[rexsk8er]

Ok, so about a year ago I bought a 2006 Royal Enfield Bullet 500cc Military.

And wow, what a eye catcher. The bike came in the shop I work at to have the starter fixed. It had set a while and the owner couldnt get it to start. Hes the kind of guy who buys a 5-8 bikes a year rides a few months and sells them. So when he got the quote to pull the whole primary and starter drive system, he approached me to sell the bike. I had couple hundred stashed away, not the $1000 he wanted. (hell of a deal less than 3000 miles and fairly clean) So I offered the cash I had an to make payments. He accepted! SO after about 8 weeks of top romin noodles and pb and j sandwiches i had a new bike. After fixing a broken rear spoke, adjusting the breaks, checking points gap, cleaned the carb, oil change, added a fuel filter and replacing a few clutch cables I have the bike in tip top shape for the road. I ended up useing a Honda gold wing cable to alleviate the chaffing on the inner part of the lever that kept causing failure.

The bike seemingly has two mods. One being a cone style filter, with the PCV system routed through a hose ending at the chain. Secondly the muffler is either de-baffled or a short euro system. The bike definatly sounds louder than any stock single I've heard. Id say 80db.

When I first got the bike it was a little hard to start, but after getting it running and cleaning the carb it kicks over 2nd or 3rd try. No choke needed which is odd IMO.

Now the problem

The bike idles great, and goes down the road decent. Good fuel economy and no problems, EXCEPT when at a low throttle cruse. If you wrap the throttle, it has a hiccup or a slight hesitation than fires to life and accelerates hard. While in neutral if the throttle is opened to 100% off idle, it will bog and totally die. But, if you are just a hair over tickover speed, say 10% over idle, the engine accelerates beautifully.

Sounds to me like a lean condition. So, I opened the carb back up, and I installed a 125 jet. The jet that was in the carb when i got it was a 120. So, after starting the bike and warming up, following the standard method to adjust the low speed air screw and idle, the bike still runs the same. Than I thought, maybe ill check the needle. It was set one slot above the bottom. So, i figure maybe try putting the needle towards the middle, 3rd up from bottom and the 115 jet, with smaller idle jet at 25 (had 27.5) Well, this created an obvious bog at low speed cruse, with the same issue in neutral. Figuring that since its worse, and that after restricting the air flow with my hand over the carb it reved well, I put the biggest Jet i have in the bike(130), than dropped the needle clip to the bottom, installed the bigger idle jet. Now the bike starts the same, and of course I tuned the low spead accordingly with each jet change. But it still has the problem bogging in neutral, and a light hesitation on fully open throttle at low rpms.

My biggest problem is I have no idea what the stock jet size is. I have  the owner/service manual but it doesnt give stock specs for carb jetting.  I cant find info in the internet either. It has the Mikcarb vm28.

I think i just need to tune it richer. Tommorow im going to drive the bike a bit more than normal, and check my plug with the current tune. The plug originally showed signs of a lean mixture but not bad. The other odd thing is that when I pull the choke it dies. It doesnt matter if its cold or warm or anything. The bike will run on choke, if you increase the idle but it doesnt seem to run better and is slightly restricted in the top end.


Anyway I tend to go on and on, but hopefully someone can at least chime in about the stock jet sizes.


Thanks, Sean

[C.C.]

Stock jets are 115 main, 25 pilot with clip on center slot with idle screw 1.25 turns out. This is way to lean even with stock exhaust. I run a 120 main, 27.5 pilot and the clip on the bottom slot with the idle screw .75 turns out. My bike has a stock exhaust and air filter. Make sure the float is set at 28 mm.

CC

[rexsk8er]

Ok, awesome so I'm on the right track. Thanks for the information. I might try 135, and a 30 pilot. But only after I verify the ignition timing. Considering the points gap is perfect, .015" IIRC and the bike has a little under 3000 miles im sure its in time. But Id rather verify for peace of mind.

I really like the peppy handling of this bike. I'm planning deleting the E/S and doing some motor work to allow sustained speeds over 50mph. (cams 535 an maybe a big head conv or pnp oil cooler ect) I live by the interstate and its better than the crappy surface roads...

[greekxj]

Hey, just an FYI. If you feel like you are lean in the middle the carb could need a bigger needle jet. They are not cheap but can be necessary in some cases. My 07 was a finicky bugger and it took me a while to get it pretty good(still  not perfect), but it was kinda tough with the stock carb and a cone filter with an open Goldie pipe. Not saying that's what ya need but if you start doing plug chops and its lean in the middle that's a possibility.

[Moto Fugazzi]

Sounds like the same problems I had on a different bike I had last year with pod filters. I could never get it to run perfect, but did manage to get it running really good. I think it's the nature of pod filters when you remove the airbox. I even noticed a huge difference with strong crosswinds-the bike seemed to run much leaner.

You may need the P2 needle jet from www.nfieldgear.com That should take care of your hiccup problem. Ideally, I would try to get your hands on the ACE air canister-it looks as good as it performs. I just put one on my bike and re-jetted with a 27.5 pilot and a 127.5 main, and the needle raised all the way up (bottom notch). It looks like I need to make everything a little richer at this point.

I also cannot use the "choke" on my bike. Even in 30f temps, the bike will die if I turn the choke on. It does start of with 1 or 2 kicks without the choke, and it just takes a little longer to warm up.

Hope this info helps.
Ken

[baird4444]

"I also cannot use the "choke" on my bike. Even in 30f temps, the bike will die if I turn the choke on. It does start of with 1 or 2 kicks without the choke, and it just takes a little longer to warm up."

   ok, just to clarify....   it only runs with the "choke" lever
                         up or down???

                            - Mike

[rexsk8er]

Awesome. Thanks for the help.

I kind of thought along the same lines with Moto Fugazzi with the pod filter just having to little restriction, along with being much shorter in length shifting the torque curve a little higher creating a lean spot in midrange.

My bike runs with it up or down, if i push the choke lever down (plunger up) than the bike dies, unless i keep a hand on the throttle. Runs good with the lever up (plunger down)

[rexsk8er]

[baird4444]

just had to ask. you wouldn't believe the number
of people that will have the lever down thinking that the
"choke" is OFF. When this is done it completely screws the
theory and the fix.

[Lwt Big Cheese]

Nice looking bike, there.

[ace.cafe]

just had to ask. you wouldn't believe the number
of people that will have the lever down thinking that the
"choke" is OFF. When this is done it completely screws the
theory and the fix.

Baird is SO right about this.
Even I got this wrong when I got my first Bulllet.

Anyway, about the OP's question, I think it needs a richer needle jet, like a P2 which was suggested above.
And it might need a 127.5 or even 130 pilot jet.
The stuff about throttle response off idle and small throttle positions does not indicate main jet issues to me. Much more like pilot jet or needle jet issues.

[Moto Fugazzi]

"I also cannot use the "choke" on my bike. Even in 30f temps, the bike will die if I turn the choke on. It does start of with 1 or 2 kicks without the choke, and it just takes a little longer to warm up."

   ok, just to clarify....   it only runs with the "choke" lever
                         up or down???

                            - Mike

Choke lever up on my bike. I haven't tried it with the choke lever down while giving it some throttle.
Ken