Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Bullet Electra & AVL => Topic started by: mypvtidho on November 16, 2012, 12:48:27 am

Title: Part throttle bog. Adjustment?
Post by: mypvtidho on November 16, 2012, 12:48:27 am
2006 Bullet 500. 8,000 miles. Loud cone style exhaust and re-jetted by last owner. When in gear and underway, from low rpms to just accellerating, it has a bad stumble or bog. Runs strong once the rpms climb to halfway or so and beyond, but does not want to cruise at low rpms. I am assuming it is lean on the bottom end. Wrong or right, is there something to adjust on the carb for this?
Title: Re: Part throttle bog. Adjustment?
Post by: DanB on November 16, 2012, 01:48:37 am
What kind of carb do you have? AVLs have stock Ucal CV carb. If that's what you have, take a look in the gallery under my name. I uploaded a number of data sheets on this carb that may help you.
Title: Re: Part throttle bog. Adjustment?
Post by: mypvtidho on November 16, 2012, 04:36:33 pm
Sounds good, but I cannot figure out how to look up anything in your, or any gallery.
I also have not figured out how to search efficiently and thus far get too much information about nothing. A horrible handicap, but one I have not learned to overcome.
I still have a cool new bike with a poorly adjusted carb.
Title: Re: Part throttle bog. Adjustment?
Post by: boggy on November 16, 2012, 06:45:58 pm
Tell us what carb you have so we more info.  It sounds like you have an aftermarket exhaust?  Do you know if the owner swapped carbs too or just re-jetted the stock one?  If you are not sure, upload a picture for us.  If you know what carb it is, you can search for it here and probably find lots of info on how people tune them.

I had a rich bog on my AVL.  Just as you described, it was fine down low and bogged at about half-throttle.  I run a PWK flat-slide carb, which is not standard on a Bullet.  I had to go much leaner on my main jet. I knew this because I performed a plug chop.  My spark plug was very sooty indicating it was way rich.  I also had to change the position of my needle.

Provide some more info and we'll see what we can sort out.
Title: Re: Part throttle bog. Adjustment?
Post by: DanB on November 16, 2012, 11:07:36 pm
Sounds good, but I cannot figure out how to look up anything in your, or any gallery.
I also have not figured out how to search efficiently and thus far get too much information about nothing. A horrible handicap, but one I have not learned to overcome.
I still have a cool new bike with a poorly adjusted carb.

Follow this link to search the gallery. http://www.enfieldmotorcycles.com/forum/index.php?action=gallery;sa=search. Then, type UCAL in the 'search for ' bar. That should bring up the cv carb info.
Title: Re: Part throttle bog. Adjustment?
Post by: mypvtidho on November 17, 2012, 05:20:51 pm
Not UCAL. I'm thinking mine is classic cast iron, not AVL. Aside from admiring R.E. Bullet looks for years, total R.E. newb as of last week. I believe Carb is the stock one. Thumb screw Idle adjustment on left side (screw is parallel to ground, not perpendicular like UCAL) and embedded adjustment screw on right side of carb.
Title: Re: Part throttle bog. Adjustment?
Post by: mypvtidho on November 17, 2012, 05:22:09 pm
Was able to get pic of UCAL carb, but no others from search.
Title: Re: Part throttle bog. Adjustment?
Post by: boggy on November 17, 2012, 08:08:00 pm
Give us a pic of the engine + carb so we can help you out. Otherwise, we are all shooting in the dark.
Title: Re: Part throttle bog. Adjustment?
Post by: ace.cafe on November 17, 2012, 10:48:37 pm
2006 could be either AVL or Iron Barrel, but the carb you describe is what's on an Iron Barrel engine.
You have the Mikarb 28mm carb.
If it's stumbling at low throttle opening, then you can try screwing-in the embedded angled screw about a half-turn, and see if that helps.
If not, you may need a richer needle jet or a richer throttle slide, depending on exactly what throttle opening this bog is happening at.

It would help if we knew what jets are in there now, and what elevation above sea level you are at, and what temperatures you are having, and what air filter you have.

Regarding cruising at low rpms, the bike isn't intended to cruise at low rpms. It is intended to cruise in the middle rpms.

Are you in India?
Title: Re: Part throttle bog. Adjustment?
Post by: mypvtidho on November 19, 2012, 05:42:43 pm
Back at home with the bike. Mikcarb. Just like Micuni diagram. Easy to disassemble to adjust needle position and adjust idle circuit after a few goes. Had it apart 3 times yesterday. Could not get it quite right. This morning discovered why. Vaccuum plug blew off vaccuum pipe between carb and cylinder from backfire during kick start. Thanks for assistance.
Title: Re: Part throttle bog. Adjustment?
Post by: LarsBloodbeard on November 19, 2012, 11:07:18 pm
Looks like the VM28 to me...  Should be stamped on the body somewhere too.