Took her for the 1st run today - Backfires a lot while cruising!!

[warthogcrewchief]

I pulled out the battery tray today (after having to drill out the battery tray bolts!). I tested the ignition coils and the pickup coils from the connector at the TCI/CDI.

 

For all four ignition coils, I was getting around 3.3-3.4 ohms. For all four pickup coils, I was getting around 111 ohms.

 

So, I'm not worried about the pickup coils, but the ignition coils seems to be a little bit out of the tolerance range of 2.7 +/- 10%. Does this seem alright? I have another set of coils I bench tested and they get around 3.0 ohms.

 

There doesn't appear to be any corrosion on the pin outs on either the TCI/CDI or the connectors. The only thing I haven't done is replace the plug wires/caps (which I have on order).

 

I am STILL waiting for my Carb Tune Pro so I can properly tune the carbs...

 

Any ideas, does this seem alright?

 

Thanks again for all your help!

 

EDIT:

I did the simple test to see which cylinder was not getting spark. Turns out I'm not getting spark to the right rear cylinder. So, I'm gonna have to pull all the plastic off and recheck the spark plug wire connection to the coil.... or just wait for the new wires to show up.

Edited March 5, 2010 by warthogcrewchief

[wes0778]

 

I am STILL waiting for my Carb Tune Pro so I can properly tune the carbs...

 

 

If you want a quick fix to get them in the "Ball Park", run down to Harbor Freight and pick up two of their $12.00 vacuum gauges. Hook them up on the two right carbs, sync them (screw on right side), move the gauges to the left side, sync them (the screw that takes the LONG screwdriver) then move the gauge from the left rear to the right rear and sync them (Screw on the left side). It won't get you as exact as the Carb Tune will, but will be close.

 

As a side note, you will either have idle the engine up a good bit to stop the "stop to stop" needle oscillation, or you can pinch the rubber tubing, to create the dampening.

[Squeeze]

The Procedure is listed wrong for the 1Gen.

 

It's first #1 to #2(both left), then it's #3 to #4(right Side) rear Screw, finally right side to left Side with the right front Screw.

[wes0778]

The Procedure is listed wrong for the 1Gen.

 

It's first #1 to #2(both left), then it's #3 to #4(right Side) rear Screw, finally right side to left Side with the right front Screw.

 

 

OOPS!!!

[warthogcrewchief]

Well, I'm going to want to fix the no-spark issue before I attempt the carb adjustment. I think not having spark on the right rear cylinder could possibly skew the readings.

[mbrood]

You can get to the coil of the right rear with the battery out... pull the high tension lead and trim 1/4" and shove it all back... do the same at the plug holder... odds are she will fire again.

 

Ohming from the ignition fuse to the inside of the plug holder should show about 23K... 10k for the resistor in the plug holder and 13k for the coil... much more and it's most likely a bit of corrosion on one end of the spark plug wire.

[vic venture]

Have you got that fresh gas in yet? I got too much seafoam in mine and it ran awful and backfired often. Once I ran it down to the last bar and filled it up, she smoothed out and ran pretty. Still got a flutter about 3500 rpm but I have not gotten all that seafoam out yet.

[warthogcrewchief]

I have filled it up once. The backfiring has reduced significantly as I have been riding, but still occasionally spits. My big thing right now is to get the right rear cylinder running and the carbs synced.

 

I did trim the spark plug wire down on the cap side, and intend to do so as soon as I can access it. I'm not sure what's easiest to do: pull the fairing or the battery to replace the wires. I might try to pull the battery again and see if I can access...got ALL weekend and it's expected to rain...good time to work the bike!

 

Thanks again for everyone's help!

[warthogcrewchief]

I replaced the spark plug, spark issue solved. I synced the carbs last week, surprisingly close before I started, but now they're even closer.

 

This afternoon, she started to spit a little bit again (not much, but she shouldn't spit at all). On top of that, the idle began to rise to about 2500-3000 RPM. I was able to adjust the idle screw down, but it came right back up a little later. I hooked up the carbtune and it was off just a little. I set them again and went to get more gas. She still spits a little, and the idle issue isn't solved. I can set the idle down, but it sits around 750-900 RPM (too low for a good idle), and is hard to set it to the right RPM with the idle screw. It almost seems as if it's unresponsive. Every now and again, it'll spit and it will kick up the RPM just a bit (about 100 RPM). I noticed this on the carbtune and it seemed to do this on all four carbs.

 

I wondering if it's fuel delivery, exhaust or possibly a leak? I'll have to check for an air leak later using some cleaners.

[GigaWhiskey]

Sounds like when she is warmed up a bit it starts that. Brownie will idle ok until I get down the road a mile or two and then the idle start climbing a bit. Tiz why I have her apart. Gonna ditch the YICS and waiting on new carb boots and o-rings from MiCarl, hoping it solves it.

 

This bike has idled ad 450 before and it held well.

 

In the past I sprayed something around the front bank and it started to act right. Making me think I have an air leak somewhere there.

 

Just thought I would throw that in. Pay me no mind.

[warthogcrewchief]

This is what I've replaced so far during my rebuild/restoration:

- air filter

- carb boots/o-rings

- carb diaphragms

- spark plugs (twice)

- spark plug wires/caps

-vacuum caps and clamps

- replaced breather vent tube with filter element (plugged air box holes with vacuum caps)

 

Things I've done:

-tore carbs apart and cleaned

-tested coils

- synced carbs

-sea foamed gas

 

 

That only leaves a few things left to look at...unless something I already did failed or wasn't done correctly.

 

Exhaust - maybe, but not likely, didn't see/feel any leaks

carb internals - didn't mess with the float settings, but it should be okay (not pissing fuel)

fuel filter - doesn't seem like fuel starvation, but haven't ruled it out yet

possible air leak - seems like the most plausible culprit (and potentially the easiest fix)

[GigaWhiskey]

Ok Warthog, I will shut up now.

[Squeeze]

Carefully spray some Brake Cleaner around the lower Carbs and the Intake Manifolds while the Motor is running on Idle, if the RpM rise, you found the Culprit, it still sounds like a Vacuum Leak.

[warthogcrewchief]

Ok Warthog, I will shut up now.

 

Nah, it's alright. I appreciate the input. I too think it might be a vacuum leak...just not sure where yet...might take it to the parts store and buy some brake cleaner or carb cleaner (Carb-Out causes RPM to drop and I know it works for carbs).