It's time to start a winter Project. The Red Bike

I rode for 20 miles of combined city country riding today. The forks are a joy compared to the tracker. An early faux pas involving erratic running, missing, dieing and a long push home were resolved with selecting the "On" position of the fuel petcock. While the bike settled into a 1200 rpm idle easily, as the bike warmed up it was 1600, then 1800. The Commando muffs sound pretty good with out being tiring, my tracker is entertaining but tiring. Engine response seems pretty good but there is a burbling/stumble at 4300 rpm. I need to ride these VMs a little more before I do jetting changes but with the stumble at 4200 rpm my thought is a step richer on mains.
 
Jim said:
How is it at WOT?
If it feels good there, try going up one step on the needle and see if it cleans up.
Click to expand...
Thanks Jim, I am so new at this I forget the other variables. I need a few more rides to pinpoint the problem and a needle adjust is easy with these VMs it seems. I also was not on any road where I could go WOT through 4200rpm for any length of time.
Plug check gave me medium light chocolate on the insulator which I think means the pilot jets are pretty close. I gave each air jet 1/2 turn in because the idle was slow to lower and the motor seemed to respond to that. My earlier foolishness with a closed petcock led to a kick starting mishap aggrevating a right knee with no meniscus so I didn't hover over the bike for long, seeking refuge in Tylenol and whiskey.
 
I find it is popping (muffler sppffft) irregularly at steady state 35 -45 (very small amount of throttle) mph 4th and 5th. Full throttle seems to pull but with a helmet on I cant really hear the exhaust. Plugs are light chocolate to white. Pipes getting a golden hue.
 
Iirc, there's a pdf in Tech on setting up the VM carbs for the XS. Have you looked at that?
 
I think some of my issues are related to the PO using slack adjusters to set idle speed:) I went back to VM 101 to get a base line today. Still studying and undoing what was done before....and kicking myself in the ass for not checking these things...:)
 
Last edited:
Jim said:
VM guide
Click to expand...
Thanks Jim. I have idle now (after eliminating to PO set-up and syncing carbs) and the low and mid range are pretty good. I have a barking/miss around 5k rpm and I will see if lifting the needle helps that or eliminates that. The all around driveability is very nice right now. I added the neutral safety switch jumper per @5twins earlier post after getting stuck dead in traffic a couple of times and having to find neutral. I should have known better.
 
Kevin Werner said:
Thanks Jim. I have idle now (after eliminating to PO set-up and syncing carbs) and the low and mid range are pretty good. I have a barking/miss around 5k rpm and I will see if lifting the needle helps that or eliminates that. The all around driveability is very nice right now.
Click to expand...
If you don't already have it, here's a breakdown of jetting zones for the VM carbs.


1689105852528.png
 
Adding more miles today the bike seems alive. I have narrow bars on my tracker and that and the forward lean stance makes it feel cumbersome compared to the red bike. I am reluctant to change the shocks (Koni) but the kickstand is worrisome short. Do I just weld in a 2" extension on the kickstand or find shorter shocks?
 
Just reread... 2inches? That's a lot. Got any 1/4" plywood laying around? Cut little squares and stack em till you get the right amount of lean, then just count the stack...
 

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