I've moved this to the 1300 Riders board for you. The How To;Step-by-Step board if for threads showing How To do things. Questions and troubleshooting goes on the 1300 Riders and 1800 Tech boards.
Thanks
Thanks
Engine Backfire after carb work could use some help.
my 2003 VTX1300S was fouling plugs so I had carb rebuilt and rejetted. The new jets were recommened and I stepped up one larger size from factory. It now runs better but it backfires through the exhaust. It never did this before. It does this when engine is throttling down from acceleration. I have ridden about 500 miles since the rebuild and it is getting worse. I also had an external mixture installed but adjusting that doesn't make a difference. SHould I change out the air filter or am I asking for more trouble?
1 - 8 of 8 Posts
If you were fouling plugs before, increasing the main jet likely only made it worse. Decrease the main jet and adjust the needle (need a rejet kit to do this). You can also remove the PAIR system to eliminate fresh air into your exhaust.
No matter which road you go down, you need to pull the plugs and check them for fouling. If they are fouled again, decreasing your main jet is going to be necessary.
No matter which road you go down, you need to pull the plugs and check them for fouling. If they are fouled again, decreasing your main jet is going to be necessary.
With all due respect ..Ive never under stood why folks dick/diddle with a perfectly good carb. Platform….2 1/2 turns out on the A/F and mine runs faster than my guardian angel can fly…good luck OP…
I would agree most of the time but the motorcycle was stalling and getting worse. It was obvious something was gummed up. It was indicative of the fast idle assy being clogged. That has gone away completely since the clean up. I have ridden about 500 miles since the repairs so I will pull the plugs this weekend to see how they look. I left it up to the shop to decide on whether to increase the jet size. I think it could be a lean problem. There is no smoke and no indication of carbon at the tailpipe.With all due respect ..Ive never under stood why folks dick/diddle with a perfectly good carb. Platform….2 1/2 turns out on the A/F and mine runs faster than my guardian angel can fly…good luck OP…
Thanks
BY the way I will try the mixture at 2-1/2 turns. It is easy to access now because I had them install an external mixture adapter that I can actually reachI would agree most of the time but the motorcycle was stalling and getting worse. It was obvious something was gummed up. It was indicative of the fast idle assy being clogged. That has gone away completely since the clean up. I have ridden about 500 miles since the repairs so I will pull the plugs this weekend to see how they look. I left it up to the shop to decide on whether to increase the jet size. I think it could be a lean problem. There is no smoke and no indication of carbon at the tailpipe.
Thanks
at the risk of sounding stupid what is the PAIR system?If you were fouling plugs before, increasing the main jet likely only made it worse. Decrease the main jet and adjust the needle (need a rejet kit to do this). You can also remove the PAIR system to eliminate fresh air into your exhaust.
No matter which road you go down, you need to pull the plugs and check them for fouling. If they are fouled again, decreasing your main jet is going to be necessary.
PAIR - Pulsed Air Injection pumps air into exhaust port to burn residual Air/fuel.
Stock pipes have many chambers, relatively quiet exhaust.
Straight pipes - with PAIR creates loud explosions.
Blocking off the PAIR usually keeps things quiet.
Verify rubber vacuum hoses, look at the end of each hose.
Removing/Blocking the PAIR could possibly eliminate your issue.
Usually the reed valve cover is replaced with a flat plate.
I have blocked the reed valve cover hose bib with a bolt and epoxy.
You can remove one vacuum Tee and hose to PAIR.
I blocked off the PAIR inlet in the airbox with a bolt and RTV.
Be careful when putting the airbox back on. The crappy rubber engine vent hose
can be kinked if too many gyrations made. The result could be a crankcase
vent blockage which will pop off the shifter shaft seal on the engine
creating an oil leak in front of the rear wheel.
From the left side of the engine I can see the vent hose direct to air box.
Stock pipes have many chambers, relatively quiet exhaust.
Straight pipes - with PAIR creates loud explosions.
Blocking off the PAIR usually keeps things quiet.
Verify rubber vacuum hoses, look at the end of each hose.
Removing/Blocking the PAIR could possibly eliminate your issue.
Honda VTX 1300 Desmog | Bareass Choppers Motorcycle Tech Pages
This is a walk-through for removing the PAIR valve assembly, and all the hoses and junk that are associated with it, on the VTX 1300 49 state model. I have never dealt with a CA model (living in Louisiana) so if anyone wants to take good quality pics, write a description and email it all
tech.bareasschoppers.com
I have blocked the reed valve cover hose bib with a bolt and epoxy.
You can remove one vacuum Tee and hose to PAIR.
I blocked off the PAIR inlet in the airbox with a bolt and RTV.
Be careful when putting the airbox back on. The crappy rubber engine vent hose
can be kinked if too many gyrations made. The result could be a crankcase
vent blockage which will pop off the shifter shaft seal on the engine
creating an oil leak in front of the rear wheel.
From the left side of the engine I can see the vent hose direct to air box.
1 - 8 of 8 Posts
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