1986 Honda Rebel 250 dies while riding

[SanFranciscoRebel]

Hey all,

I just got this bike and started riding to work. I was having such a blast. And then, this morning I got to work and realized I had ridden the whole way with the shutoff valve set to the RES position. So I put it on "off" and went on my way. Then when I got back to my bike to ride home, the damn thing died while I was warming it up with the choke on and the shutoff valve set to "ON" as it usually is when I'm riding. So I started it back up again and it died again. The only way I could get home was to ride with the valve set to RES. I tried to take off the shutoff valve to clean it or something(I have no clue what I'm doing) and fuel got everywhere, so I put it right back on. I tried to ride it again after that and it starts up just fine the first time, but while I'm riding it will die, but first it's as if the more gas I give it the more it wants to die, but if i give just the right amount I can keep going. But as soon as I stop it's dead again, even on "RES". What the hell do I do? I'd really rather fix this myself as I don't have the money to go to a shop and the bike was only 800 to start with.

Bless you if you can help me.

[GearJammer]

http://houseofmotorcycles.bikebandit.com/honda-motorcycle-cmx250c-rebel-1986/o/m10724

Welcome aboard, SanFranciscoRebel......The link above should show the gas tank and petcock for your Reb.

When the petcock is in the "On" position, fuel enters from a higher point in the gas tank. When you switch it to "Res", the fuel enters from a lower point in the same stem........If the fuel level in the tank drops below the opening in the stem for fuel feed to the petcock, no fuel can reach the opening, which is why we then switch to "Res" so's the fuel can reach the lower opening.

You may either be low on fuel in the tank or the petcock may need cleaning to remove particles which are blocking either the "On" or "Res" access options in the stem.

The easiest way to remove & clean the petcock is to remove the gas tank from the bike entirely. Once off, lean the gas tank so the petcock is on the high side and/or have a receptacle under the petcock before you remove the petcock to safely catch any fuel that might drain out.

Once the petcock is out of the tank, you can remove the fuel bowl of the petcock from the bottom & clean out the screen in there. You can also remove the switch knob for "On"/"Off"/"Reserve" by unscrewing the 2 small screws holding it on. Carefully disassemble that section remembering the order for reassembly. Clean off any particles of sediment that you find. There should also be a cloverleaf looking neoprene washer behind there & you want to remember the exact position that was in because it has to be reinstalled in exactly the same way it was as this also has to do with the "On" & "Res" flow for normal usage.

Also check to insure that the flow-thru stem/tube is clean & clear of any obstructions.

Reassemble everything, reinstall the petcock in the gas tank.....you should be good to go.

Edit: Bike Bandit has changed their schematics........Just scroll down in the upper box until you see the "fuel tank" & then click on that to enlarge the view.......

[SanFranciscoRebel]

I like the fact that you guys take the time to share this stuff. I knew there were good folks out there!

If I'm low on fuel (which, believe me, is not impossible) then I deserved the embarassment of stalling out in downtown San Francisco at rush hour. Taught me the value of keeping full.

If that doesn't fix it completely, then I'm going to try exactly what you suggested as it sounds logical to me. I like the picture. When I pulled it (the petcock assembly)out I noticed there was a long stem. So, the whole mechanism is starting to make sense as far as function.


What do you think of this?

http://faqs.org/qa/qa-256.html

And, what was the effect of riding on RES the entire way to work? Is that even harmful if it's just gas going to the same place? I'm thinking maybe that lower entry is only meant to be used temporarily in the RES position.

THANKYOU!!

[GearJammer]

When you pop the gas cap off, can you see fuel in there ? It may simply be real close to being out of gas, but it does sound possible that a petcock cleaning "might" be necessary. You could try putting 1 gallon of gas in, which would easily raise the level to where the "On" position should work & see if that does the trick.

If not, onto the next step of petcock cleaning......and in the diagram, you'll see that you may or may not have another filter screen which covers the stem (some don't seem to have these, tho' they're supposed to, but you can theoretically live without it if it isn't there).

As regards running on "Res", the main concern is that it's drawing fuel from the lower portion of the gas tank & can allow sediment from the bottom of the tank to clog the screens quicker. Another thing that you might consider doing is installing an in-line fuel filter between petcock & carb to catch any junk that might pass thru the petcock to snag it before it can get into the carb, which can cause clogged jets, etc.

Checked out that link & don't have a problem with what I read there......There's gravity feed petcocks (250 Rebs have these) & vacuum acuated (ain't sure about the spelling, LOL! "activated" works ;) )petcocks (450 Rebs have these) With gravity feed, fuel flows when the petcock is in the "On" or "Res" position. With vacuum acuated petcocks, fuel should only be allowed to flow when hitting the starter button & after fire-up, when the vacuum acuation kicks in. On older carbs that are primed by hand (there's a primer "tickler" on some older carbs), it's easier to flood a carb. In those applications (of usually older kickstart bikes), draining the float bowl & starting fresh is an option. I prefer the option of holding the throttle wide open while kicking down on the kicker of the chop to fire it up if it's gotten flooded......Holding the throttle open raises the slide inside the carb, which allows more air flow to try to help balance the mixture & usually works just fine......On your Reb, with a choke & gravity feed petcock, if it got flooded, I'd be inclined to turn the choke to the "choke OFF" position, crack the throttle & hit the starter button.

[SanFranciscoRebel]

Hey Gear Jammer,

You are awesome. Thanks. I got in the bike lane yesterday, rode in first gear, half throttle all the way (5 blocks) to the chevron. Filled that bad boy up, and lo and behold, it was still stalling out. As soon as I'd open up the throttle a little it would die down, but if i decelerated a little (reverse throttle) it would go. So anyway I did that for a while and then tried something. I turned the fuel valve to off, started her up and let her run in neutral til it was out of gas. Then I switched to on and rode her home ( thinking i was going to have to catch the bus that day ). When I got home something miraculous happened..and it just started working. After a round up and down the block to make sure, I made a b-line for downtown san francisco. My bike ran better than ever before. Giddyup.

My theory is there was some contaminated fuel or old fuel in there, since when i bought it it was sitting in a garage for 3 months. I filled it up once after I first bought it and this past time was the third time. Turns out third times a charm cause it runs fine now. Now I just have to deal with feeling inferior to bikes with bigger engines...but I paid a lot less.

Thank you, Sir or Mam or whatever.

[GearJammer]

You're very welcome, but I'm not sure if I actually helped solve your problem or not, LMAO!

Today's fuel can go stale in about a month, so it's definitely possible that there was some stale fuel inside the tank. It's also possible that there was & quite probably is some funky residue inside the carb from fuel that sat, then evaporated, leaving the residue. It's ALSO "possible", LOL! that fresh fuel freed up some residue that clogged the carb jets, or at least temporarily, and that residue "might" have gotten run thru & out, eliminating the problem. (Lot of possibles here)

I'm a firm believer in "if it ain't broke, don't fix it", so if all is well & continues to be well, then keep on truckin'! ;)

If you do nothing else for the time being, I'd definitely recommend installing an inline fuel filter. Any indie shop should carry a variety of them, one being a clear conically tapered style, for around $2 (these come in 2 different sizes & the small one is ideal for your application). Just cut the fuel line at a good spot somewhere between the petcock & the carb, install the inline fuel filter and secure each end of the fuel line to the filter with those worm-gear hose clamps.

Once you've got an inline fuel filter on there, you could then pour a can of SeaFoam (available at most auto parts chain stores for approx. $7 per can) into the gas tank. SeaFoam helps to clean the carb while the bike is running as long as the carb isn't really gunked up.

Worst case scenario & IF the problem returns ? I'd remove & clean the gas tank, petcock & the carb........If you don't have one yet, a Clymer's Manual for your Reb would be worth scoring as it'll help you with a lot of useful info.

Ride Safe.......

[GearJammer]

Couple more thoughts here.......

You mention that too much throttle causes stalling, rolling off the throttle allows it to run better. This might be either a venting problem, an air restriction problem, or both.

If you click on the Bike Bandit link again & then the diagram for "Air Cleaner"......you might need to either clean or replace the air filter element (Part #3). If it's dirty/clogged, it can be restricting the needed air supply for the proper air/fuel mixture, especially when more fuel is being supplied.

You'll also see Parts #13 & 14, which is the charcoal cannister/seperator.....Unspent fumes from the combustion chamber of the motor are re-circulated into this cannister & back thru the carb. You'll notice a hose below the cannister with a plug (Part #20). That plug is supposed to be periodically removed to drain some REAL funky build-up from that hose....it's a mixture of fumes, oil mist, etc. & can cause venting problems when too full. Many of us have found that it's best to remove that plug & LEAVE IT OUT. The motor will breathe better, the hose won't get clogged anymore, it's just better all the way around.

Also, you may have another venting hose beneath the gas tank somewhere, which are common on California models. I believe the same goes for that hose......disconnect it from the EPA loop & leave it disconnected.