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-   -   Running Rough after Mods (https://www.superhawkforum.com/forums/general-discussion-30/running-rough-after-mods-17483/)

Denverhawk Feb 9, 2009 11:15 AM

Running Rough after Mods
 
Hey all,
People were so helpful with my last question, I'll ask another! I recently installed de-baffled OEM pipes, a K&N air filter, and PAIR block off plates (also plugged hole in the airbox that fed PAIR and plugged vacuum tube that actuated the solenoid that controlled PAIR). I then put the bike back together but now it barley runs. Background; I posted earlier and forum members helped me diagnose that I had misplaced the vacuum tube to fuel petcock causing complete non-starting (thanks guys!). Now the vacuum tube is placed correctly and the bike starts right up but will only run with the choke all the way open and only to 1/2 throttle. With the above mentioned mods (no other relevant ones that I can think of, everything is cosmetic) is this behavior to be expected? I expected it to run rougher but thought I'd still be able to ride. I own a K&N Stage 1 Jet Kit that I'm shopping around to have installed and if this behavior is normal for the mods I've done I'll trust that the Jet Kit will solve the problem. I just want to make sure before I pay someone to install the jets that other then fuel/air mixture, the bike is mechanically sound. OK, my one disclaimer, I have not checked the spark plugs yet. I know I should, I'm just waiting to pick up new plugs and plug wrench (my shop's not open on Mon.) since I figured while I checked them I'd just replace them on principle. Any thoughts on this would be much appreciated. I was under the impression that the mods I've made would increase air meaning the engine would run lean, does it then follow that opening the choke increases fuel to the mix which is why she only runs with the choke wide open? Prior to this I thought the choke added fuel, now I'm confused! My Haynes manuel does not talk about carb adjustment much except to detail a full removal/installation and disassembly/cleaning/inspection but says under the "Idle fuel/air mixture adjustment- General information", "The pilot screws are set to their correct position by the manufacturer and should not be adjusted or removed unless it is necessary to do so during a carburetor overhaul". I am a shade tree mechanic and do not feel quite ready to tackle a complete carb rebuild, hence my willingness to pay someone to install my jet kit. Thanks in advance!
P.S. I'm in Denver but had the carbs adjusted in '05 when I puchaced the bike used, and she did run prior to my mods.

Little_Horse Feb 9, 2009 11:34 AM

sounds like something wasn't put back together right. Those mods shouldn't make the bike go from running to not running as extreme as you describe. Check that everything is connected from all the air lines to spark plugs. For starters, make sure your petcock is back in the on position as well. Keep us posted we will help :D.

8541Hawk Feb 9, 2009 12:02 PM

Did you have the tank off? If so make sure you hooked up the vacuum line to the petcock in the right place. It goes to the nipple on the side of the petcock, not the bottom.

Denverhawk Feb 11, 2009 08:29 AM

Sorry for the delay, life got in the way! I'll be able to triple check under the tank in a day or two and have plugs and a Honda OEM Plug wrench coming next week. I'll keep posting though as soon as I have wrenched some more. Thanks for your thoughts Cornandp, nice no know that the symptoms are unusual at least.

BIG DAVE 03 Feb 15, 2009 04:04 PM

Had the same issue today. Found that I did not turn the petcock back to the correct position. All seems to be well now.

Denverhawk Feb 18, 2009 08:09 AM

Well, I tore down the bike (wanted to adjust freeplay in throttle cable) and upon re-assembly the bike ran fine. petcock, vacuum tube, fuel line, I don't know but probably something similar and simple. Thanks for the help. To those who care the new pipes (de-baffled OEM) sound great!

CentralCoaster Feb 18, 2009 03:37 PM

It was probably a vacuum issue. The choke helped it run because this reduces airflow to the engine, which got you closer to stoich.

reaper Feb 20, 2009 06:26 AM

Do yourself a favor and download the FSM for the Superhawk because the Haynes manual may not cover everything there is to know about the bike.

As far as the jet kit goes, do the install yourself. It is not hard does not require special tools, although make sure your kit has the wrench that will allow you to adjust the a/f screw. If not there is a thread how to make one using a brake line. By doing it yourself serves two purposes, first - your not paying someone else to do it and second - you learn something new to do to the bike.

There are plenty of members, including myself, that have done this mod and are more than glad to help.

Good luck.

kai ju Feb 20, 2009 07:24 AM


Originally Posted by CentralCoaster (Post 201527)
It was probably a vacuum issue. The choke helped it run because this reduces airflow to the engine, which got you closer to stoich.

The choke is actually an enrichener circuit.
It does not "choke" the flow of air but adds fuel.
Just to clarify.

Kai Ju


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