Let the mods begin on my Qlink XF200 - Page 8

Barnone · 12-17-2010, 05:51 PM

I installed the Yoshimura can that bennell put us on. There is a question that it is a real Yoshimura muffler but who knows?
Looks nice but I had to put a baffle in it to lower the noise.

Took a ride over to the dyno shop after I upped the size of the jets to 127.5 main and 35 pilot.

Compare the blue line and the red. Ignore the green since he was in a different gear than the blue run from last week.

Good improvement in the curve and up to 14.5HP. Dyno guy likes the fact that the dips were out. He thinks I can go up on the main. I do have a 130 so might try it later.

Bought another AFX (on sale for $60) full face helmet so he didn't charge me for the dyno run.

Weldangrind · 12-17-2010, 08:07 PM

14.5 is a nice improvement. I'm surprised that a 200 would support a 130 jet.

I can't see a red line. Only blue and green. :oops:

Barnone · 12-17-2010, 08:25 PM

W&G,
Operator error.
Your probably right that a 130 might be stretching it. I need to pull the plug and see what it looks like with the 127.5

Barnone · 01-03-2011, 06:05 PM

I took a 60 mile ride out in the country yesterday and with the 16 tooth front sprocket and on a long straight run only could get 7k RPM and 72 MPH indicated out of the bike. Plug clor looked good.
I'm going back to the 15 tooth sprocket and will give it another go. Will take my GPS this time.

david3921 · 01-03-2011, 06:53 PM

Bar, did you change the back as well. I (as others have) went with the 16T front and 45T rear. It make a huge difference on the top speed and also allows you to stay in first a bit longer. I set mine up for street riding though. You might want to keep the back at 48T if you go off road sometimes.

Barnone · 01-03-2011, 10:31 PM

david,
I just changed the front to 16. I'm feeling that I need to go back to the 15 since I can only pull 7K RPM in fifth gear and according to my dyno runs I am still gaining horsepower to 8 K RPM.
I put the 15 back on and will try the run again and post results.

FastDoc · 01-03-2011, 11:06 PM

Where was your peak HP on the dyno? If it was 7,000 you may be optimally geared now. Were you able to go any faster in 4th? BTW, on these little 200's, I use top speed as my porr man's dyno... :?

Barnone · 01-04-2011, 08:14 PM

FD,
Peak HP was 14.5 at 8K RPM,
I ran her up in 4th gear but didn't get good info.

Barnone · 01-09-2011, 01:58 PM

Took the Q for a run out in the country with the 15 tooth on the front. RPM went up to 7.5k (from 7K with 16 tooth) or so since it is such a small tachometer and top speed up to about 73MPH indicated.

Took my GPS with me to check the speedometer and it seems to be off by about 8 percent so 70 MPH indicated is really about 64 MPH or so.

Next test will be with the stock muffler because the currently installed muffler is just too loud.

Barnone · 01-10-2011, 03:36 PM

I replaced the Yoshimura muffler with the stock muffler because the Yosh can was just too loud for my taste and guess what?

I did my trip out to the country for a high speed (?) run and the performance improved a little bit. I can now ran at 75 MPH indicated which is probably really about a true 67 or so.

The Q sounds so much better now so I staying with the stock muffler.

Anybody want a Yoshimura(?) can?

FastDoc · 01-10-2011, 03:59 PM

I'm grateful that you are taking the time to share this data with us.

This confirms something I've thought for some time. Exhaust/intake mods may help the butt dyno, and driveability/throttle response etc, but do little to measurably significantly increase horsepower.

FastDoc · 01-10-2011, 04:02 PM

This reminds me of an old story.

A guy rides a small bike into the shop to get it souped up cheaply. The wise shop owner says that the fastest and least expensive way to gain real lasting performance you can feel is to......

Remove the gas cap, jack it up in the air.

Wheel a bigger motorcycle under the gas cap, and lower it into place.

Barnone · 01-10-2011, 05:46 PM

Yes, I've gone in a big circle.
Next is put the stock jets back in and try it again.

Weldangrind · 01-10-2011, 09:38 PM

We've had some excellent discussions about back pressure around here, and Reveeen has some good theory on the matter (as does TurboT's Dad, who was a career engine builder). Apparently, back pressure doesn't help if the intake side is optimized. Rather, an increasing pipe diameter is most beneficial to high horsepower (consider zoomies on a dragster, for example).

If you gained top speed by making a change, you gained horsepower. According to the logic preached at Hot Rod magazine, a change that decreases ET is an increase in torque, while a change that increases trap speed is an increase in horsepower.

That said (and this is all strictly theory on my part), the carb wasn't yet optimized for a free-flowing exhaust. Since you don't like the sound of the Yoshi, it sounds like you've reached the perfect balance between speed and sound.

Just my $0.02. I thrive on these discussions.

Barnone · 01-13-2011, 02:31 PM

W&G,
I was embarrassed riding such a noise maker so I staying with the stock muffler.

12-17-2010, 08:07 PM	#107
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	14.5 is a nice improvement. I'm surprised that a 200 would support a 130 jet. I can't see a red line. Only blue and green. :oops: __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

01-03-2011, 11:06 PM	#112
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	Where was your peak HP on the dyno? If it was 7,000 you may be optimally geared now. Were you able to go any faster in 4th? BTW, on these little 200's, I use top speed as my porr man's dyno... :? __________________ Happy to serve.
	0

01-10-2011, 03:59 PM	#116
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I'm grateful that you are taking the time to share this data with us. This confirms something I've thought for some time. Exhaust/intake mods may help the butt dyno, and driveability/throttle response etc, but do little to measurably significantly increase horsepower. __________________ Happy to serve.
	0

01-10-2011, 04:02 PM	#117
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	This reminds me of an old story. A guy rides a small bike into the shop to get it souped up cheaply. The wise shop owner says that the fastest and least expensive way to gain real lasting performance you can feel is to...... Remove the gas cap, jack it up in the air. Wheel a bigger motorcycle under the gas cap, and lower it into place. __________________ Happy to serve.
	0

01-10-2011, 09:38 PM	#119
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	We've had some excellent discussions about back pressure around here, and Reveeen has some good theory on the matter (as does TurboT's Dad, who was a career engine builder). Apparently, back pressure doesn't help if the intake side is optimized. Rather, an increasing pipe diameter is most beneficial to high horsepower (consider zoomies on a dragster, for example). If you gained top speed by making a change, you gained horsepower. According to the logic preached at Hot Rod magazine, a change that decreases ET is an increase in torque, while a change that increases trap speed is an increase in horsepower. That said (and this is all strictly theory on my part), the carb wasn't yet optimized for a free-flowing exhaust. Since you don't like the sound of the Yoshi, it sounds like you've reached the perfect balance between speed and sound. Just my $0.02. I thrive on these discussions. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

12-17-2010, 05:51 PM	#106
Barnone Join Date: Feb 2007 Posts: 1,354	I installed the Yoshimura can that bennell put us on. There is a question that it is a real Yoshimura muffler but who knows? Looks nice but I had to put a baffle in it to lower the noise. Took a ride over to the dyno shop after I upped the size of the jets to 127.5 main and 35 pilot. Compare the blue line and the red. Ignore the green since he was in a different gear than the blue run from last week. Good improvement in the curve and up to 14.5HP. Dyno guy likes the fact that the dips were out. He thinks I can go up on the main. I do have a 130 so might try it later. Bought another AFX (on sale for $60) full face helmet so he didn't charge me for the dyno run.
	0

12-17-2010, 08:25 PM	#108
Barnone Join Date: Feb 2007 Posts: 1,354	W&G, Operator error. Your probably right that a 130 might be stretching it. I need to pull the plug and see what it looks like with the 127.5
	0

01-03-2011, 06:05 PM	#109
Barnone Join Date: Feb 2007 Posts: 1,354	I took a 60 mile ride out in the country yesterday and with the 16 tooth front sprocket and on a long straight run only could get 7k RPM and 72 MPH indicated out of the bike. Plug clor looked good. I'm going back to the 15 tooth sprocket and will give it another go. Will take my GPS this time.
	0

01-03-2011, 06:53 PM	#110
david3921 Join Date: Feb 2009 Location: Michigan Posts: 1,032	Bar, did you change the back as well. I (as others have) went with the 16T front and 45T rear. It make a huge difference on the top speed and also allows you to stay in first a bit longer. I set mine up for street riding though. You might want to keep the back at 48T if you go off road sometimes.
	0

01-03-2011, 10:31 PM	#111
Barnone Join Date: Feb 2007 Posts: 1,354	david, I just changed the front to 16. I'm feeling that I need to go back to the 15 since I can only pull 7K RPM in fifth gear and according to my dyno runs I am still gaining horsepower to 8 K RPM. I put the 15 back on and will try the run again and post results.
	0

01-04-2011, 08:14 PM	#113
Barnone Join Date: Feb 2007 Posts: 1,354	FD, Peak HP was 14.5 at 8K RPM, I ran her up in 4th gear but didn't get good info.
	0

01-09-2011, 01:58 PM	#114
Barnone Join Date: Feb 2007 Posts: 1,354	Took the Q for a run out in the country with the 15 tooth on the front. RPM went up to 7.5k (from 7K with 16 tooth) or so since it is such a small tachometer and top speed up to about 73MPH indicated. Took my GPS with me to check the speedometer and it seems to be off by about 8 percent so 70 MPH indicated is really about 64 MPH or so. Next test will be with the stock muffler because the currently installed muffler is just too loud.
	0

01-10-2011, 03:36 PM	#115
Barnone Join Date: Feb 2007 Posts: 1,354	I replaced the Yoshimura muffler with the stock muffler because the Yosh can was just too loud for my taste and guess what? I did my trip out to the country for a high speed (?) run and the performance improved a little bit. I can now ran at 75 MPH indicated which is probably really about a true 67 or so. The Q sounds so much better now so I staying with the stock muffler. Anybody want a Yoshimura(?) can?
	0

01-10-2011, 05:46 PM	#118
Barnone Join Date: Feb 2007 Posts: 1,354	Yes, I've gone in a big circle. Next is put the stock jets back in and try it again.
	0

01-13-2011, 02:31 PM	#120
Barnone Join Date: Feb 2007 Posts: 1,354	W&G, I was embarrassed riding such a noise maker so I staying with the stock muffler.
	0