Quantcast
Jump to content

Recommended Posts

Posted

I would check that cylinder for loose connection at the coil or corrosion and replace the spark plug. Bad CDIs do not usually have intermittant spark, they either work or dont work.

Posted

Have you done any preliminary diagnostic work, such as checking for spark on the miss-firing cylinder ? Checking whether that cylinder's plug is getting wet or if it's dry when it's miss-firing ? Most injectors vibrate when they are firing, if you put a finger on it you might detect one not going properly.

And, have you noticed any circumstances that seem to cause the problem, such as wet weather, after it gets hot, only on a cold start, after a certain amount of time regardless of load ?

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Forum Topics

    • By neilroy87
      I have a 1990 Bayou 220 that runs pretty well for it's age--needs a new muffler, but sounds tough.    Have had to start with a pull cord since I got it, and recently started troubleshooting the start button.  Finding a lot of information on this issue in the forum, but haven't been able to chase it down yet.  Got a new battery, new starter solenoid, and going to replace the starter relay this week, but not convinced that's going to do the trick, since I can't get the neutral light on when turning the key on.  I can start it by jumping the solenoid, but the 2 black wires to the relay do not activate the starter.  Bad ground or a short somewhere?  Is there a good way to just test the ground?
    • By carkivey3
      i just picked this up. was told ran fine but overheating issues led to replacing head gasket and head. has not ran since. he is not a mechanic but helped someone else who he could not get back to finish job, got aggravated and put up for sale. i was thinking timing issues. i have 110-120psi on all 3 cylinders so i think valves are correct. dont know about distributor yet. however i have no spark. i have no power going to ignition coil. tried to follow white wire but gets lost in wire harness. does anyone have a wiring diagram? can anyone tell me what conditions have to be met before starting. motor turns over so i would think all safeties are met but you never know.
    • By P_syko
      Hello all! I’m new to the 4 wheeler world, but not new to the mechanic world. I was a diesel mechanic for many years and last year got into jet skis. I just bought a 1987 Yamaha moto 4 350 and now learning the ins and outs of 2 stroke engines. Looking forward to learning all the things. 
    • By Snick
      Bought the project a few weeks ago with weak and intermittent spark. I could smack the CDI box with a screwdriver and it would work fine for a few days. Now, the smack trick is not working and machine is running awful with the weak spark and will most often not fire enough to turn the engine over through combustion (cranks very good). I ordered the GY6 CDI to see if I can get it going again as these CDI boxes are way too expensive even used. battery is fully charged and charging very good.
       
      Wondering if anyone knows how the GY6 (6-pin AC) CDI would wire to this machine. Attached is the electrical diagram. My confusion is with the green and orange wires sharing the 2-pin connector and the Blk/Red wire that runs to the magneto solo. How would I get AC power to the CDI through pin 1 on the GY6 when the CDI has two wires to the pickup-myabe just try one (orange then green) at a time?
       
       
       


       
      ^PINOUT:
            5   6
            2   4
           1    3
    • By KdlH
      Hello.
      I'm new to the forum, I live in the UK. I have just bought a 1995 Yamaha Moto 4 350.
      Generally the condition isn't too bad (I paid very little for it!), it looks quite original and all the plastics are quite good. The bad bits are no brakes, the rear axle bearings are shot and the transmission won't shift through the gears properly.
      I'm not planning on a full rebuild but I would like to sort it out a bit. The transmission is my main concern. If anyone has any ideas on what might be the cause I would be grateful. I can explain what's happening in more detail if required.
      Thanks everyone,
      Kester
       



×
×
  • Create New...