Bike running lean
 

I installed a Dyno Jet jet kit this winter on my stock motor. From what Dyno Jet recommends I bumped it up 5 on both cylinders (185 front, 190 rear) and raised the needle one notch. The bike acts lean and runs much better with 1/3 choke. It ran much better with the stock jetting which was (178/190) and the needle looks identical and sits at least one notch higher than stock. My pilot screw is at 2 1/4 out. I'm thinking I should back the pilot out to 2 3/4 but I have to pull the carbs so I want to get it right this time.

I hear dyno jet jet sizes run a bit smaller than stockers. I do live in Anchorage, AK where it's about 101 ft above sea level and the air is a bit cooler than the continental US. Any help is greatly appreciated!

Don't mess with your pilots. I think your problem is either main jet size or needle height. What cans are you running?

Stock. The bike is completely stock.

Hmm, interesting. Any reason why you jetted a completely stock bike? They run pretty fuggin good from the factory.

Did you store the bike with Stabil in the gas? Did you run the bike with Stabil-ized gas for a little while before you stored it?

The reason I ask is because this sounds to me like a clogged jet problem.

Last question, under what conditions does the bike run crappy? Load? RPM?

I jetted it because thats what everyone recommends but I'm seriously thinking about reinstalling the stockers. The tank was just removed and drained. 500 miles of fresh gas gone through.
If you pull the throttle the engine hesitates and then takes off and the idle is a little harsh. After it takes off it runs great. Not as crisp as before but it accelerates well.

how long has it been since you changed the airfilter? I just fixed my wife's bike with the same symptoms you were describing. new airfilter fixed it right up.

I would have left the carbs alone if i was running stock cans. If you can, get yourself a set of cans and use the correct jets for them, on my old bike, dynojet supplied me with the correct kit for my specific cans and it ran like a dream.

The mods to the slide needle made my bike bog at low RPM/cruise and some idle, try pulling the needles one notch back.

The air cleaner is stock and new. A plugged air cleaner would actually make it run rich though.

You mean drilling the slide? Thats a thought. I still have the stock springs and an extra set of undrilled slides. Messing with the needle isn't so bad as I don't have to pull the carbs. Thanks.

If I may, based on the rough idle and hesitation on giving it throttle, I would tend to think you may be dealing with a vacuum leak. Are you sure that all of the hoses,... were hooked back up properly?

Hope this helps

I had this flat spot, but for taking the caps out I had to pull the carbs out of their seats, but left the coolant hoses hooked up, to get to the front slide. Took me 1 hour with a hand drill and a long bit, I'm getting better at yanking everything off and on.
Have a couple of cold ones to keep you going, it makes a painful job not so painful :D

Thats good advice but I was pretty paranoid about seating the carbs as they have been an issue in the past. It would explain both the lean condition and hesitation though. I'm going to double check when I get home. Thanks!

A six pack should do it. If I knew what the was going on and how to fix it I'd have no problem pulling them, it's the pulling them more than once I'm afraid of.

Over and above the carbs themselves, check all the lines too.

Good luck :)

I got this info from my friend and followed this setup. I went with a total of 40 thou. counting The stock shim. It ran perfect with the stock pipes. I desmogged it at the same time. It was a 2005 model. Before I shimmed it it ran like crap. (lean) By the way I miss my Superhawk but love this unit even better. :)


I would adjust the pilot screws properly (Honda Idle drop method) and possibly try shimming the needles with a .040" shim (3mm flat washers). Unless you make some major changes in air flow, the stock jet sizes are fine. A dynojet jet kit will help but will kill your gas mileage (most likely from whacking the throttle wide open all the time ) You may find that adjusting the pilot fuel screws is impossible because they're tamper-proofed to the general public. Depends on the year. Some of them use a slotted screw head and the tamper ones have a "D" shape head. You can see them in front of the float bowls on either the side or bottom (I think it's the bottom on that model.) Let me know the year and I will look at the next one that comes by if you can't find it. Start with the screws out about 3.5 turns from lightly seated.

Whoa! No, not 3.5 turns. That's wayyyy too much. 2 turns out max with stock cans and filter. I personally think your idle jets are clogged from the winter. Get some good carb cleaner, pull the carbs and idle jets (one at a time because they are different) and clean the small passages with a small copper wire.

+1 on what beesfan said. I'd revert back to stock jetting unless you get some slip-ons.

Lot of you guys run the dynojet kit. What would you run in a stock bike other than the manifold flaps smoothed out. I'm at 100ft above sea level in anchorage, ak so the cool air is a bit dense.

Main jet, needle clip position, mix screw.

I'm almost ready to plug the slide holes and run stock jetting with 40 thou shims. Anyone want to buy a lightly used dj 1185 kit?

Take it up with Dan. He said the Honda Idle drop method anyway. So you would not be anywhere near 3.5 turns out when set right.

http://www.motordoctor.net/html/message_board.html

Honda recommends 175/178 and 2 3/4 out at 5000-ft, or 173/175 and 2 1/4 out for 6000+ft. Because I'm at sea level I'm going to set it at 178/180 and 3 turns out. I'm going to start the needle one notch richer than stock. dj springs with slides drilled. The only thing I'm worried about is dyno jet jets sometimes run small for their size and the 178 will be a stocker and obviously I want the rear to be a true 180 if the front is 178. Hopefully it yields good results because I only want to pull them once.
As far as the pilot screw goes I don't understand why you guys like it so lean. With stock jets my bike ran perfect and wouldn't foul plugs no matter how long it idled. Its not like the main jet is contributing much if any to the idle circuit so stock is probably best.

The carbs, lines, and tank were removed and completely cleaned. I'm not talking a newbie spray down but disassembly checking each passage for flow. I'm a pretty decent mechanic I'm just frustrated because the baseline advice I got was very bad. Most people think bigger jets mean more hp and I should have used my head. I think my idle circuit is lean and my high speed circuit is rich thats why my midrange transition is the only strong part of my powerband. I should have gone with dyno jet's recommendations or just shimmed my needles.

get rid of the right can and slip a D&D so you get a frankenexhaust like mine, it loves bigger jets, don't attempt to tune without changing air filter.

I let the bike warm up then sprayed wd-40 all around the carb boots. No fluctuation in rpms so the carbs are seated.

The bike isn't going to run lean at 2 turns out. It's probably going to run "just right". You can try it or not, it's up to you. I suggest checking the position of the pilots first before you make any adjustments. It might just be they're 1.5 turns out from the factory, regardless of what the service manual says. If you decide to go with 3 turns out then let the bike idle for about 5 minutes and check your plugs for black soot.

Oh, and I'll bet you $20 that you're the only one with a jet kit and bone stock exhaust on the forum. It's going to be hard to find someone else's baseline settings if there are none out there. You're moving into unknown territory at this point. Good luck.

Where did you get those Honda recommended values for mixture screws?

Dan who?

The factory manual. As far as the pilot settings I set them myself. No rookie mistakes here just needed tuning advice.

well, we all know ive pulled my carbs out of my boots about , ehhhh, 75 times. so many times to adjust everything(i think its fun) , that i bought new rubber boots cus one was torn!

my 2 cents if your bone stock,

air mix screws: 2 1/4 turns out.
needle jet: 3rd clip setting(middle)
pilot(slow jets) : leave them stock at 45 trust me)
main jets: (175 front, 180 rear)

that would be running slightly more rich than stock.

i just went from 48 pilots to 45s ,
185/190 to 180/185
2.5 turns out
and man what a difference! i was running rich as hell and i have k&n, and MIG high mounts(open as hell) .no more popping up high in rpms on decel, flat idle, etc. only thing i dropped down were mains and pilot back to 45s .

this should be a good setting in my opionion .
and make sure you dont tighten the boots too tight around the carb throats, doing so will make the rubber above the clamps 'bellow out'(vaccuum leak)

The factory manual does not give recommended final settings. They give recommended initial settings prior to the idle drop test, and they give one for high altitude (minus 1/2 turn).

It gives 2 3/4 as an initial opening under 5000ft and then you use the idle drop method. My never touched stocker were set at 2 3/4 though. I'm going to make myself a special tool and use the idle drop method.

Welp I pulled the carbs and things are a bit more clear. I bought a use set of carbs from ebay and when they came I didn't separate them so I wouldn't have to sync them. I should have because they were way off. I'm kicking myself for not looking more closely. The idle is smooth now. I installed 178/180 jets and it runs pretty good. I'm going to fabricate a pilot screw tool so I can fine tune the pilot but other than that I'm doing pretty well.

Thanks for all the help guys!