won't start-backfires

develly · 07-07-2008, 11:26 PM

Hi all, new to site, lots of great info on here but I haven't come across the
problem I'm having, so here goes. I've got a 95 roadking, this spring it started running irratically,even just dying a couple times after running good.I replaced fuel valve, wires, plugs.Now it won't start and back fires as I'm trying to start. Plugs have consistantly had black soot build -up, and I haven't been able to see any air/vacuum leaks. Any ideas? Thanks in advance.

dangerdan · 07-07-2008, 11:40 PM

Have you tested your V.O.E.S. There is some great info in the self help section.

VOES Switch Explained - Harley Davidson Community

Make sure there are no cracks/leaks in the vaccum line.

glider · 07-08-2008, 08:50 AM

You have to test for vacuum leaks, they aren't something you can see as you stated.

Finding An Intake Leak - Harley Davidson Community

Also try to find out if you have constant spark at the plug when this happens.

TQuentin1 · 07-08-2008, 09:04 AM

1995 RK. Hmmm. Not sure this applies if you don't have fuel injection. Can't remember when HD put that on the touring bikes. If it does, check to see if you have convoluted tubing in your gas tank. It may have worn tiny pinholes through the tubing rubbing against the interior of the tank. Especially if it starts and runs fairly normally if the tank is full of fuel.

Must still be the EVO engine. So the above probably does not apply. If you have tried everything in the posts above and still are having problems, consider upgrading your ignition system and doing away with the VOES all together. I went with the Spike ignition module and coil on my '91 Dyna and never looked back.

TQ

develly · 07-08-2008, 01:17 PM

Thanks, I'm going to narrow in on the vacuum. Crazy question, if I took the vacuum hose from fuel petcock and blow air in and used soap to test for leaks would that work , or is there another test your aware of?

glider · 07-08-2008, 02:02 PM

If you use a vacuum pump , that would do it. Look at the post in my last reply.

dangerdan · 07-08-2008, 02:30 PM

Dont laugh, as I did not have a vaccum pump and this was a a quicky test.

I stuck an ohm meter into the end of the VOES connector, placed the meter on beep, sucked slowly on the VOES with my mouth till I heard a beep.

This worked for me , its not for everyone as there are many dangerous contaniments even after wiping down the unit..

glider · 07-08-2008, 02:32 PM

Nothing wrong with that Dan.

develly · 07-08-2008, 05:39 PM

Thanks for the great advice guys, I've got the bike running now. Sounds a little off though, I don't have vacuum pump/gauge so wll have to wait on that, but I did notice the left exhaust is cool and the right is hot, I'm assuming that isn't normal, I've never noticed that before. Oh, I also tried spraying wd-40 around manifold while bike running and did'nt notice any change in sound.But that exhaust has me a little concerned any ideas???

glider · 07-08-2008, 07:04 PM

Quote:

Originally Posted by develly

Thanks for the great advice guys, I've got the bike running now. Sounds a little off though, I don't have vacuum pump/gauge so wll have to wait on that, but I did notice the left exhaust is cool and the right is hot, I'm assuming that isn't normal, I've never noticed that before. Oh, I also tried spraying wd-40 around manifold while bike running and did'nt notice any change in sound.But that exhaust has me a little concerned any ideas???

Check the compression.

07-07-2008, 11:26 PM	#1 (permalink)
develly New Family Ride: 1995 Roadking Join Date: 2008, Jul 06 Posts: 5	won't start-backfires Hi all, new to site, lots of great info on here but I haven't come across the problem I'm having, so here goes. I've got a 95 roadking, this spring it started running irratically,even just dying a couple times after running good.I replaced fuel valve, wires, plugs.Now it won't start and back fires as I'm trying to start. Plugs have consistantly had black soot build -up, and I haven't been able to see any air/vacuum leaks. Any ideas? Thanks in advance.

07-07-2008, 11:40 PM	#2 (permalink)
dangerdan Community Star Ride: 1995 FLHTC Join Date: 2007, Oct 14 Location: Ontario Posts: 465 My Mood:	Re: won't start-backfires Have you tested your V.O.E.S. There is some great info in the self help section. VOES Switch Explained - Harley Davidson Community Make sure there are no cracks/leaks in the vaccum line.

07-08-2008, 08:50 AM	#3 (permalink)
glider Community Liaison Ride: 07 Road King Classic Join Date: 2007, Jun 21 Posts: 10,315 My Mood:	Re: won't start-backfires You have to test for vacuum leaks, they aren't something you can see as you stated. Finding An Intake Leak - Harley Davidson Community Also try to find out if you have constant spark at the plug when this happens. __________________ Psssst! Please stop by the "self help section" for maintenance tips, diagnostic codes and much more. click me!>>Self Help Information and Tips<< click me!

07-08-2008, 09:04 AM	#4 (permalink)
TQuentin1 Moderators Ride: '03 FLHTCUI Join Date: 2008, Apr 04 Location: Missouri City, TX Posts: 451	Re: won't start-backfires 1995 RK. Hmmm. Not sure this applies if you don't have fuel injection. Can't remember when HD put that on the touring bikes. If it does, check to see if you have convoluted tubing in your gas tank. It may have worn tiny pinholes through the tubing rubbing against the interior of the tank. Especially if it starts and runs fairly normally if the tank is full of fuel. Must still be the EVO engine. So the above probably does not apply. If you have tried everything in the posts above and still are having problems, consider upgrading your ignition system and doing away with the VOES all together. I went with the Spike ignition module and coil on my '91 Dyna and never looked back. TQ Last edited by TQuentin1 : 07-08-2008 at 09:18 AM. Reason: facts straight!

07-08-2008, 01:17 PM	#5 (permalink)
develly New Family Ride: 1995 Roadking Join Date: 2008, Jul 06 Posts: 5	Re: won't start-backfires Thanks, I'm going to narrow in on the vacuum. Crazy question, if I took the vacuum hose from fuel petcock and blow air in and used soap to test for leaks would that work , or is there another test your aware of?

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07-08-2008, 02:02 PM	#6 (permalink)
glider Community Liaison Ride: 07 Road King Classic Join Date: 2007, Jun 21 Posts: 10,315 My Mood:	Re: won't start-backfires If you use a vacuum pump , that would do it. Look at the post in my last reply. __________________ Psssst! Please stop by the "self help section" for maintenance tips, diagnostic codes and much more. click me!>>Self Help Information and Tips<< click me!

07-08-2008, 02:30 PM	#7 (permalink)
dangerdan Community Star Ride: 1995 FLHTC Join Date: 2007, Oct 14 Location: Ontario Posts: 465 My Mood:	Re: won't start-backfires Dont laugh, as I did not have a vaccum pump and this was a a quicky test. I stuck an ohm meter into the end of the VOES connector, placed the meter on beep, sucked slowly on the VOES with my mouth till I heard a beep. This worked for me , its not for everyone as there are many dangerous contaniments even after wiping down the unit..

07-08-2008, 02:32 PM	#8 (permalink)
glider Community Liaison Ride: 07 Road King Classic Join Date: 2007, Jun 21 Posts: 10,315 My Mood:	Re: won't start-backfires Nothing wrong with that Dan. __________________ Psssst! Please stop by the "self help section" for maintenance tips, diagnostic codes and much more. click me!>>Self Help Information and Tips<< click me!

07-08-2008, 05:39 PM	#9 (permalink)
develly New Family Ride: 1995 Roadking Join Date: 2008, Jul 06 Posts: 5	Re: won't start-backfires Thanks for the great advice guys, I've got the bike running now. Sounds a little off though, I don't have vacuum pump/gauge so wll have to wait on that, but I did notice the left exhaust is cool and the right is hot, I'm assuming that isn't normal, I've never noticed that before. Oh, I also tried spraying wd-40 around manifold while bike running and did'nt notice any change in sound.But that exhaust has me a little concerned any ideas???

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won't start-backfires

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