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Discussion Starter · #1 ·
Hello all,
I'm needing help in the worst way. I've hit a wall trying to tune my carb. I'll start by listing what I've done so far. I'll include pics of exhaust, and choke delete.

1) Stock exhaust mod: gutted two chambers, removed one baffle, shortened mufflers by 4 inches.
2) PAIR delete, installed Goheen dimpled plates.
3) Stock airbox decap, still running HiFlo air filter.
4) choke delete, spring was still taught so added screw upside down to create more tension so valve would remain closed.
5) Installed Glen's permanent A/F screw.
6) Installed Keihin 58 main jet.
7) Installed Keihin 198, 200, 202, and 208 pilot jets, all made bike run WAY too rich. Reinstalled factory Keihin 195, still running WAY rich
8) Replaced vacuum line from petcock, checked fuel line from petcock, flow is great!
9) Replaced float needle with OEM Honda part.
10) Checked and cleaned spark plugs after each test run, checked for spark, all are great. Tried gapping at .035 and .032...runs better at .032.
11) Also changed coolant, and triple checked oil level. Still have 2000+ miles till due for change.
12) Replaced diaphragm had huge cracks.
13)Did Scar mod, clipped the tit, tried 2 washers, ran too rich and seemed to run fat the whole ride. 1 washer ran best on maiden voyage. Great acceleration, no backfire, little rich but not bad. Let sit 2 hours rode 1 mile, died. Adjusted A/F to lean out, turned idle up by tiny turn. Ran ok. Died 3 more times during the day, each time I leaned it out more.
Removed the one washer from jet needle, now boggs down and unrideable.
Currently set at 1.25 turns out on A/F screw, idle is probably 900-1200 rpms.

Help please! This is my only transportation right now. I'm stuck 18miles away from town in the country, so can't make it in to do ANYTHING.

Thanks,
Moose
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2004 VTX1300s
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9 Posts
Discussion Starter · #2 · (Edited)
Hello all,
I'm needing help in the worst way. I've hit a wall trying to tune my carb on my '04 VTX 1300s. I'll start by listing what I've done so far. I'll include pics of exhaust, and choke delete.

1) Stock exhaust mod: gutted two chambers, removed one baffle, shortened mufflers by 4 inches.
**NOTE: Bike was running fine, but rich for about a week. Then REALLY rich and fuel mileage suddenly decreased dramatically. So, I researched and did the following.

2) PAIR delete, installed Goheen dimpled plates.
3) Stock airbox decap, still running HiFlo air filter.
4) choke delete, spring was still taught so added screw upside down to create more tension so valve would remain closed.
5) Installed Glen's permanent A/F screw.
6) Installed Keihin 58 main jet.
7) Installed Keihin 208, 202, and 198 pilot jets, all made bike run WAY too rich. Reinstalled factory Keihin 195, still running rich, but much better.
8) Replaced vacuum line from petcock, checked fuel line from petcock, flow is great!
9) Replaced float valve with OEM Honda part.
10) Checked and cleaned spark plugs after each test run, checked for spark, all are great. Tried gapping at .035 and .032...runs better at .032.
11) Also changed coolant, and triple checked oil level. Still have 2000+ miles till due for change.
**NOTE: The bike was not ridable until the next steps were done.
12) Replaced throttle piston diaphragm, had huge cracks.
13)Did Scar mod, clipped the tit, tried 2 washers on stock jet needle, ran too rich and seemed to run fat the whole ride. Tore down AGAIN and noticed the air line from airbox to the head had come off at the airbox. Went ahead and removed 1 washer from her needle, and it ran best on maiden voyage. Great acceleration, no backfire, little rich but not bad. A/F was a little more than 1.5 turns, idle was a little low. Let sit 2 hours rode 1 mile, died. Adjusted A/F to lean out, turned idle up by tiny bit. Ran ok. Died 3 more times during the day, each time after cool down, and everytime was immediately after shifting into 4th or 5th gear, and each time I trimmed it a little more.
Got home, let sit overnight. Removed the one washer from jet needle, checked plugs. They looked really good, cleaned anyway double checked gap at .032, reassembled...and now it bogs down and is unrideable.
Currently set at 1.25 turns out on A/F screw, idle is probably 1000± rpms.

The only two things I can think of:
1)Put the stock Keihin 55 main jet back in. I can't afford the K&N filter or the Factory Pro jet kit right now, but I'm not sure that'll even work at this juncture...
2)AND I didn't mark the piston when I changed the diaphragm. I realized it upon reassembly, so refered to the manual diagram and put it in as it showed. Read reassembly instructions and NOTHING is said about piston position, only diaphragm position.

I've tripled checked everything. Cleaned the carb everytime I pulled it or did anything for that matter. I don't understand how it ran fine with the one washer on the jet needle, then sits for 2 hours and runs rich all over again.

Help please! This is my only transportation right now. I'm stuck 18miles away from town in the country, so can't make it in to do ANYTHING.

Thanks,
Moose
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Discussion Starter · #3 ·
I somehow posted this here without new edits. Please see new updated/edited thread "Can't get carb retuned after mods"...can't figure out how to delete this one either. 🤔
Sorry,
Moose
 

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The Main jet #195 OEM
The low speed jet #55 OEM
Is the ACO connected to a vacuum source.
Do you have any signs of high fuel level in the carb?
Info on the carb. Carb Cleaning 101

Did it run correctly before you made all these high performance changes???
Did you replace the slide valve diaphragm with OEM??
 

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Discussion Starter · #5 ·
The Main jet #195 OEM
The low speed jet #55 OEM
Is the ACO connected to a vacuum source.
Do you have any signs of high fuel level in the carb?
Info on the carb. Carb Cleaning 101

Did it run correctly before you made all these high performance changes???
Did you replace the slide valve diaphragm with OEM??

Yes I have OEM Keihin 195 slow jet installed, but I installed the Keihin 58 jet per airbox decap instruction. Was going to go back to 55 to test it out.

I didn't mess with ACO, it should still have the vacuum line connected.

Had high fuel level before I replaced float valve with new OEM valve. Still has fuel in bowl because I drain it before removing, but is not high like before. Was pooling in bottom of air box before.

Diaphragm replacement is OEM.

It had begun to have dead spots in throttle before warmed up, and it did backfire often on decel, but that's all. That was before I modded the exhaust.
 

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Discussion Starter · #7 ·
The MAIN JET is the largest jet of the two.
The Main Jet is inline with the needle in the center of the slide valve.
The low speed jet is partially shrouded by the body.
Yes. I'm sorry I reversed the two by title. I changed the Slow Jet from the #55 to the #58 per the instruction of the super moderator on VTXCafe because I decapped the stock airbox. I also changed the main jet from the factory #195 to the #208, then down to the #200 then to #198 and finally back to the #195. All because the bike was running so rich it was puffing large amounts of black smoke. As I went down main jet sizes, the smoking decreased and the strong fuel smell as well.
I double checked that I had the right jets, that they were Keihin like what comes on the bike from the factory. I went to the Factory Pro website, and the replacement jets they send in their kit are Keihin, but they send their OWN jet needle with clips, which is longer than the stock jet needle that comes on the bike from factory. They give the measurements of both main and slow jets to compare by. The ones I have are also stamped with the Keihin "K".
 

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Discussion Starter · #8 ·
Yes. I'm sorry I reversed the two by title. I changed the Slow Jet from the #55 to the #58 per the instruction of the super moderator on VTXCafe because I decapped the stock airbox. I also changed the main jet from the factory #195 to the #208, then down to the #200 then to #198 and finally back to the #195. All because the bike was running so rich it was puffing large amounts of black smoke. As I went down main jet sizes, the smoking decreased and the strong fuel smell as well.
I double checked that I had the right jets, that they were Keihin like what comes on the bike from the factory. I went to the Factory Pro website, and the replacement jets they send in their kit are Keihin, but they send their OWN jet needle with clips, which is longer than the stock jet needle that comes on the bike from factory. They give the measurements of both main and slow jets to compare by. The ones I have are also stamped with the Keihin "K".
Do you think I should go back to the #55 slow jet?
Do you think I should put washers back on factory needle in the slide valve, per the Scar mod instructions?
 

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Do you think I should go back to the #55 slow jet?
Do you think I should put washers back on factory needle in the slide valve, per the Scar mod instructions?
Putting the shims back under the needle will make it richer from 1/4- 3/4 throttle.
The needle you received with the clips eliminate the need for shims, as you use the clip to raise and lower the needle in the main to change midrange jetting.
If you are rich, and have eliminated all other possibilities, such as ignition, or fuel level, then to lean it out in the mid-range you need to lower the needle in the main.
 

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Discussion Starter · #10 ·
Putting the shims back under the needle will make it richer from 1/4- 3/4 throttle.
The needle you received with the clips eliminate the need for shims, as you use the clip to raise and lower the needle in the main to change midrange jetting.
If you are rich, and have eliminated all other possibilities, such as ignition, or fuel level, then to lean it out in the mid-range you need to lower the needle in the main.
I actually didn't purchase the Factory Pro kit, so I don't have their custom jet needle with the adjustable height clips. I read a lot of threads here and on the Cafe that said as long as I got Keihin jets I could shim the STOCK jet needle with washers after doing the Scar mod. I understand now though that to do that would make it run more rich through the mid range. That's the opposite direction I need to go.

This is what I don't understand though. I've already removed all the washer shims from the stock needle, which should have lowered it. However, by doing the Scar mod, I clipped the tit in the jet needle holder by half as instructed.

So, if I go back to stock with both slow jet (#55), and main jet (#195), with the jet needle holder tit already trimmed, but no washer shims on the stock jet needle, will it lean out ANY? I can live with it running slightly rich as long as the plugs aren't fouling, just until I can purchase the Factory Pro adjustable jet needle, and the K&N air filter. Or, is there a different issue I need to address, by your guess?
 
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