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87 virago

I'm working on my virago 1100 and I recently put a single manifold system on it got it in properly sealed and adjusted my fuel and air mixture and am still getting tons of back fire upon deceleration I was wondering if this was due to the air induction system and if so what the best way to remove this system is



1: MCV/AIS removal Author: draper84, Post Posted: Sat Mar 22, 2008 3:10 am

This post is meant to be a step by step on how to remove the mcv/ais on the 1985 xv1000. i hope to write it so everyone can understand

1. Remove the bolt under the left side bug eye (shiny silver thing where your left knee would be if you were riding the bike)

2. remove the silver cover by pulling out and up.

3. remove the hex bolts holding the mcv/ais plate on the motorcycle. (one on the top right and one on the top left)

4. At this time you will be able to access the clamps and vacuum lines that go into the mcv/ais unit. begin to remove those clamps.

5. take all of the vacuum lines off of the mcv/ais unit. at this time it should look similar to this [img=left]Photobucket[/img]

6. take the small vacuum hose coming from the front of the bike apart from the "T" this small hose goes to the pressure sensor that controls the timing of the motorcycle. [img=left]Photobucket[/img]

7. at this time we can take the vacuum hoses off of the carburetors remove the two hoses that attach to the front carb boot and plug the larger connection with a vacuum plug. (1) [img=left]Photobucket[/img]
(2) [img=left]Photobucket[/img]

8. Now remove the coil cover under the forks of the motorcycle and you can see where the small vacuum hose runs. i re-routed this through the opposite side (Left if you are looking at it from the front of the bike) to gain a little more length.

9. plug the small vacuum hose onto the small connection on the front carb boot. this will let you still have timing on your bike. kind of important

10. next we can remove the clamps that hold the 1/2" chrome lines to the engine. these after the clamps are loosened should come right off. [img]Photobucket[/img]

11. now for the fun part. to cap these connections. i used a smooth rivet type of thing that was a snug fit into the port, tapped it in with a rubber mallet and put a hose clamp back on ( also have read of people just connecting these lines with the black hose between them)

12. checklist.
a. (most important) small vacuum hose from pressure sensor connected to small connection on front carb boot
b. large vacuum port on front carb boot plugged
c. two 1/2" exhaust ports plugged or connected
d. unused vacuum lines removed from between carbs
e. backfire gone Laughing Laughing

Great Write up Edwin - Should do the trick nicely ... I hope that Shiny can get it sorted on his Virago ... Fairly straight forward job and Stops the Backfiring ... Happy Days ... Heyyy !!!
Ride Safe ....

Thank you for the info it helped no more backfire the bike it's running better than ever

Hi Shiny - Hey that is Good News - now you can get out there in the Spring/Summer and get some miles under your belt a much happier rider and with a much happier bike ... Definitely a Win/Win situation for you - A Big Shout out to you Edwin for all the Help Offered ...
Cheers to you's Both ....
Ride Safe ...

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