Honda VTX 1300 / VTX 1800 Motorcycles Forum banner

Carb damage? Won't take quick throttle

4912 Views 15 Replies 3 Participants Last post by  Noisy Neighbor
Being the genius auto mechanic that I am I tried something very common place on a automobile carburetor when there are running issues. I thought I may have a jet blockage so I tried to choke the carb at wide open throttle. Now the bike won't take anything but a very slow roll on the throttle. If I try to rev it, it just falls on its face. Running WAY too lean. If I pull the choke all the way out it works better. What did I damage? :eek:
1 - 8 of 16 Posts
When I initially choked the carb I rev'd it up and shoved a rag in the throat of the carb. Pulling the choke(enricher) cable all the way out now makes it accept throttle much better as does covering most of the throat of the carb as if I was closing a choke flap on a automotive carb. It idles great. Could I have damaged a diaphragm or ????
I suspected diaphragm as soon as it happened. I should have read up a little before trying a old CAR trick knowing the bike carb wasn't the same. Just a dumb mistake by a impatient rider looking for a quick fix. Oh well, live and learn. Fortunately there are kind people willing to help those of us who make dumb mistakes.
OK, while I'm at it .... my carb is factory original, never tweaked. It has always had a slight flat spot right off idle and typically runs lean from what I have read many times before. If I'm going into the carb would you have a suggestion as to what I should do while I have it off? I live in central Florida so conditions are mostly hot with high humidity. My driving habits are pretty tame with the occasional need to romp on it. Primary goal is mileage.
Thanks for the continued help.
Well, apparently the previous owner was into the carb right after he bought it. I pulled the upper section apart and the needle retainer has been clipped, SCAR mod. Now the question I have is, does the factory needle have more than one clip position? My needle has 5 which made me wonder, why shim when the clip can be moved? Leading me to believe that this is probably a re-jet kit since the bike already has V&H pipes on it.
Now what? lol
I only used SCAR as a reference, not to give credit where it wasn't due. I knew you guys that have been doing this for some time would know what I was talking about. I used SCAR because anybody else that is newer to carb mods would most likely have read about "SCAR" before and would have an idea as to what was going on here. Just trying to make things easier to follow for us rookies. :confused:

Got the carb back together and the bike runs great. Nice snappy throttle response off idle now and runs well in the mid range. Didn't get a long enough run to really get it up there but should be fine. Either cleaning fixed the throttle issue or something was stuck/jammed. Either way it looks like no damage to diaphragms was done. WHEW!
OK Charlie, here's what got me to try this failed initial action in the first place. You had suggested to myself and others to do a jet cleaning(not by stuffing a rag in the carb lol), on another thread, to straighten out vibration issues that we are having. Carb cleaned and tuned now but vibration is still there. There has always been a RPM range that gets the right harmonics going and vibrated, not terribly hard but a good fast buzz through the entire bike. Last time I headed out for a ride it seemed to be suddenly worse starting at lower RPMs and increasing intensity with engine speed. Not the usual sweet spot. Almost like a weight fell off somewhere or a crack. Using automotive terms, like a flexplate cracked making a normal little vibration much more intense. It goes away instantly when the clutch is disengaged so it has to be engine related. Any history of that? I just don't want to be buzzing, literally, down the road and have some disintegrate.
See less See more
Certainly didn't take any offense to your comment Bill and appreciate your input. I took it as you intended. I know text conversations can be easily misconstrued so I don't read between the lines. I wait till someone really gets crappy with me before a attack. LOL
Being a former auto mechanic I know all about bench made carb mods. Plenty of racers and conservationists out there trying to get every BTU out of a ounce of gasoline.
Alrighty then. If playing with jets and needle settings might get smoothness back in the machine I guess I'll have to see exactly what jet is in my carb and start some testing. I'll leave the custom emulsion tubes for you(seen on other threads). As long as I can get good mileage and can still embarrass my friends Heritage I'll be fine. hehehe I love hearing his Squealing Eagle ..... behind me. :bleh:

Thanks for all the help and cool riding!
Something obviously changed the bike and immediately after a fill up. I might just deal with it through this tank and see if the next fuel up fixes the severity of the vibration. Maybe it's just a crappy load of fuel? I never used this particular location before and it's a trashy looking place. Maybe those dirt bags are pulling something weird in their tanks. I threw in some SeaFoam just for the hell of it in case there are any water issues.
Before this happened my vibration was around 55. On local highway runs I either had to piss off traffic or run a little over the limit. Not being one to anger people in vehicles much larger than mine
1 - 8 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.