Need help figuring out stalling concern. When running at high rpms engine would cut out, like losing 1000 rpms? Imagine flipping the key off and on is what it felt like. No power loss or smoking. Was 20 miles down trail when it started. Then when trying to diagnose it stalled out completely. Unable to pull start, wanted to fire but sounded like starter was staying engaged. Help!!!

 

I joined this forum because I thought youm Honda guys might be smarter than other forums I have seen. No ideas?????

 

while i'm not a honda guy, or a guru by ANY means,
if the ignition stutters, & won't go any more rpm, THAT sounds
like the rev limiter. I hit it all the time in my street bike.

as far as the rest of it, I don't know wnough to make a educated guess
I have had older model dirt bikes not fire when they got hot
becuase the ignition broke bown (Husky 430, with sem ignition)
the only cure for that one was motoplat ignition.

so it could be an ignition problem, if you have not changed anything..
I'd probally start my diagnosing there..the starter hanging up, could be related, or
could just be a peice wore out..
see if it does it when it is cold, then when hot, you may want to check to see how much spark you have in these instances.

just throwing out ideas..probally get a better answer from the others.

 

Starter hardly turns over fast enough now. I never had this problem before, have had atv for 5 years. My buddy has same setup and his does not do this. I know its not the rev limiter because I am familiar with that kicking in, this will do at 3/4 throtlle and above.

 

well..again, assuming everything is fine, (by that I mean that bike was not rejetted recently,) had valves adjusted(IF 4 STROKE) float level in carbs is ok, ignition circut fine, plugs gapped correct, all maintenance done, air filter clean, oil changed, cables lubricated, choke not sticking, carbs not gummed up, needle not out of the carb slide, fuel petcock not stopped up, etc.. etc... sounds like something is wearing out.
(gee, I know that this is no help)

I'll admit that I know NOTHING about a 300 ex, never even saw one, 2 months ago never even owned a quad, but I have 2 street bikes in the shed, a prarie, & had 4 dirtbikes in previous years..

I'm quickly running out of ideas..

I have had ignition problems, fuel problems, rejet tweaking, & valve adjust issues before, but about the only thing that happens "out of the blue, with no warning", is either ignition problems, or the needle in the fuel bowl sticks & you arn't getting enough fuel, both of these feel diffrent, & will give you a place to start.
maybe better to defer to the others who DO know about this model, as my info is more general in nature.

 

I am still lean toward possible electrical or ignition problem. I would not think that carb would do this intermently and then stall bike out commpletely. At first I thought it was fuel, since it happened after we filled up but no other quad had problem in our group. Fuel was since replaced with fresh fuel and same concern? I was the 1st to fuel though? Can the ignition module do this and then quit working altoghter?

 

well,
the ONLY experience I had with that on a bike was on the 84 Husky..
the ignition got hot & stopped working, it wouldn't even fire
nothing going to the plug..when it cooled off it would start..
it got so bad that the bike quit from the garage to the end of the driveway..
usually this happens on older bikes/trucks more often than newer ones
95% of the time, carbs, valves, & other things WILL give warning, & not be intermittent.

ignition will not always follow this..sometimes it will, sometimes it won't, usually when it happens,
it gets worse over time & especially with heat & run time. I have had some stop dead, & had to be replaced, other times it gave a little warning.. (rotor button on a gm/hei was DOA at one time & left me stranded) other time a ford ignition module broke down after getting hot when it cooled off, I limped back home, time above it was the husky..

 

You need to start with ,does it have fire to the spk plug?Does it get gas to the carb?Was the charging system charging the battery ok before?check these things & let us know.Daryl

 

Hey, truck brand new plug in it, oil been change - all maintenance always kept up. Battery was low when I 1st tried to start it, had to charge battery due to winter storage, once started battery stayed up enough to restart on every ride. Plus on a 300ex as long as the battery is hooked up they will run. Even if the battery is completely dead, although you would have to pull start everytime. Also replaced sparkplug after problem occurred. Old plug showed normal burn. I even removed sparkplug boot and short sparkplug wire by 1/4 inch to improve connection. Oil at proper level and clean. K&N filter clean, air box clean and same jetting as prior 4 years without change.

 

<< When running at high rpms engine would cut out, like losing 1000 rpms? Imagine flipping the key off and on is what it felt like.
Then when trying to diagnose it stalled out completely. Unable to pull start, wanted to fire but sounded like starter was staying engaged. >>



my guess would probably be that your carb needs a new needle valve. i had a very similar problem with my YZ.
if it really is the electrical you might want to check the battery, ignition coil, stator and cdi; frist check all of your connections and test the wiring for shorts. since honda intercanges their parts alot you might be able to take the the cdi off of your 400ex and test it on the 300. or if you have a friend with a 300ex you could use his electrical parts to find the culprit. be aware that doing this could potentially ruin the borrowed part. check your voltages and be careful. happy hunting.