If I remember correctly, when I would catch my step-dad gone to work, and steal his '88 300, I could run it WOT on the road and it would rev till I backed off the throttle. Now I am older, and own a '96 300 4x4.... seems its a little lacking on the top end but I'm satisfied, problem is, running at 3/4 to WOT, after approx 15 seconds it will just quit... bogs down as if no spark or fuel. then it will pick up and run again... its like.... errrrrrrrrrrrrr bughhhhhhhhh..... errrrrrrrrrrrrrrrrrrrrrrrrrrrr bughhhhhhhhh..... runs fine down low,, runs all day... no inline filters, carb cleaned twice, petcock is open and clear.... does this cdi have a rev limiter?... is this my prob?...
starving for gas or CDI
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it feels like nothing , you would never know , unless you had two bikes one each way , and go take on ride on both then you can feel a difference ----for your 96 they offer a Rick's Unlimited CDI , but be careful there are fakes out there , buy it direct from Rick's over the phone if you got that route
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It is probably running out of fuel or the valves are too tight. It doesn't sound like an ignition problem or a rev limiter.
thought so... mine just shuts off like a light switch.. for couple seconds,, then turns back on... didn't think it was rev limiter.. as above it don't just go to say 6k rpms and not go higher... it shuts completely off like the key is turned off.. then it picks back up... i could "make" it do it.... just run it up to 6k,, shut off key till it slows to around 4k.. then turn key back on... exactly what it feels like its doing.... feels like it runs out of gas to me.. like the flow can't keep up with the usage... but my carb is clean...flow to carb is clean... i just don't know... unless the cdi is getting hot or something... humm.. wonder what my prob could be.. i searched everywhere I know to search online...
valves are not tight.. actually they are beginning to tick a little... this thing just turns off and comes back at near top speed... as long as I don't go beyond 1/2 to 5/8 throttle, it will run all day long,,,or i can go WOT for short bursts at a time with no prob.. but on the road, after about 20 seconds of 3/4 throttle.. it just decides to quit for 2 seconds.. then catch its breath and keep going..
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Could your vent on your gas cap be plugged. One time years ago I had the breather hose get pitched in the hole that it went into causing it to get vapor locked, it would run for awhile and then die, let sit alitte bit and it would start right back up. If I remember right the 300s had the vent in the gas cap that you could turn on and off so I don't know if that could happen to that stlye but I suppose it could still get plugged.
One thing you could try would be to hook up a timing light. You could observe it flashing at normal speeds, and then when you accelerate to high speed, and the engine cuts out, you could see if the light is still flashing or not. If it keeps flashing even as the engine is dying, you know that your ignition is working, and the problem is likely fuel starvation.
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Maybe you never cleaned the carb good enough the first two times , very common problem , I have cleaned carbs numerous times to get it right and have cleaned them numerous times and never did get it right and bought a new carb and all was well , how does your step dad feel about after market carbs from like China ?----did you clean it with a can of spray or do a soak in a gallon of cleaner and had compressed air to blow out the passages ---- you mentioned being a son of a Honda tech , surprised your looking for help
My father passed away 5 years ago... China carb? No way he would have went for that. Honda OEM or nothing. Carb is clean as a whistle.... clogged air vent wouldn't come and go, as I have had it accidentally turned off and once the vacuum created stops the flow of fuel, it won't run whatsoever... I have watched my father rebuild dozens of these engines, but I doubt I could without some google and videos.. He never was a fan of mud bogging, nor a fan of welding anything... He despised people that welded the shift lever onto the shaft, as many people did when their lever got loose. I have learned a lot from him, rest his soul. Yea if he was still alive I would't be on here... I tried contacting 1 of his work buddies, but can't find him anywhere. Wish I could find someone this has happened to. Next time I go out, ill try the timing light, if that don't work, ill try a new cdi box... such a strange symptom....
well.. plug tells me things are ok, but could use a new one... electrode is tan, with a little bit of heat transfer on the porcelain. electrode starting to round off around the edges just a tad... ive seen 300's run with worse for sure.
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Very sorry for you losing your Father , I know what you mean about his ways , my Dad was the same way , he was old school and it was his way or the highway
something easy to check , you don't even have to take off the carb , there are 4 small screws holding the cover on top the carb , under the cover is a diaphragm , if it had a hole or split in it , it will not rev up high speed , mine had a tear in it and would fall flat on it's face , don't know if this is your problem but would be easy to check it out
something easy to check , you don't even have to take off the carb , there are 4 small screws holding the cover on top the carb , under the cover is a diaphragm , if it had a hole or split in it , it will not rev up high speed , mine had a tear in it and would fall flat on it's face , don't know if this is your problem but would be easy to check it out
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I agree sounds like fuel starvation. Loss of flow or loss of vacuum at WOT.
You mentioned gas tank being clean but I want to make sure about the details. There’s a coarse screen above the petcock and a fine disk screen in the petcock body. You say the are both clean?
Fuel line straight from the petcock to the carb; no inline filter?
If yes, and you’re 100% on carb, clean the fuel cap, empty the spark arrestor plug.
The manual chap 22 says after all that could be a faulty CDI or pulse generator
Page 22-4
You mentioned gas tank being clean but I want to make sure about the details. There’s a coarse screen above the petcock and a fine disk screen in the petcock body. You say the are both clean?
Fuel line straight from the petcock to the carb; no inline filter?
If yes, and you’re 100% on carb, clean the fuel cap, empty the spark arrestor plug.
The manual chap 22 says after all that could be a faulty CDI or pulse generator
Page 22-4
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