Old Honda sputtered and then resolved itself...for now

[RVFRick]

Saturday night we were on southbound 880 returning from a fun day through Lake Berryessa and Napa. I had half a tank of gas. In the fast lane moving at 70-75mph in heavy but smooth traffic my '90 Honda CB-1 started to sputter.

The symptoms were exactly like a bike running out of gasoline. At first there was a slight hesitation/flat spot which I thought was my imagination. I rolled the throttle WOT and she hesitated but then responded, 2-3 seconds later she started to sputter and not respond. Crap! Fortunately the surrounding drivers saw my turn signal and arm waving and slowed so I could limp to the shoulder.

I checked the tank and saw plenty of gas. The petcock was set to RES as expected (I leave it on RES and rely on the trip odometer to monitor fuel level). I tried starting up but no joy.

This had never happened before. The only recent change to my bike was the 12V heated jacket that I had running part of the day. However I used it in the week prior with no issues. For this ride I used it in the morning, had it off during the day and only just tuned it back on 10 minutes earlier after we stopped for dinner. I doubt the battery was the issue since running at 70mph means 8k rpm and, I assume, enough electricity. Nevertheless, I unplugged the jacket from the battery. The bike sat for maybe 2-3 minutes before I tried the starter. After a minute of attempgs she sputtered back to life. :thumbup

The remaining 20 miles to home was as if nothing happened. I have no hypothesis except for the heated jacket straining the electrical system but I don't think it jibes with the the symptoms.

A few ideas:
1 Water got in the fuel - I doubt since it recovered itself and isn't this an old wives tale?
2 A dying rectifier. In old Hondas I've read rectifier/regulators are failure prone. But do the symptoms agree?
3 Old battery - I plan to test the battery at O'Reilly's.
4 Just ride it and bring AAA card in case I get stranded.

The CB-1 is a carbureted inline-four with a fuel pump. Any ideas how to proceed?

UPDATE: Evolution mechanics identified bad fuel pump after bench testing and running bike on aux gas feed. My battery failed load test after recharging. So I have a new battery, new petcock (I've had it sitting around for a while) and new Quantum fuel pump. Charo's been running fine. Only difference is the new pump has an audible clicking sound that I never noticed with the OEM pump but I think it pretty normal from what I've read online regarding fuel pumps.

 

[haybaler]

comprehensive approach

First I would drain the float bowls into something clean, and look for water.

Then I would go through and rebuild the entire fuel system, tank, petcock, fuel filter, fuel pump, fuel lines, carbs.

Would also consider close look at the way the gas tank vents, possible vapor lock problem.

 

[ST Guy]

To check VRR, hook meter to battery and run engine to 3-4000 rpm. Note voltage. Should be around 14.4.

Do not test your battery at OReilys. They are crap testers and will often not catch a bad battery. Or a good one for that matter. First step for checking yourself is to measure voltage at the battery, engine off.

Report back with findings.

 

[GottaRollWithIt]

Well, if it's vapor lock related, did the tank take a huge gasp of air when you opened it?
Shine a light in the tank, is there a buncha crap on the bottom?
Before tinkering with the fuel system, i'd rule out the reg and electrical system first. Then, before tearing up the whole fuel system, i'd see if there's an inline fuel filter - if there is, backflow it with some brake cleaner and see if it's gunked up with crud.
Start simple, easy, and cheap, then work your way up to diagnosis with more difficult stuff.

 

[DannoXYZ]

test and measure petcock's flow-rate. I've seen quite few cases where bad vacuum-line to petcock leaked and failed to hold it open.

 

[ST Guy]

I believe the reserve position on the petcock generally bypasses the vacuum operated aspect of the valve.

 

[ichabodnt650]

fuel pump (#1) instead of gravity fed, vacuum enabled petcock

 

[RVFRick]

fuel pump (#1) instead of gravity fed, vacuum enabled petcock

Yes, CB-1 has a fuel pump but the fuel cock is not vacuum actuated. I will give Charro a lookover this weekend.

 

[Tom G]

Friend has a Bandit where the tank would eventually run out of air. Since the bike was old he bought a V-Strom and dumped the bike. Bike would eventually stall on rides, he had to stop and open the tank to let air in. Not sure if it applies to you though, just easy to check.

 

[motomania2007]

Friend has a Bandit where the tank would eventually run out of air. Since the bike was old he bought a V-Strom and dumped the bike. Bike would eventually stall on rides, he had to stop and open the tank to let air in. Not sure if it applies to you though, just easy to check.

Reviving a 10 year old thread...

Improperly vented tank can cause what your friend's bandit suffered

 

[elskipador]

I believe the reserve position on the petcock generally bypasses the vacuum operated aspect of the valve.

that is incorrect. the reserve has a shorter straw into the tank, but the valve is still vacuum operated.

 

[ST Guy]

Well, things keep changing. Thanks.

 

[RVFRick]

The bike started fine this morning having an uneventful start-up consisting of 5 minute warm-up before heading out. I rode 7 miles on freeway to meet-up point, filled-up and parked for morning greetings with everyone. After maybe 30 minutes it was kickstands up time. The mike started then almost immediately began to struggle. I was able to nurse it to idle for about 20 seconds and then she died. Flipped open gas cap to test venting theory but no go. I waved the group onward and tried a few things before calling AAA for a tow.

I checked battery for connection. All connections were tight. I checked two of the bowls for gas and both had plenty of fuel. I let the bike sit for maybe 30 minutes to cool down but still would not start. Choke or no choke. I tried for a while until I eventually discharged the battery.

I called a Undealership and RMC to get suggestions but both bowed out saying not really their kind of bike. Evolution was suggested so I called and decided to have her towed there where she rests until Tuesday when they can hopefully take a look. Early thoughts for attention are carbs, vents and petcock. I hope it's something simple.

 

[BillSmith]

Fuel filter.

 

[RVFRick]

Fuel filter.

Perhaps. I hope it's something as simple as this.

I was on the fence towing it home and troubleshooting myself. Reality says my time and skill set are limited and I really want a bike to ride during the holiday break. Towing it home, making no headway and then having to pay for another tow to the shop was unappealing. I hope the guys at Evolution can get me going.

I have a replacement petcock I am going to bring them tomorrow. I also have some new carb insulators somewhere. "Just" need to find them.

 

[bobl]

Fuel pumps for carbs only produce 2 to 4 psi to keep the carbs full. A gravity fed auxiliary tank can be used to go around the fuel pump to see if that's the problem. You can even hang the tank on the bars and ride around the block if you're careful.

 

[RVFRick]

UPDATE: Evolution reported diagnosis of failed fuel pump. Bench tested and no action when connected to power. She runs on of an aux fuel bottle. They ordered pump from Ventura, CA. Dead battery on charger and will hopefully recharge okay and pass load test.