300ex starting issue

[Stickman400]

Hey guys, I'm trying to fix a buddies 300ex and he had no clue what was wrong with it. But when I got it I hooked it up to the battery charger because my friend said it was dead. Well after I left it for a full day and it still was not charged I turned the key on and the neutral light would flash for just a second every 5 seconds, it was like it was on a timer or something, very weird. But when I unplugged the charger it wouldn't even flash, it just acted like the battery was completely dead. So does anyone have a clue where to start? I'm usually pretty good at diagnosing problems on my 400, but I'm not too familiar with a 300 and I've never seen a problem like this before.

[smr]

sounds like you should start with a new battery.

[rooster300ex]

Tighten everything elec. wise. Put a new fuse in it, umm see if it turns over my crossing the silinoid with a quarter or something. Pull the clutch in and try to turn it over. There could also be some loose wires were the reverse and neutral lights are etc. If it still does the samething after tightening everything get a new battery. It's pretty much the same as the 400 just looks different. good luck

[jweidner]

I would start with taking the battery out of the 400 and put it in the 300. If the 300 starts, problem solved. If it doesn't start at least you the battery is good and you can look else where.

[Stickman400]

Well I just went out and bought a new battery for it earlier. My buddy said it was weak and needed replaced anyway. It's charging over night so I'll put it on tomorrow and see if it fixes it, if not then I'll start checking and tracing wires, yippee.:rolleyes: Thanks guys.

[Stickman400]

Well the battery fixed the neutral light issue. I don't know why a crappy battery would have caused that kind of issue but none the less it's fixed. But now it won't start, acts like its not getting fuel. Tank is full of gas, petcock is on, kill switch is off, it's getting spark, but the plug looks black and fouled so I'm gunna buy a new plug and see if that fixes it, if not then it looks like I'll be tearing into the carb and cleaning it.

[Stickman400]

Well I picked up a plug for it and I guess it didn't even have the right plug in it. it had a DPR7EA and they gave me something else that Honda called for. Idk what that was all about but it still didn't start, just kept cranking over and over and had the occasional sputter that turned in to nothing. I'm gunna try starter fluid and pull starting it tomorrow, see if that does anything.

[buddy willard]

Originally posted by Stickman400
Well the battery fixed the neutral light issue. I don't know why a crappy battery would have caused that kind of issue but none the less it's fixed. But now it won't start, acts like its not getting fuel. Tank is full of gas, petcock is on, kill switch is off, it's getting spark, but the plug looks black and fouled so I'm gunna buy a new plug and see if that fixes it, if not then it looks like I'll be tearing into the carb and cleaning it. kill switch should be in on position, not off!

[Stickman400]

Well it's in the middle part on the stock headlight/starter switch, I call that off.

[Stickman400]

Well I got it to start after pull starting it, but it was more of a sputter than starting. It acted like it had a really bad vacuum leak, because it kept coughing and choking acting like it was sucking in either too much or not enough air and it wouldn't hold a solid idle. I'm gunna tear the plastic off and see if there is an air leak some where and then tear into the carb. Does anyone happen to know what the stock jetting is and the a/f screw setting on the 300? It's bone stock right now.

[smr]

While you have the pastic off check your valves. Tight valves will cause that problem. That should be at .004 inch.

Heres what you need to look for. Check your boot from the airbox to carb and also your intake boot. That is a real likely sorce of your problem.

Then check your valves. I would also check the timing chain while I was at it. You do that by loosening the adjuster, if it pops out then you still have tensoin. It must be reinstalled properly.

[Stickman400]

Well I think I found the problem. I took the plastic cover off the side of the carb that covers the throttle cable and everything and saw that the accelerator pump arm that contacts the throttle roller has about a 1/4" or more of play in it. It doesn't even come close to contacting the actual accelerator pump arm, it has about a 1/16" gap between the two even at WOT. I'm not sure what is causing it, the bolt that holds the the whole assembly on is tight, it's almost like it was bent or something. Idk if I can replace the pump arm or if I should buy a new carb, it'd prolly be cheaper than trying to fix the problem. Thoughts?

[smr]

you know what..I left something out.

Check your needle in your carb. I bet it's dropped. I can't believe I didn't think of that first.

as for your pump arm...I don't think thats your problem.

[Stickman400]

I'll be sure to check the needle, but wouldn't the accelerator pump arm cause it to sputter because it's not getting the extra fuel that the pump provides?

[smr]

not to the extreme you are talking about. That pump does very little.

By rereading your post I really think it's the needle.

Do you know the easy way to check it? If it did drop you should put it in the middle position.

[Stickman400]

Hmmm, I'll check it tomorrow. Idk what you mean by "dropped" but I could still see the needle move up and down in the carb when I moved the throttle.

[Stickman400]

Well I tore into the carb and checked the needle, it was still in the 3rd notch and looked fine. I took off the bowl and checked the jets, 122 main and 38 pilot. The main was clear but the pilot had a piece of dirt in the end. I tried blowing it out and cleaning it but I still couldn't manage to see through it so I'm just gunna pick up a new one. I still don't know what effect that accelerator pump being broken will have, but I'll slap the carb and tank back on and see if that pilot fixes the issue.

[Stickman400]

Ok, do you guys recommend putting in a 42 pilot over the stock 38 for cold starts like us 400 guys do? Or is the 38 good enough?

[smr]

now near the issue as the 400. 38 is fine.

let me now how this turns out.

did you ever check the valves?

[Stickman400]

Yea, I adjusted them earlier. The intake side was a little tight, but the exhaust was perfect.

[smr]

sounds like you know what your doing. For some reason it's always the intake the tightens up first.

Since you have it apart even thuogh nothing is in it I would still soak the main jet in carb cleaner. Even a little varnish will change things.

[Stickman400]

I've been reading a few of the jetting threads in here and see that everyone recommends running a 40 pilot when you upgrade your exhaust. I just ordered a new 38 pilot yesterday but am also putting a Big Gun Evo Race full system on it. Is the 40 pilot needed? Or just suggested? I'm still an amateur when it comes to jetting. I know when to re-jet, but can't really recommend jets to use.

[smr]

I dont' think it's that big of a deal but when we raced 300's we always upgraded to the 400ex carb. it's a cheap upgrade and does wonders.

[Stickman400]

Well I got it running. The pilot must've been it. I got that pilot in and the carb. back together and tried starting it and realized the fuel wasn't on after about a minute of cranking. Then after another minute of cranking I decided it didn't fix it and hooked the battery charger up to it and went to pull the plug and clean it and saw the plug wire was off. I plugged that back on and it fired up the milli-second that I hit the starter button, literally. Kind of funny.

[Stickman400]

Ok, I'm putting a Big Gun full exhaust on the 300 and leaving the rest bone stock. So for the jetting I'm thinking of just bumping the main up 2 sizes to a 128 or 130 and leaving the 38 pilot in. Does that sound about right for just an exhaust? I may lower the clip on the needle once if it gets a stumble to it, but I think it will be fine.