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Discussion Starter #1
I purchased a 03 VTX1300 over the winter. It was running great, though idling a little high. I talked to a mechanic and he recommended I adjust a particular valve. I'm not sure if this is the A/F Valve or not(see below)

I adjusted counter clockwise and the idle went down slightly, but it backfired badly after turn off. I tried to adjust back (clockwise), but the idle went up higher very quickly. Now, I can't turn it any further counterclockwise and it's still idling high. I only have about 90 degrees of turn, and it goes from high idle to very high idle. Additionally, now it backfires even louder after turn off. Seems like I should be able to undo what I did, but I'm not able to.

I removed the air filter and found what I believe to be oil. I removed this, hoping it was the problem.

The backfire is now quieter, but still there.

I've researched the SCAR method, but I'm not sure if this is necessary or if it will fix the problem. I'm also not sure if the oil is the cause of the problem or just a symptom of it. It seems that I just need to be able to adjust this down a little, but something is preventing it.

Does anyone have any suggestions?

ps. I'm coming from a much smaller, much simpler bike, so please stay as basic as you can with terminology.
 

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that is just the idle adjuster.
the oil is from the crankcase breather that is hooked up to the stock air box.

I would get some seafoam and run a tank or 2 with it in there.
+1
IF you can't find Seafoam (It's in most parts stores) put some Berrymans B12 Chemtool in there. It works real good, but do not get it on your paint.

Pull your airbox and check to see if your idle adjuster cable is kinked and make sure it is in it's slot in the back of the airbox.
This could be part of the problem in adjusting the idle.
While you are there, clean and lubricate your carb linkage.
 

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Discussion Starter #4
Been running with Sea Foam already. about 1 1/2 tank in.

I'll pull the air box tonight and check the cable and connection. I'll post results.

On the idle adjuster, I've been adjusting the black 'knob', but I see that there is a screw also. I have not broken the seal on this screw, as it's stuck and I don't want to strip. Should I adjust this at all or stick to the outer knob?

When you (CharlieD) wrote: "the oil is from the crankcase breather that is hooked up to the stock air box.", what exactly does this mean. Is this a concern for continued problems or do you think as long as I clean connections and tubes this problem will not continue?

Thanks for your help. I'm new to the forum and very impressed so far.
 

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The oil and gunk that collects in that drain is normal...Nothing to worry about...That's why that drain is there...The A/F screw you mentioned in the first post is in the bottom of the carb, and not the easiest thing to get to...Are you still running the stock pipes and airbox???...
 

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Discussion Starter #6
As far as I can tell it's stock pipes and airbox. It's an 03 that had under 3k miles when I got it, so it hasn't been messed with much.

I am having a hard time turning the idle adjuster cable more than a quarter turn. All of my 'fussing' so far has been with the idle adjuster. As I understand it, this is different from the A/F screw. Should I be going for the A/F screw instead?

Additionally, if anyone knows if the idle adjuster knob vs.actual screw will have different results. As I mentioned, I haven't been able to get the actual screw (which is housed inside of the knob) to budge. I don't want to strip the screw, as it's in a peculiar location.
 

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Never heard of problems with the throttle screw. It does snap out of it's position by pulling it towards you. It's held in place with a U-shaped metal piece. This may give you more movement with it.

If you start screwing with the A/F screw, you will definitely have to also readjust the idle screw to compensate for the change it casues. If you are having to use the choke to start the bike, you need to open the A/F screw a 1/4-1/2 turn counterclockwise.
 

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Spats, I just got my 2003 last september, with 2400 miles on it. It basically would not run without some choke, and was backfiring, spitting, sputtering, et. The plugs were badly fouled from the previous owner forgetting to turn off the choke. Champions are 2.99 each at autozone, and I got a glenns a/f tool and backed out the af screw. I also did the clayton mod and added a k and n filter, and it is like a different bike, amazing low end pull now compared to when I got it. Oh also did the pair valve removal, that gets rid of a lot of the popping on deceleration.
 

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Charlie D...I bought the plugs yesterday on your post advise from a few days back. What gap do you recommend, .044?
 

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Discussion Starter #14
It ended up being the Idle Adjuster. Somehow it had gotten jammed on the high end. Running great now.

Thanks for all the suggestions.
 
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