1993 VFR 750 week on power

motocrossscott62 · 06-22-2008, 10:04 AM

I still have not figured out why mr 93 vfr 750 is'nt running up to snuff. I put this imacculate bike back together after a friend of mine took it apart over 10 years ago to powder coat the frame etc. but never got around to it. I ride it to work every day ,it runs smooth with no skips ect. But it does'nt pull nearly as strong as it should.Did I miss something when I eliminated the pollution crap A.K.A air injection system, I made plates to go over were the chrome lines bolted up.My bike also has a full Two Bros. exhaust and a dyno jet kit, whick I've played with the needle valve clip slots to no avail.The bike run smooth but has the power of a 250 Ninja. Can any of you guys stear me in the right direction?? Also does anyone know of a good V-4 mechanic in the Jax. Fl. area?? THANKS for any help !!!!! Scott McCabe

WhiteKnight · 06-22-2008, 05:49 PM

I don't know of any mech's in your area, but you might want to check the valve timing as well as make sure all vacuum leaks are plugged. Make sure the air filter is clean as well.

v4pwr · 06-22-2008, 07:19 PM

maybe the jet kit is the problem. i have heard these engines do not really take well to jetkits. i think it makes it run pretty rich but not for sure. i am still at stock carbs setup

WhiteKnight · 06-22-2008, 08:54 PM

that could be. I thought about suggesting going back to the stock carb set-up, but thought that it mught be something else. If it is easy to go back the stock carb set-up, I'd do that first. I put a D&D on my 93 and never had to re-jet at all.

motocrossscott62 · 06-23-2008, 03:03 PM

Thanks guys for your repsonses, what do you think a good start on carb setup would be @ 11 ' above S.L. and the full Two Bros complete exhaust with a K&N filter?? The vacuum lines you mentioned....are they small lines under the carbs?? I noticed that the Carb Vacuum pistons do not open all the way when I run it with the air box open?? Thanks again!!

razortongue1 · 06-23-2008, 07:53 PM

I Have Seen Wrong Order For Spark Plugs Do This, I Would Check It With The Clymer Manuel, I Purchased A Bike That Was Doing This , Firing Order Was Wrong Corrected It And The Bike Was Fixed Instantly

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06-22-2008, 10:04 AM	#1 (permalink)
motocrossscott62 Junior Member Join Date: Oct 2007 Last Online: 08-09-2008 10:23 PM Location: Northern Florida My Ride: 2007 YZ 250 2006 YZF 450 1993 VFR750F Posts: 12 Thanks: 0 Thanked 0 Times in 0 Posts	1993 VFR 750 week on power I still have not figured out why mr 93 vfr 750 is'nt running up to snuff. I put this imacculate bike back together after a friend of mine took it apart over 10 years ago to powder coat the frame etc. but never got around to it. I ride it to work every day ,it runs smooth with no skips ect. But it does'nt pull nearly as strong as it should.Did I miss something when I eliminated the pollution crap A.K.A air injection system, I made plates to go over were the chrome lines bolted up.My bike also has a full Two Bros. exhaust and a dyno jet kit, whick I've played with the needle valve clip slots to no avail.The bike run smooth but has the power of a 250 Ninja. Can any of you guys stear me in the right direction?? Also does anyone know of a good V-4 mechanic in the Jax. Fl. area?? THANKS for any help !!!!! Scott McCabe

06-22-2008, 05:49 PM	#2 (permalink)
WhiteKnight Moderator Join Date: May 2006 Last Online: 12-02-2008 07:38 AM Location: South Central Ky - Find Me! View my Photo Gallery Posts: 2,326 Thanks: 5 Thanked 19 Times in 19 Posts	I don't know of any mech's in your area, but you might want to check the valve timing as well as make sure all vacuum leaks are plugged. Make sure the air filter is clean as well. __________________ http://www.nrwhiteknight.net

06-22-2008, 08:54 PM	#4 (permalink)
WhiteKnight Moderator Join Date: May 2006 Last Online: 12-02-2008 07:38 AM Location: South Central Ky - Find Me! View my Photo Gallery Posts: 2,326 Thanks: 5 Thanked 19 Times in 19 Posts	that could be. I thought about suggesting going back to the stock carb set-up, but thought that it mught be something else. If it is easy to go back the stock carb set-up, I'd do that first. I put a D&D on my 93 and never had to re-jet at all. __________________ http://www.nrwhiteknight.net

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06-22-2008, 07:19 PM	#3 (permalink)
v4pwr Senior Member Join Date: Aug 2007 Last Online: 11-12-2008 09:21 PM Location: cleveland, ohio - Find Me! My Ride: 1997 vfr750f View my Photo Gallery Posts: 166 Thanks: 0 Thanked 0 Times in 0 Posts	maybe the jet kit is the problem. i have heard these engines do not really take well to jetkits. i think it makes it run pretty rich but not for sure. i am still at stock carbs setup

06-23-2008, 03:03 PM	#5 (permalink)
motocrossscott62 Junior Member Join Date: Oct 2007 Last Online: 08-09-2008 10:23 PM Location: Northern Florida My Ride: 2007 YZ 250 2006 YZF 450 1993 VFR750F Posts: 12 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks guys for your repsonses, what do you think a good start on carb setup would be @ 11 ' above S.L. and the full Two Bros complete exhaust with a K&N filter?? The vacuum lines you mentioned....are they small lines under the carbs?? I noticed that the Carb Vacuum pistons do not open all the way when I run it with the air box open?? Thanks again!!

06-23-2008, 07:53 PM	#6 (permalink)
razortongue1 Junior Member Join Date: Jun 2008 Last Online: 07-07-2008 06:07 PM Posts: 26 Thanks: 0 Thanked 0 Times in 0 Posts	I Have Seen Wrong Order For Spark Plugs Do This, I Would Check It With The Clymer Manuel, I Purchased A Bike That Was Doing This , Firing Order Was Wrong Corrected It And The Bike Was Fixed Instantly

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