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Hey this is my first bike it’s a 87 rebel 250. So it starts up fine majority of the time but if I rev it either it shuts off or if it doesn’t shuts off the lights dim. So are those problems related or are they separate? This is probably a dumb question but it is my first motorcycle.
 

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Welcome to the forum

sounds like two separate problems..
By shuts off do you mean like the ignition switch is turned off
Or engine stumbles and dies as if running out of gas?

110785


Most check voltage at battery, above is 85-87 Honda Rebel test procedure.

Ignition/spark electronics are totally separate from charging/lighting/battery electrical systems..Rebel will run without a battery installed though it is hard on voltage regulator..

I've seen bad/marginal battery cause headlamp dimming upon increase of rpm..
Fully charge battery and have parts supply house perform load test on it..
 

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Welcome to the forum.

The really dumb questions are those we never ask. This forum is here to provide information and assistance to those that ask. Everyone here started out with zero knowledge, and most of what they know, they learned from others.

Are you using the fuel enrichment (choke) lever when starting? It's located on the left handlebar control. You engage the choke by pulling it toward the rider. Most, but not all, Rebels need some choke when starting. You can ride with the choke on and gradually push it completely off as the engine warms. Revving the engine when it needs choke will often kill it, as will trying to add choke once the engine is running. Most Rebels like 1/2 - 2/3 choke to begin with. Any more, or less, and the engine won't start. Set the choke, start the engine, let it warm for about 30 seconds, hop on and ride.

Any time the engine rpms drop, the headlight will dim somewhat.

Have you taken a basic rider training course?
 
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85 CMX 250C, 82 GW Remember that you are invisible, treat all others accordingly. Avoids Road RAGE!
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Nice to hear another person with the first generation Rebel(85-87). Chrome!
Sorry to hear you're having trouble. Ask away! We are very happy to help another rider. Soakedkarma's marginal battery idea sounds like a logical possibility to the issues you describe.
If you do replace the battery yourself, always keep a box of baking soda ready in case you spill acid on yourself or something else. It will neutralize the acid. Normally I mix about 2 tablespoons in a cup of water and have it ready in case I get some on myself.
 

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Either too rich or too lean can cause that same effect. Like flitecontrol asked are you using the choke / fuel enricher at all?
 

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Welcome to the forum.

The really dumb questions are those we never ask. This forum is here to provide information and assistance to those that ask. Everyone here started out with zero knowledge, and most of what they know, they learned from others.

Are you using the fuel enrichment (choke) lever when starting? It's located on the left handlebar control. You engage the choke by pulling it toward the rider. Most, but not all, Rebels need some choke when starting. You can ride with the choke on and gradually push it completely off as the engine warms. Revving the engine when it needs choke will often kill it, as will trying to add choke once the engine is running. Most Rebels like 1/2 - 2/3 choke to begin with. Any more, or less, and the engine won't start. Set the choke, start the engine, let it warm for about 30 seconds, hop on and ride.

Any time the engine rpms drop, the headlight will dim somewhat.

Have you taken a basic rider training course?
I’m glad I read your comment: if I understand you correctly, the choke is “choking” when it’s in the downward position, and will start to ‘kill’ the motor if you give it throttle?
My buddy just rebuilt the carb, and showed me how it starts doing just what the original post stated, but he had the choke lever in the downward position. So it should run fine when we push the lever back up to the upward position?
The writing on the controls are so faded on this little 06 250 Rebel, that I just had to guess. I’ve put new plugs, air filter, fuel petcock(filter), battery… and such, and I couldn’t even get it to start. Since he rebuilt the carb with the kit I got from the dealer we can at least get it to idle… I hope this is a simple fix if we just let it run in the upward position…
 

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It's "choking" when the lever is pulled toward the rider. Most Rebels need choke to start, but it should be gradually pushed off as the engine warms. Most Rebels require around 1/2 to 2/3 choke to start. Any more, or less, and it usually won't start. Trying to increase choke once the engine starts usually kills the engine. Once it starts, you should be able to hop on and ride after waiting a few seconds for the oil to circulate. If the engine has to have the choke on after its warmed up, it's most often a sign the carb isn't clean. there should be no need to use the throttle when starting.

Hope this helps.
 
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It's "choking" when the lever is pulled toward the rider. Most Rebels need choke to start, but it should be gradually pushed off as the engine warms. Most Rebels require around 1/2 to 2/3 choke to start. Any more, or less, and it usually won't start. Trying to increase choke once the engine starts usually kills the engine. Once it starts, you should be able to hop on and ride after waiting a few seconds for the oil to circulate. If the engine has to have the choke on after its warmed up, it's most often a sign the carb isn't clean. there should be no need to use the throttle when starting.

Hope this helps.
I hope it does… we were able to start it with the lever toward the rider, and when we gave it gas it started to die-out. So when we start it and have the lever in the upward position - it should fun just fine?
 

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If it is cold, it'll probably need a little choke. About 30 seconds idling that way, you should be able to ride. After about 1-3 minutes of riding, slowly reducing choke,it should be completely pushed away from rider.
 

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^^^ What he said.

If it doesn't run well without choke once it's warm, there's a problem.
 

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On a cold engine, I usually pull the choke about 1/4 to 1/2, then I crank the throttle twice to actually spray some gasoline in the intake. Then I crank it and it starts almost immediately.
 

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So when we start it and have the lever in the upward position - it should fun just fine?
short answer Yes.. pushing the lever away from rider closes the enricher/choke
While some literature calls it a choke in other Honda literature it's an enricher/enrichment/bystarter valve.. Image below gleaned from Honda Common Service Manual which goes into greater depth of systems design..

I've never had to use enricher/choke when temperatures above 50°F to start bike..
Needing to use enricher/choke is an indication slow/idle jet fuel circuit may be partially or fully restricted

110839
 
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Next Question: we tried the suggested start-up procedure, and let it warm up with the enrichment (choke) and slowly eased the lever away from the rider, and it idles just fine.
Once again - when the accelerator is engaged the engine acts like it’s running out of fuel. I called the dealership and the service manager thinks it could be the accelerator pump. Wouldn’t this have been done during the carb rebuild?
Is this something that has to be done by removing the carb again? (or can it be done while on the bike?)
Or… is there anything else it could be that we aren’t thinking of?
 

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I'm not too good with carbs yet. But, your problem definitely sounds like the accelerator pump to me.
Please do a search on "accelerator pump" in the search bar above. You will see others with this problem & how it was solved.
 
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@jdskully
Accelerator pump from dealer is only available for 2nd generation Rebel 96-2016..
when dealers replace the accel pump the base with check ball is replaced along with diaphragm and is an extra charge
DIAPHRAGM SET, PUMP 16021-KEN-620 $86.03

Those of us with 1st gen Rebels have to adapt an available diaphragm to fit our application,, base w/check ball is obsolete..

you can check how well pump is outputting by observing fuel squirting out while pressing down on diaphragm shaft..
it's a short squirt, a stuck check ball can cause pressure to be forced back into float bowl.. cleaning should have solved that though..
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I talked with the dealership - this is a problem that is beyond my abilities... since the owner of the dealership is a long-time friend - I had his 'guy' meet me where I had the bike (and the other guy who'd been working with me on this) and we took my bike down to the dealer's shop. his head mechanic took a quick look at it and said our problem wasn't going to be as bad as I'd previously thought. knowing that this "other guy" had tore into the carb and used the rebuild kit I purchased from the dealership - he said that this other guy didn't clean some of the air intake ports, and jets as well as he should have. They said it shouldn't be a costly fix for me - and that they'd have this little bike on the road before I know it.
I was able to do a lot of the things to clean it up (plugs, air filter, oil change, brakes, new battery, and such...) but getting the carb in shape was a little more than I've done before.
I really do appreciate all the help you guys have given - but this "other guy" who'd been helping me was getting upset with me because he didn't want someone like me telling him how to work on motorcycle carb's...
I've learned a valuable lesson - in which - you guys pegged some of the problems without even seeing the bike, and someone I'd trusted wasn't even able to figure it out.
I tried to avoid the cost of going to the dealer, but sometimes I need to do what's best for the bike, and swallow my pride - and open my check-book (lol)
Even though they assured me this problem wasn't going to be too bad - my original fears of an expensive service call held me back from going to the experts.
You guys are all great - and again - thank you for chiming in with all the advice... what I've learned from you has given me a knowledge base that will certainly help me for the future. :)
Thank You - Jack...
 
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