First Ride of Season - Not so Good.. with a couple pictures

My first ride of the season did not go well. I took 200 mile trip, bike ran flawlessly.... the next day to come back home, had some hesitation develop as well as popping from up front... not backfiring from exhaust.

So I've just completed the following:

-Removed, cleaned and replaced carbs (new float bowl o-rings)
-New Air Filter (and sub air filter)
-Oil + filter Change
-Correctly gapped, new spark plugs
-Coolant & radiator Flush
-New Carb Insulator boots
-Replaced Thermostat + o-ring

So, The bike is back together, all this stuff done plus I replaced the rotted out, torpedo of an exhaust with a nice 14" high mount, and threw on a nice set of Michelin PR4's. to round everything off...

Got on the road with a couple buddies for a weekend trip. 200 miles, bike ran flawlessly - better than it's ever been before.

Finished the journey there, parked the bike for the night. Temperatures dropped down to about 50 degrees and the next morning around 8am when I fired it up go for a morning spin, I went through the normal routine. Cranked and slowly opened the choke....waited a little, closed choke, ran fine. Made my way out of the campground, about 2 or 3 miles later I come to the first light. That's when it started stumbling and sputtering, with intermittent popping coming from the front (not backfiring from exhaust)

This is an intermittent problem, and seems to happen MOSTLY under load, when in gear. At idle, the idle drops a bit and when you give it gas it sometimes stutters as well.

I'm scratching my head again and wondering if I got some bad gas before arriving at my destination, or maybe if the condensation from overnight had anything to do with it?

I'm searching for starting points. If I have to remove carbs again at least now I know what to expect since I've already done it.

Also, I threw in these pics of the Delkevic because when I searched before buying, I couldn't find any pictures of this size in the high mount position. I'm happy to report that install was easy, this is a very high quality pipe, and the sound with the baffle in sounds superb.. mellow idle but when you open it up it just growls. For me, the baffles in are enough. I'm sure there are others that might want more, but this thing was turning heads all over the place down at the beach. I hope these pics help someone else with the same bike.

Anway, any starting points?

 

I maybe way off. But i had a bike that ran like crap intermittently. ....once the air intake leak got bad enough i was finally able to figure out why. But wish i had thought of that and new to check for it earlier. ....so if you eliminate everything else maybe check the carb to engine boots....and all seals on the carbs themselves.

 

Fuel pump? Fuel filter?


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I have to find time this week to mess with the bike and take it apart once again. FSM troubleshooting section says to "check air intake". When I pulled over initially my first thought was to check vacuum lines, carb insulator boots, etc.

Fuel filter is new, but will check again...

 

Haven't had a chance to look the bike over just yet.

Anybody have any ideas about why, on the way down to the beach (220 miles) bike never acted up, then the next morning, it started having any issues?

I believe for the most part, I can eliminate the fuel and air, so that leaves spark.. maybe ignition?

I'm not sure where to begin looking.

 

Water in the gas tank - do you use ethanol mixed fuel?

 

I'm thinking coils, my CB is doing my head at the moment and the only thing I haven't changed is the coils recently

 

yea a little water will make it sputter, did you use any fuel stalizer. I now think adding a little isn't a bad idea-I don't ride too much, its too muddy

 

Thanks for all replies, guys...

LATEST DEVELOPMENTS:

So last night I finally had some time in the garage to take fairings off and look things over...

Vacuum hose was completely OFF of the #4 cylinder port - Placed this hose back with some silicone lube and fired it up. Did a quick check of all connections, all seemed fine. Fired it up and started fine, warmed up fine.. no erratic idle or otherwise.. Fuel tank was about 1/4 tank...

Put everything back for a test ride.. rode fine about 1.5 miles to gas station.. filled up and added about 1 ounce of STARTRON fuel stabilizer, 2 minutes later to go back home and it's still hesitating, stuttering and popping on acceleration. After about 5k rpm it's fine.. This popping seems to be muffled and sounds to be coming from the front.

Got it back home, panels off, checked hose again and it's still on, but loose. This is to say, due to the silicone lube, it can easily be slid on or off... All other hoses/caps OK.

Could the looseness of the hose be causing this f'n issue??

Been searching these forums like crazy and will soon bust out with multimeter and check connections... I've read in other posts that suggest coils - especially when the bike is nice and warm. Could this cause the bike to drive fine initially to the gas station then act up once it's warm? Maybe the full tank at fill up? This bike is forcing me to get to know everything about it, but I'd rather be out riding it, instead.

What's my next step here?

 

I was going to suggest coils/wires/spark plugs. How old are the plugs? Sometimes if they have a crack in the ceramic insulator they can misfire when hot. Does it sound like one cylinder is dropping out?

 

Plugs were just changed out for what the FSM calls for (correct temp range), and gapped properly.

Yeah, it sounds like one cylinder cuts out.. this is beginning to drive me nuts.

Get this bogging/missing/hesitating, and occasional muffled popping from up front under acceleration - ONLY until about 4,500 RPM then it "catches" and rides fine.

I think that's key to understanding this issue: the fact that it stops acting up after about 4,500 RPM

 

Do you ride with a tank bag?

 

No, not for a long time now. Why?

 

Tried running it with the air filter out after it starts acting up just to get a good look at what's going on? Maybe you have an over-fueling issue.

 

Have not tried this yet... however, do you all think this issue has anything to do with the new Delkevic exhaust that was installed recently? I would say no, simply due to the fact that I did 220 miles after install with no issues until that next morning...

 

Ok, so finally had some free time this weekend to get my hands on the bike again and begin troubleshooting the ignition system. I think I'm making some headway, finally...

As per the FSM on section 16-6, I've tested:

-FIrst, the battery: I've begun with a charge of 12.5V...

-ICM connectors, all checks out OK

-Primary coil resistance on all four - OK

-Secondary coil resistance on all four - OK

-IGNITION PULSE GENERATOR - NOT OK.. disconnected the 4P connector, cleaned it up, measured resistance between the white/yellow-yellow; result: within range at about 295 ohms.

Measured resistance between the other pins; the yellow-white/blue terminals; result: NO READING.

Plugged everything back up, started the bike to get to the point where it "misses" again at operating temperature so I can compare readings,but this time it began to "miss" only about 2 minutes after turning it on. Took the readings anyway, and the 295 reading shot up to about 330 ohms, while the other one that had no reading remained at no reading...

So....am I to conclude that the problem I've been experiencing lies with the pulse generators, then? I'd like to be sure before opening the side of the engine case and possibly buying a used one on eBay

 

Ok, so I ordered another pulse generator off of eBay...

Resistance from the yellow to white/blue terminals OL.....

what are the odds that the resistance readings of this "new" used part STILL measure about the same as the ones on my bike?

The only exception is the white/yellow-yellow measurement. The one on the bike:295 ohms; the new one I just got: 305. Both within the FSM specs.

Am I missing something here??

Help??!

 

Third PG purchased so far and third unit that's giving me a bad reading, according to the test in the FSM.

Not sure where to go from here anymore...

 

has been bookmark, This seems like a very interesting thread.