Topic: cb350 four cylinders 1(most left) and 4(most right) not firing

[Dos]

Hey guys it's been awhile since I've posted... I bought a cb350 four about 4 months ago with 7,000 miles. It ran beautifully and only needed an oil change... Then

I was riding it home and all of a sudden it clunked out on me. I couldn't get the bike up and running and it only started going if I held the throttle down if I let go it would stop and cylinders 3 and 4 were only firing. After wheeling it back home I did some diagnosing and I put new plugs and checked the current of the coils. Everything is good. Before the bike died I heard a lot of rattling like keys but that's its. If anyone could help I would greatly appreciate it and would be willing to pay money for services in the New Jersey region. 

[xtravbx]

Those cylinders coils are connected. Even though you said you checked current, I'd suspect the coils.

Also, you heard rattling? Hopefully you didn't spin a bearing. Drain the oil and look for metal.

[trueblue]

Sounds like you had a points failure, the rattling you heard would have been pinging as your timing changed with the point gap. 

[flybox1]

check your #1/4 point gap

[Davidov]

The points contacts will also wear out. If they are pitted or have slight corrosion from arcing, they will definately not work properly.

If you don't know when they were last replaced, it's probably time!

[TwoTired]

The regular service interval is 6 months/3000 miles.

Has this ever been done?  Do you have an owner's or shop manual?

[Dos]

Hey guys I looked at the points today they look good in my opinion ( however i am a novice)

here are some pics

[Dos]

Here are some pics the other one was blurry

[Dos]

I dont want to have to drain the oil to check for metal because it cost alot to put new oil in but I will if you guys really think metal is in there

[Vinhead1957]

The set that has both blue wires on it is the one that fires both 1&4. Check the point surface for signs of pitting. It could also be the bullet connector to the coil. Trace the wires back to the coils

[flybox1]

what is the 1/4 points gap?   
with your plugs out, rotate the big nut until the point is open its widest.....
It should be in the neighborhood of .014"
clean with an old business card sprayed with brake cleaner...
if its pitted, get a points file and carefully file it.  dont use anything else to file it.

[dave500]

I dont want to have to drain the oil to check for metal because it cost alot to put new oil in but I will if you guys really think metal is in there

umm,you can pour it back in if its clean.

[Dos]

Also when I hold down the throttle and the 2 cylinders are firing every 20 seconds or so it will start to sound like all the cylinders are catching for 5 seconds and then it stops

[flybox1]

The regular service interval is 6 months/3000 miles.

Has this ever been done?  Do you have an owner's or shop manual?

+1
time to start from the top 

[Dos]

Thank you guys for the inputs I'm going to check the points again.. Unfortunately I can't find any mechanic who will donate time to an old bike this like that needs servicing and when I do find one they charge way to much

[whizzer]

Had this happen after got cb350f, got home on two cylinders. Then a lot of forum reading. Took off plug caps and there was corrosion where cap point snugs into wire. Clipped off 1/4 inch to expose clean wire and reinstalled caps. Has not happened again. I was struggling with carbs at the time. So don't know for sure. But clipping wires was needed. 

[Dos]

This is the point for the 1 and 4 cylinders. There are no signs of pitting but is this gap to big? The other points gap is a little smaller.. I could just be second guessing myself .. This pic was taken at its widest. When I bought  the bike with 7000 miles new points were freshly installed

[Dos]

I'm inspecting the wire from the point's into the electric box area.. Maybe this could be a carb problem? Gas used to leak out of the very left carbs hose but only when it sat for awhile

[flybox1]

sounds like you have no tools, and or no desire to check or maintain on your own 

[Dos]

This is inside of the electric box everything seems to look okay. Unfortunately I don't have to many tools but I'm trying hard to fix this

[flybox1]

The regular service interval is 6 months/3000 miles.

Has this ever been done?  Do you have an owner's or shop manual?

+1
time to start from the top 

OK, SO....for the third time 

DOS, you're looking for one small fix, when you should be covering big ticket items like those listed on the maintenance schedule, which, when done properly, usually get a bike into running condition.  If they dont get you running, at least the forum knows the bike is in a proper state of tune, and then we can better troubleshoot for you.....

[Dos]

Good news! I started the bike up and the point with the blue wires is firing I see the sparks but the yellow and blue is not! Now I just have to make that connection work but idk what's wrong with the point there's nothing on it but it doesn't seem to open to much

[Dos]

Bike is in proper state of tune btw I checked the MOM

[flybox1]

Good news! I started the bike up and the point with the blue wires is firing I see the sparks but the yellow and blue is not! Now I just have to make that connection work but idk what's wrong with the point there's nothing on it but it doesn't seem to open to much

set that max point gap to .014"

[flybox1]

check that yellow wires crimp where it attaches to the point. 
it looks like its touching the points plate in one of the pictures above.    If it is, move it.