One of the best explanations I’ve seen

With all due respect i have been building and tunning two stroke engines for mor than 60 years and I take exception with your explanation. The power valve in any two stroke is a variable timing exhaust valve. When the valve is closed the engine preforms more like an enduro with higher compression and a longer power stroke. when the valve opens the compression is lessened and we move more exhaust out which creates more revs. You want high compression for torque and less so the engine can rev. In the old days you would widen and raise the exhaust port to gain horsepower, but we would loose bottom end torque. The power valve gave us the best of both worlds which we didn't think was possible at the time.

@4x4American

5 ай бұрын

What makes the exhaust valve open is what I wanna know, is it pressure in the engine?

Little late to the vid, Great explication! You picked up a new follower w this one

@tspmoto1134

3 жыл бұрын

Thanks!

Great video. Right to the point. That other bald guy is quite long winded ;)

@harisyoung4110

2 жыл бұрын

Which bald guy ? the guy on "dirtbike channel" ?

Thank you!! Great video.. You got yourself a new follower.

@tspmoto1134

5 жыл бұрын

glad you liked it!

Very informative thanks!

That's an awesome video..

Tq for sharing good info

Any mods like this for a 80-125cc 2 stroke? I love the weight of the 2 strokes as a wife bike but the 2 stroke MX hit is really undesirable for a trail bike. Let me know what ideas you have?

I am a visual learner, thanks Tyler. Have you done or could you do a video on setting a baseline for the valve and how to adjust for stock and performance pipes and reeds. Thanks again.

@tspmoto1134

4 жыл бұрын

To set the true baseline you need an rpm guage. The valve should start to open at 5,500 rpm. or just turn the screw in 1/8 in from flush.

So basically How I can adjust it if I want to use the KTM 300 two-stroke for the street do I do I have to bring it out or in

Great video!

@tspmoto1134

5 жыл бұрын

Hey thanks!

@mikeshem7665

5 жыл бұрын

@@tspmoto1134 No problem, it is a great video tutorial. I did notice some negative nonsense in the comments. But regardless of that I'm positive that anyone with a KTM or a Husqvarna that wasn't sure how easy it is to adjust the power valve, if they saw the video is aware now. I think it's awesome that some riders still share with others.

whoop!

If I ride a 250 tc on some hare scrambles tight stuff what option on spring and adjustments ? Any thoughts is there a trail red? Not sure i heard that - thx

@tspmoto1134

4 жыл бұрын

You really just have to experiment with it. A stiffer spring might feel a bit more predictable in the tight stuff

You might wanna change the name to Ktm and husky only, none of the other 2 strokes have the custom springs, but great video.

@tspmoto1134

5 жыл бұрын

That is a good point I will do that

@DAVIDMLIBONATI

5 жыл бұрын

Beta 2 strokes have the same 3 spring adjustments choices.

@johnnyvanpottelberghe

3 жыл бұрын

@@DAVIDMLIBONATI does this works for beta also??

Whats the stock preload for Ktm/husq 300 17 carb?

@tspmoto1134

2 жыл бұрын

the screw is set at about 1/8 in or so it starts to open at 5500 rpm

My KTM 150 exc power valve opens at about 18000 rpm so ima unscrew it a bit yO

The power valve alters port timing not back pressure.

@tspmoto1134

4 жыл бұрын

Yes it delays the pressure coming out of the cylinder by changing exhaust port timing. I try to keep things understandable. Concepts

@brycedavis907

4 жыл бұрын

I also has a substantial effect on intake charge and static compression. My personal opinion is that it would have been much more credible to just state that raising the port height adds top end power. Trying to simplify a complex idea doesn't make it easier to understand.

@tspmoto1134

4 жыл бұрын

I was mostly trying to explain how to make adjustments without making the video to overwhelming. Most people don't care about the nitty gritty, they just want to change a spring and turn the screw to make themselves feel better.

@tspmoto1134

4 жыл бұрын

Don't get me wrong I do appreciate your criticism and you are right. I will consider that for future how to videos

@brycedavis907

4 жыл бұрын

No hard feelings on my part, if anything came across as petty or condescending, I apologise. My intent was to provide constructive criticism.

please forget that fucking "backpressure" word... power valves partially close the exhaust channel to simulate a shorter exhaust opening (in crankshaft degrees), because at low rpm's there is not much exhaust gas volume that needs to be evacuated, this effectively increases the power stroke some 10-20° longer so each and every combustion process has more time to push the piston down. that's why this gives you more power in low-midrange.

Now every1 is going 2 go think there mechanics & mess up there bikes

Beck preshure ? Wtf hahahah