1982 Virago 750 Rejetting for new exhaust and air filter

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MattS22
Posts: 2
Joined: Fri May 13, 2022 12:24 am
Location: Virginia
What Virago you Own: 1982 XV750J

1982 Virago 750 Rejetting for new exhaust and air filter

Post by MattS22 » Fri May 13, 2022 12:38 am

Hi all, I just picked up my first Virago a few days ago and in taking it apart I noticed it had a K&N Air filter replacement (housed within an airbox) and a set of slip-on exhaust pipes (Maybe cobras?). I just got into the carbs today and it seems the previous owner was running the stock 41 and 122 jets.

I had to rejet my Suzuki GS500 last year for a K&N filter and slip-on exhaust, and the GSTwins wiki had a chart of reccomended jet sizes given a particular set of mods. That made it really easy to simply grab the jets I needed and continue my adjustments from there.

I've been looking for similar information for a few hours but haven't turned up anything regarding rejetting the Virago 750 for these items. I'd have a hard time thinking it isn't necessary, so if anyone has any input or experience with the 750 and where I should start with jet sizes considering the increased airflow it'd be a huge help. Thanks!

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ViragoJoe
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Location: S.E. Michigan, USA
What Virago you Own: 1996 Virago Special XV1100SH

Re: 1982 Virago 750 Rejetting for new exhaust and air filter

Post by ViragoJoe » Fri May 13, 2022 11:40 am

Matt,

Edit your profile to include State and your Bike information.

California has different EPA requirements and elevations from sea level make a difference from state to state.
ViragoJoe 🇺🇸
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)


NOTE TO ALL:
:arrow: Please edit your profile with location (State/Country) & Bike Information. It will aid us in assisting you!


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ViragoJoe
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Joined: Wed May 20, 2015 10:36 am
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What Virago you Own: 1996 Virago Special XV1100SH

Re: 1982 Virago 750 Rejetting for new exhaust and air filter

Post by ViragoJoe » Fri May 13, 2022 11:58 am

MattS22 wrote:
Fri May 13, 2022 12:38 am
Hi all, I just picked up my first Virago a few days ago and in taking it apart I noticed it had a K&N Air filter replacement (housed within an airbox) and a set of slip-on exhaust pipes (Maybe cobras?). I just got into the carbs today and it seems the previous owner was running the stock 41 and 122 jets.

I had to rejet my Suzuki GS500 last year for a K&N filter and slip-on exhaust, and the GSTwins wiki had a chart of reccomended jet sizes given a particular set of mods. That made it really easy to simply grab the jets I needed and continue my adjustments from there.

I've been looking for similar information for a few hours but haven't turned up anything regarding rejetting the Virago 750 for these items. I'd have a hard time thinking it isn't necessary, so if anyone has any input or experience with the 750 and where I should start with jet sizes considering the increased airflow it'd be a huge help. Thanks!
=======================

Matt,

Anytime the intake and/or exhaust are modified there are always consequences, for you are changing how the engine breathes!

The problem with drag pipes on a street bike

https://www.youtube.com/watch?v=ezpM5rGpIx8

There really isn't a chart that I am aware of that gives that information like it does for your other 2 wheel toys.
Suggest that you contact K&N and Cobra for there Jetting recommendations.

Pages from the Clymer's Manual with page numbers.

Click Images to Enlarge:
CARBURETORS REJETTING CLYMERS PG 131.png

Your Virago designation for 1982 is XV750"J
" The reason Model designations are important for Virago's to obtain the correct specifications for a specific model year! 1988 XV750"U" is different and they're Mikuni Carbs..
CARBURETOR SPECS CLYMERS PG 143.png

EDITED 5/14/2022: Dealer Information added below:

Now here's a dilemma:

Yamaha Dealer parts schematic for 1982 XV750J shows the following, so who's right, (Clymer or Dealer) #24 Main Jet?!
Since you pulled 122 main jets from your carburetors. I'm leaning towards Dealer being right! Well, So much for documentation. Makes it difficult for one can't believe everything one reads and must research everything. Like we have found here.

Click Images to Enlarge:
CARBURETOR 1982 XV750J.png
CARBURETOR MAIN JET 1982 XV750J.png

Consult with K&N and Cobra for there Jetting recommendations.

One reason I left my bike totally stock. Too much disinformation out there regarding modifications and I'm getting to old to sift out all the pepper from the fly poop.
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ViragoJoe 🇺🇸
1996 XV1100SH Virago Special
"Never ride faster than your Guardian Angel can fly!!"
;)


NOTE TO ALL:
:arrow: Please edit your profile with location (State/Country) & Bike Information. It will aid us in assisting you!


All topics are archived by vehicle families for easy perusing and to find answers.

Also: If this website was helpful, please consider donating to help keep this site here for yourself and future Virago owners.

MattS22
Posts: 2
Joined: Fri May 13, 2022 12:24 am
Location: Virginia
What Virago you Own: 1982 XV750J

Re: 1982 Virago 750 Rejetting for new exhaust and air filter

Post by MattS22 » Sat May 14, 2022 1:33 pm

Thanks for the responses, normally I wouldn’t mess with intake and exhaust without having a plan for the carbs but it seems one of the previous owners was more eager to modify the bike. I’ll try contacting k&n and cobra to see if I can track down some info on jet sizing and post what I find in case anyone has a similar issue in the future.

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