Sign in to follow this  
Followers 0
kfugate

yz450 power problems

22 posts in this topic

so i just went out and got a 08 yz450f, the only problem is the power. i switched from a 06 crf450 and the yz's stock power just doesn't match up. i keep reading about switching out the exhaust to get more power, but is there anything anyone knows about that doesn't involve doing that?

Share this post


Link to post
Share on other sites

I have a friend who took out a couple of the cones inside the muffler, After that it seemed to run as good or better than my 07.

Share this post


Link to post
Share on other sites

No offense, but, have you tried one. Believe it or not it works. I have 2 very fast, very loyal yamaha , long term racer friends, and they dont use stuff that doesnt work, and it works.

Try it and give us a report.

Share this post


Link to post
Share on other sites

that is sum funny shit lol...

but anyway, kfugate, how much better turnin is the 08 than the 06?

Share this post


Link to post
Share on other sites
2 simple things to bring it back up to snuff,

Aftermarket silencer and boyesen x wing and its right back to where you want to be.

I would like to see a dyno test of that crap, those tornado fuel saver paperweights do nothing to increase fuel milage or increase power and the x-wing is the same paperweight. I have seen lost of customers fall victim to that crap.

Post some proof that they actually work

Share this post


Link to post
Share on other sites

No need to be quite that contentious.

Dividing the intake air stream into multiple levels horizontally on the atmospheric side of the carb by placing thin "wings" in the mouth of the carb back to the slide does reduce turbulence directly in front of the slide at throttle openings from 1/8 to 1/2, and in some smaller, very highly tuned engines, such as the typical YZ250F, such a device can improve the crispness and throttle response at part throttle.

However, because the YZ450 is in a lower state of tune, it benefits from such things much less, and in most cases, will do no more than mask the real jetting issue leading to whatever complaint you may have. In any case, the appliance accomplishes nothing at all at full throttle, and cannot increase power.

Share this post


Link to post
Share on other sites

so would my 250F actually benefit from usin this wing thing? or is it something like the boyeson quick shot that i have already installed?

Share this post


Link to post
Share on other sites
so would my 250F actually benefit from usin this wing thing?
Mine did, but as I say, only in terms of sharper carburetion at lower throttle openings.

Share this post


Link to post
Share on other sites
I would like to see a dyno test of that crap, those tornado fuel saver paperweights do nothing to increase fuel milage or increase power and the x-wing is the same paperweight. I have seen lost of customers fall victim to that crap.

Post some proof that they actually work

TRY IT INSTEAD OF BEING SUCH AN ANGRY YOUNG MAN. I HAVE 2 FRIENDS WITH 08'S AND THEY ARE FRUGAL, TO SAY THE LEAST AND THEY BOTH HAVE THEM AND THEY SWEAR BY THEM. IM NOT ONE TO SAY SOMETHING WORKS OR DOESNT WORK, UNTIL I TRY IT.

Share this post


Link to post
Share on other sites

.

I would like to see a dyno test of that crap, those tornado fuel saver paperweights do nothing to increase fuel milage or increase power and the x-wing is the same paperweight. I have seen lost of customers fall victim to that crap.

Post some proof that they actually work

These "Powernow" thingies are essentially the same as the Boyeson wing you are talking about.

Proof ...ok then, here you go....

For the record .... I don't own or run one of these, but this dyno printout has me wondering if I shouldn't buy one to try!

(They should give me a free one for posting this here!!)

powernow_dynocharts.gif

..... and yes, I too would like to see the printout for full throttle opening performance, but it wasn't on their website for some reason!

Greg

Share this post


Link to post
Share on other sites

I've used a powernow on my 250F, it made a slight difference up to half throttle for crispness, as grey said, but i also tried one in my 450...didn't make a difference in my opinion.

Share this post


Link to post
Share on other sites
..... and yes, I too would like to see the printout for full throttle opening performance, but it wasn't on their website for some reason!

Gee, I can't guess why. :thumbsup:

I did see a charted run that showed a loss of 0.8 at peak on a CRF450. If the peak is near the same, has it occurred to anyone that the part throttle gains can be matched without the device by opening the throttle farther? Just a thought.

At least in a 450, you should be able to accomplish as much with correct jetting.

Share this post


Link to post
Share on other sites

.

has it occurred to anyone that the part throttle gains can be matched without the device by opening the throttle farther?

Yes, good point Gray!

I wonder how these levels of throttle opening were monitored?

Were they precisely at 1/4 and 1/2 throttle?

If the slide was 1mm higher than it should be then this could increase flow by as much as 2 or 3%.

Greg

Share this post


Link to post
Share on other sites

I wonder how these levels of throttle opening were monitored?

Were they precisely at 1/4 and 1/2 throttle?

If the slide was 1mm higher than it should be then this could increase flow by as much as 2 or 3%.

They would have to have been stopped mechanically to be accurate. Even marking the throttle would be subject to a significant error.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0