350x problems

[Dammit!]

I'm having issues with my 350x (again). Most likely electrical. Carb is cleaned out real good. Jetting is a little lean but not bad enough to cause much more than some popping on deceleration. The bike is mostly stock except for a supertrapp. Jetting is at stock settings. Airbox lid is on. Elevation around 1100 feet.

The thing just keeps cutting out. Sometimes just for a second. Enough to make it stumble, pop, then come back to life. Other times it just dies out completely. I have video to show exactly what it's doing but won't be able to cut it together until tomorrow night.

I found that the spark plug cap was not firmly attached to the plug wire the other day and thought that was the source of the problems but even after screwing it on there nice and tight, it's still doing it.

Assuming it is just randomly losing spark, what are the components to take a close look at? Kill switch, coil, ground wire, what else?

It also seems to have lost some compression today out of nowhere. Not smoking or anything. Still ran fine when it did run. Not sure what the hell is up with that. Valve adjustment maybe? I normally have to jump up and use all my weight to give this thing a good kick. Now it's kicking over easily, like the decompression started working correctly all of a sudden. The lever is not moving though so that's not it. What can cause a compression loss without any smoke or loss of power?

I'm getting tempted to just fix it and sell the damn thing.

2-STROKES FOR LIFE! :lol:

[big yeller]

my 110 did the same thing then one day it died and wouldnt start. it needed a new coil. it wouldnt hurt it to adjust the valves.

[Dammit!]

Bump for the 350x gurus.

[Dirtcrasher]

It can't hurt to adjust the valves..... I can't see the decomp. hangin up though, unless the cable did it, but that would be right from the get go.

I would probably check all wiring connections and put some dielectric grease in them.

The kill switch won't do this. You can unlug thaqt whole harness (lights and all) and it will start and run, just not shut off. The 2 off positions are to ground it out, thats all...........

Once you check all the connectors and the system grounds (there may only be 1 or 2) it will give you a chance to look at the overall condition of the harness.

If ANY of it has electrical tape on it, remove and inspect it. Then just re-tape it with clean hands and clean the harness with carb cleaner, alcohol etc etc; So that the tape sticks.

Not much to a 350X so it won't take you to long. Many times it's what someone else did to your harness, those abusers!! :D

[Dammit!]

I already know the wiring is a mess. Kill switch housing is a little cracked up so I was wondering if maybe it was randomly grounding it out. That's exactly how it acts when it dies. Like it was just shut off. I'll unplug it just to see. Whatever is causing it has been getting progressively worse over time.

Could a valve adjustment cause a decrease in compression like that? I forgot to check the header bolts before I went to work today. I was thinking about that as I went to sleep last night. I had that happen on the 200x before and it seemed to make it kick easier.

Any other ideas what could cause these symptoms? I like to be loaded up with things to look at before I dive in. I can't think of anything that would cause it to act like this other than electrical but then again, I'm not much of a 4-stroke guy so...

Edit: Before the Gordons Well ride, I put a voltage regulator off a 1985 250r on there. I don't see how that could be part of the problem but, could it? That and the new lights were new for that ride. Man I'd love to just completely re-do ALL the wiring on this thing...

Edit #2: You know what's REALLY aggrivating about this? It NEVER acts up in the driveway or on my street. :mad:

[Dirtcrasher]

Doug, you can unplug the whole lightswitch, that eliminates it as an issue with grounding in there.

I PROMISE, it will still run without it but you'll have to kill it by popping the clutch or whatever......

As for the decompression, I'd remove the cable and see how it acts, If it acts up, then it could still be an issue within the head. Other than that there could be a stuck ring or a valve that isn't always seating. Who knows??..................

I hate RANDOM failures, they're hard to figure out! Just break already!!

DC

EDIT - We gotta get you a crate motor :beer

[Dammit!]

EDIT - We gotta get you a crate motor :beer

That might be overkill. The motor has always ran strong. It's everything attached to it that seems to give me problems.

I've had little annoying problems with this thing since I got it. Previous owner issues mostly. Once I get all of the little half assed things re-done whole assed it should be fine. :lol:

[3Razors]

Elect issues are some of the most annoying problems. Does it only do this when the bike gets hot? Could be a few things, small break in the coil wire, cdi/stator getting old and acting up. If the wiring harness looks rigged from the po def look that over. And valves that are too tight will def cause loss of compression. I could also bring over another good running 350X to try and swap over elect components if we need to.

[Mr_RPM]

sounds like an ignition coil to me, if it was a stator it would fail then never run again. but also like u and DC were saying, probe around for connection problems. do u have a multi meter to test around with? find a bad ground or something. but yeah coils have done that to me in the past. good luck i hate electrical stuff lol

[Dammit!]

Jason, thanks for the offer. I'll let you know once I dig into it a little. I might have a line on some cheap parts. I need to know if they'll work though.

Can somebody tell me for 100% certain if the following parts are swappable between 1985 and 1986? My trike a 1986 but these parts would be off a 1985.

Wiring harness

Coil

Voltage Regulator

CDI

Thanks.

[devilman]

according to bike bandit, everything is the same for 85/86 parts you listed.

[RapidRick]

Mine was running crappy about a year ago, almost the same problems.

I ran down everything, checked every wire run and component with meters and finally changed the CDI.

Runs fine now.

Maybe weak spark = feels like low compression.

Hope this helps.

[harryredtrike]

Elect issues are some of the most annoying problems. Does it only do this when the bike gets hot? Could be a few things, small break in the coil wire, cdi/stator getting old and acting up. If the wiring harness looks rigged from the po def look that over. And valves that are too tight will def cause loss of compression. I could also bring over another good running 350X to try and swap over elect components if we need to.

i agree here^^^^^^after you rule the grounding problem

[Dammit!]

Still haven't had time to mess with it yet. After work last night I pulled on the pipe just to see if it was loose. Felt tight. Started it up a couple times (with sneakers on which I usually can't do without hurting my foot). Starts easy when cold. Doesn't seem to screw up unless there's a load on the engine so revving it in the garage won't do anything. HOPEFULLY I'll be able to mess with it some this weekend.

I was thinking about revving it up and hitting different parts of the wiring with the hose and see if it shorts out. Might be a quicker way to figure out where the problem is. Especially given that it usually won't screw up at the house.

Any thoughts on that 250r voltage regulator possibly causing issues? 12 volts is 12 volts so I don't see how but who knows.

[Dirtcrasher]

The regulator only affects the lights.............

I wouldn't garden hose it, I would wiggle crap around while running.

If you didn't inspect the harness and use dielectric grease on there 1st, I don't know what to tell you other than I have never seen a bad CDI. I've seen plenty of bad stators or coils hen they get hot though...............

[jensenracing77]

i have never seen a bad 350X CDI but i have seen a bad wire going into the CDI. i seen more than one get frayed right at the plug and do what you are talking about. (well not the compression part) to tell you the truth, i have ben around 100s and 100s of hondas and never seen a coil go bad. i have seen people change them but it not be the problem but just never seen one bad. i'm not saying they can't go bad but i don't think i would look there first.

[Russell 350X]

I would check every inch of wire on that harness, check the coil with a meter, and adjust the valves. I've never checked a stator with a meter, never had a problem with one, but I would imagine it's very easy. I can't think of anything else that it could be.

[big yeller]

my 110 coil was bad and my 70 coil is bad. check both coils with a fluke 189 multi meter, resistance values was off. also like stated before i had seen a coil once it gets hot it will act strange or completely quit.

[gearjock]

try putting a heat gun to the coil to get it hot and see it the bike starts acting up but make sure you dont melt the coil

[Dirtcrasher]

Gearjock - I LIKE that idea! never thought about that and the OHMS could be tested cold and then after it was heated up......

Jensen - THANK YOU!! I'm so tired (and I do feel bad too) that people become "PARTS CHANGERS". There is nothing wrong with borrowing a buds coil or CDI to see if that could be the issue, but, especially with Honda, I rarely see CDI's or coils go bad. Most of the time it's a bad connection (LISTEN TO RUSSELL) and sometimes when you guys swap parts, you jiggle it around just enough to get it working again, even if the suspect part was AOK from the get-go................

Doug, you said your not ready to throw in the towel and try to snag a crate motor YET.......; And I respect that decision...... If it isn't smoking like helll and the clutch/gears are good, then there is no need for a crate motor ( I just like them :D ) I agree with above as far as checking the entire wiring harness (every inch - remove that tape!) and all of the connectors. I always squash back down those female spade connectors with some line mans pliers.

Good luck!
DC

[RodKnockRacing]

ive seen a bad CDI if it was bad it would run fine at an idle but would fall on its face at full throttle just something to check too

[3wheeledjunkie]

If something is grounding out wrong, you'll feel it when it zaps you to the beat of the engine running. Figured out my 110 had a break in the tailight wiring this way.

[3Razors]

When it comes to electrical don't count out anything especially on 20+ year old bikes. I've seen some real hair puller issues with components that test out fine with ohm meters but when running or hot give quirks. At that point last resort comes to swapping out with known good parts.

[427]

My 86 350x started running all crazy one day. One time it would run ok and after you would kill it it would run like it was out of time. Went to dealer and got a new cdi box. Dealer said they either work or dont. It totally fixed my problem.

[Dammit!]

I haven't had a chance to mess with it at all yet. Hopefully this weekend.

I was gonna snipe a coil and nice wiring harness last night but totally spaced. They went super cheap too. Sucks because I really wanted that wire harness and it sold for two dollars.

[beets442]

Have you done a compression check,(cracked ring?)It'll still run but no power....Beets

[jensenracing77]

a little off topic but want to put my two cents in on this CDI unit stuff. i have not had a bad CDI on a 350X but i have had a 4 bad ones over the years on other bikes. there is a misconception that a CDI will work or it won't. well yes it could be bad that way also. i had 2 go bad that would just quit (and not caused by heat) sometime they would run and sometime they would not and cold or hot. another way is like mentioned above, it will idle fine but not rev, like the rev limiter was cutting out early. and the other way i seen one bad was that it would rev but would not advance the timing causing it to not have very good power on top.

[atckowalski]

This happened to me too. On my 350x it would randomly cut out if you hit a bump just right. It turned out to be a fractured wire inside the factory harness which looked fine from the outside, but it was still touching except for it randomly cutting out. So check that. About the trading Cdi boxes out, Its is probably the connection to the cdi box, not the box itself.

[Dirtcrasher]

^Yep! Just as another example back in 1999, my 250SX would randomly blubber/cut out and I must have cleaned that carb 10 TIMES!!

Then I said, it can't be fuel and it has to be electrical. So I started inspecting the harness and on a 250SX, the CDI is on the battery box which pivots a little bit wit the swingarm.......

I found broken and frayed wires under the factory electrical tape right at the CDI. Had I not removed the tape, I may have been one of those knuckleheads that replace the on/off switch, key switch, coil, stator, CDI and so on. I had to get new pin connectors and crimp them in, then install them into the female plug.

Especially with Honda, many times it's something REAL EASY your overlooking. I think when people get dead set on one thing (like I did thinking - FUEL!) it's hard to open your mind towards other possibilities................

[Dammit!]

Messed with it just a tiny bit today. Started it up and started grabbing and moving wires. No effect. Didn't get shocked either. In the next couple days I'm going to try the heat gun trick. I'll heat up the coil and the CDI. Hopefully that reproduces the problem. I found my spare CDI tonight too so one less thing I have to worry about there.

This has been going on for a while but not as bad. I always thought it was fuel related unil recently. Check this vid out. You can hear it cut out at the one minute mark. Imagine that but much worse and you'll have an idea what it's doing now. Maybe hearing it will give someone an idea. I'm planning on checking the timing, valve adjustment and the decompression gizmo. I have a hunch it's the decompression that's causing the compression loss. When you kick it, the lever by the kicker doesn't move. After I figure all that out I still have to wrestle the broken footpeg bolt out. Those are always fun. :lol:


http://www.youtube.com/watch?v=0944zU-OOTk

[boosted96cobra]

Another forum member has been having this same issue. he said he messed with it a bit and it only does it with the fuel on the "ON" position, with it on "RES" it is fine. Liek something is clogging the petcock. Maybe something you can check to see if it is a fuel problem.

[Dammit!]

I started doing that months ago. Doesn't seem to make a difference. Fuel flows out the petcock fine. Carb doesn't seem to be plugged up.

[Dammit!]

Well I think it's all fixed now.

I tried jiggling all the wires again today. No effect the first time. Tried hitting it with water while it was running. No effect. Tried the heat gun on the CDI and the coil. The coil didn't do anything but the idle got higher when I heated up the CDI but it never cut out or anything. Tried one last time messing with the wires and this time (after it was warmed up from the heat gun) when I moved the CDI box it instantly died and wouldn't start. You could tell it wasn't even getting a spark. Moved the CDI again, started right back up. Messed with it some more while it was idling and got it to cough and sputter when I was messing with the wires right by where it plugs into the CDI. Unwrapped all the electrical tape expecting to find a broken wire. Nothing. Messed with it some more while it was idling with all the tape off expecting to get shocked. Nothing. Pinched the wires up by the connector again and it coughed.

I think what's going on is right inside the CDI there's a cracked solder connection. When it gets hot from the nearby exhaust pipe, it's expanding, causing it to randomly cut out. I replaced the CDI with the spare I found last night, repeated the tests and nothing. That little off idle dead spot that it's always had even seems to be gone.

Fixed the footpeg too. I used to think there was nothing more irritating than a broken bolt. Now I know there is something more irritating. Breaking off an EZ out when you're trying to fix the bugger. :mad:

I loosened up the decompression cable. Seems like it got some of the compression back. It still starts up easy, sounds fine, still has good power. No smoke or weird noises. I'll investigate that further another day. I'm spent. :lol:

Test ride coming as soon as possible.

[Vealmonkey]

I'm glad to see you're getting a handle on this. I know you dig your trike and I've been following this thread to see what the problem might be. All the best on your test ride. Thanks for the update on your find.

[p26575r16]

Glad to hear you got it ironed out. There are a lot of things that could cause that issue. For example, my 350x was brought up to Wyoming (when I lived there) from St. Louis by my friend. He had ridden it all week before bringing it up and it ran great. When it got to me we went out for a quick ride and it ran exactly like yours was in the vid, except it would die when it started cutting out. My x was in almost showroom condition, never butchered up. I knew I'd have to re jet it (st. louis 400 feet above sea level, Wyoming was about 6000 where I lived) but I thought there could be no way jetting would cause it to die like that. He brought up his 200 big red (from st. louis as well) and it ran good, so it could not be jetting, right? I'd change the plug and get about 15 minutes out of it before it would start acting up again. I chased everything down on it and nothing seemed to work. I finally got irritated enough to try jetting it leaner and see what happened. After jetting it leaner I never had another issue with it. Just goes to show you the weirdest things can cause weird issues on one bike but the same setup might work for another. As far as the decomp lever is concerned, I took my cable off and locked the lever in the off position because I kept having it stick on mine. I am not really sure why Honda thought it was neccessary on that engine, I am running 12.5:1 compression now and I don't have a problem starting it.

[jeopardy98]

I know I'm late to this party but I had an old 84 Suzuki dirtbike that had the exact symptoms you described and ended up tracing it back to my cdi as well. When it would die I would smack it with my hand real hard a few times and it would run again for an hour or so and then I would smack it again and on and on. I finally ended up finding one on ebay and replaced it. I never had another problem.

[Dammit!]

Just wanted to update this thread. It was definitely the CDI. It's running fine now (even in the rain) since swapping it out. I disconnected/reconnected the old one to make sure it wasn't just a bad connection so I'm sure that old one was the culprit. Still don't know what caused it to start kicking so much easier all of a sudden. The decompression is clearly not functioning. I'll have to tear into it at some point to figure out what's going on in there. Doesn't really seem to be having any effect on the way it runs though.