys/gals on this site give solid information you can trust. Keep that in mind in the future!

 

[HAMMER]

 

[alaskanbowtie]

THX Hammer

 

[HAMMER]

What is your opinion on the increase of engagement rpms to around 4500

Try it and see if you like it... If you like the way your clutching feels/performs that's all that really matters... Clutching is mostly personal preference anyway... Unless you're clutching to compete in something specific like drag racing xxx distance and ET is all that matters or in a MPH contest and xxx top-end speed is all that matters... That's when the "little things" are critical and you have to be right-on-the-money to stay competitive.

 

[rxrider]

There are more to it than just clutching, running your track too tight sure doesn't help either cause it is adding to the rolling resistance, too much ski pressure will also add to the engine breaking.

 

[alaskanbowtie]

good points

There are more to it than just clutching, running your track too tight sure doesn't help either cause it is adding to the rolling resistance, too much ski pressure will also add to the engine breaking.

>>>
YES, your right, I'm a bit hessitant (sp?) to loosen the track to much with the cheesy Yamaha extrovert drivers. I don't want to round them off in the first 500 miles like some of the other guys. Can someone give me a reasonable amount of track sag in the middle that will allow easy track rotation but not destroy them to easy. Can I go looser than factory specs without a problem ? I'll be running 8" Fabcraft wheels on the rear so this should help a bit with track resistance.

 

[Grimm]

If you're interested in learning more about clutching characteristics (and you have a lot of time), then I suggest going to Dynamo Joe's website on clutching IQ. Highly informative.

http://www.mxzx-revzone.com/iq.htm

Happy reading.

 

[Mikey]

I will second that!

 

[Len Todd]

If the primary disengages, the engine will not brake the sled. So, if the clutch disengages at 4500 rpm (versus 3000) then there would be 1500 additional RPM that would not be braking the sled. I guess it is just a matter of how quick the RPM drops back to 4500. Might be worth a try. But, ... gettng traction at a 4500 RPM holeshot could be tough.

 

[BURMAD69]

After market clutching,External drivers,Loosen your track, Should help alot wont totally eliminate the problem but will make it less harsh.











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