Possible Valve Problem?

[YellowJacket!]

I may have asked this in the past but I thought I'd bring it up today after noticing something peculiar while YJ was running today.

After dusting off the cobwebs last week I fired YJ up and thanks to the fully charged AGM, she started right up with very little protest.  She ran ok, just a little rough but thats expected after being not run for quite a while.  After she warmed up I took her for a ride.

Well, today was 70 degrees and I decided to take her out again to clear my mind.  Again, she started right up but, while she was idling, she was running a little rough on her rear cylinder.  Since I have the MAC's I can feel the exhaust separately between the front and rear.  The front was giving my fingers a very good and regular "snap".  However, the rear was a bit more irregular and almost felt like it was sucking and pushing.  It was more like a pop-suck than the snap from the front cyl.  This was after letting her warm up for about 15 mins.

She rides fine, does not stall or bog, so I'm a bit puzzled.  Its one of those things that now that I know about it, its gonna nag me.  Y'all think its something I should dig deeper into or just keep an eye on?

She now has about 12k miles on her.

David

[Kenny]

     :police: When was your last Valve adjustment ?  I would do a Compression Check, that will tell you what's happening in th cylinders.
       Riding weather in mid Ontario. WOW ! ;) ;)
                     Cheers   Ken S.

[Re-Vision]

Sell that junker, how much you want for it? I'll put a nice yellow full fairing on it and make it look good.  haha    BDC

[YellowJacket!]

     :police: When was your last Valve adjustment ?  I would do a Compression Check, that will tell you what's happening in th cylinders.
       Riding weather in mid Ontario. WOW ! ;) ;)
                     Cheers   Ken S.

Hi Kenny,

No valve adjustment yet.  Just hit around 12,000 miles.  I think I still have a compression test kit.  If not, I'm sure Lucky does.

@re-vision.  How about you just give me that yellow full fairing and we can both be happy.  :-)

David

[QBS]

Sounds like a partially plugged idle jet.  After all, it had been sitting for awhile.  And you know how much they hate sitting.  Hopefully, you drained the float bowls before the long sit.

[Tiger]

 :) Dave, change the rear spark plug...or at least remove, clean and regap it...reinstall and try again ;)

                   8) .......TIGER....... 8)

[YellowJacket!]

@QBS, Yep, drained the bowls and had run some seafoam through the system before putting her up.  Also started her up a couple times to run fuel through with the cleaner in the tank then drained the bowls.

Heres a bit more:  Starts with enricher on and warms up after a few mins.  Turn enricher off and idle is steady - but above problem with rear cyl.  Turn enricher back on and idles like crap so my assumption is that that is correct behavior once it is warmed up.

@ tiger,  I'll give that a try.  I know I have GOOD plug wires...I got them from you (shameless plug for tigers awesome custom plug wires).  Plugs are only one, maybe two seasons but I will definitely check them.  I may swap out the coil too as I have a spare.

David

[Rikugun]

Most people would be thrilled their Vision started easily after sitting but you want even exhaust pulses too!!?? Sheesh.  :D   :D

I hope one of the easier fixes cures it but with 12k showing I'd encourage a valve check regardless before the season begins in earnest. I think the manual calls for initial at 3000 miles then every 5k thereafter. Have they ever been checked? I'd suggest trying a carb sync but would rather see you do that after a valve check.  ;D

If available, a leak down test on a warm engine may be more revealing than a compression test.  Good luck.

[Lucky]

Dave, I have both a compression tester and a home made leakdown tester  that i haven't used yet, but i'd bet it's carbs.  both Kittys and specter's bikes are impossibly hard to start, & i'm going to begin with the carbs..

I rode Cafe to work today for the first time since putting the Macs on,  gave that BBQ black paint a good cooking, lol.  they sound like Macs, but i sort of wish this bike had that 'whiney sportbike' sound..

[Kenny]

  Dave,
    If you still have the Compression Tool Kit  do a quick check, it'll give you a health check & keep the numbers for future reference.Besides it's a lot easier/ faster than pulling the Carbs & disassembling them.
               ;) Cheers Ken S.

[Coil Coyle]

I may have asked this in the past but I thought I'd bring it up today after noticing something peculiar while YJ was running today.

After dusting off the cobwebs last week I fired YJ up and thanks to the fully charged AGM, she started right up with very little protest.  She ran ok, just a little rough but thats expected after being not run for quite a while.  After she warmed up I took her for a ride.

Well, today was 70 degrees and I decided to take her out again to clear my mind.  Again, she started right up but, while she was idling, she was running a little rough on her rear cylinder.  Since I have the MAC's I can feel the exhaust separately between the front and rear.  The front was giving my fingers a very good and regular "snap".  However, the rear was a bit more irregular and almost felt like it was sucking and pushing.  It was more like a pop-suck than the snap from the front cyl.  This was after letting her warm up for about 15 mins.

She rides fine, does not stall or bog, so I'm a bit puzzled.  Its one of those things that now that I know about it, its gonna nag me.  Y'all think its something I should dig deeper into or just keep an eye on?

She now has about 12k miles on her.

David

Dave,
A Vision gives you about 3000 miles of warning before you must check your valves.
:D
Dave,
It's time to check your valves.
:D
And; keep eating the Vitamin D.
;D

If you need shims I'll mail swap with you. Let me know and I'll front the shims USPS.

$0.02
;)
Coil