Page 2 - Chinese Go Kart ProblemsA Look at Some More of the Many Chinese Go Kart Problems I Encountered
(PLEASE NOTE: I cut and paste some of the communication I had with the company where I purchased this Chinese go kart. Therefore, it is written from that perspective - communicating directly with the company. Keep that in mind as you read it.)
UPDATE: NOW KART ENGINE HAS NO SPARK & WON'T RUN! I've been waiting for my parts to arrive to adjust carburetor jetting, but I've taken some test rides as it is even though it's not running totally right yet. Carburetor tuning should fix that. Yesterday I was out test driving in one of the fields at our farm for probably 10 minutes when all of a sudden, the kart engine died out in the middle of the field. Was driving fine and all of a sudden just died. WHAT NOW?!?!
My initial thought was: "ran out of gas??" I didn't think so because it was filled up and the kart has only been driven a matter of minutes! Checked it anyway. Of course, it was not out of gas because the tank was still full. After unsuccessfully trying to re-start it in the field for a several minutes, I hiked back up to the shop and got my other kart, a tow strap, and my son to help steer the 250cc kart. I towed the 250cc kart back up to the shop. That was all on Thursday evening.
Today, on Friday I began troubleshooting to find out why the kart engine died and would not restart. I was a bit suspicious of the carburetors just because of my previous problems with them, and I also wondered if maybe the spark plugs were fouled because I had been playing with the choke while driving to temporarily richen the mixture. I changed to new spark plugs (original ones looked fine - not fouled - but I changed them anyway) and that did nothing. Then I discovered something that eliminated the carburetors and fuel system as the culprit... that the engine has no spark at either cylinder. One of the first things that came to mind was a defective CDI module. I have no good way of testing this CDI module, so I began trying to eliminate other possibilities in the ignition system. I began checking the wiring harness for loose connectors, shorted out wires, bad ground, fuse, or anything that might be causing the ignition system to be dead. I checked the ignition switch even though it was behaving properly (the rest of the kart has power when ignition is ON - lights work and electric starter turns over when starter button pushed). I kept searching and searching and there was no obvious sign of any problem with the wiring that I could find.
To narrow things down further, I even removed the side engine cover to check out the CDI flywheel trigger magnet and pickup unit. It was a long shot, but I have heard of cases where a flywheel on a new Chinese engine had come loose (flywheel nut/bolt not properly tightened at factory) and the loose flywheel started to wobble and wreck stuff around it. I did not expect this to be it, because there was no signs of this and no noise from engine while it was running (or while cranking) that would indicate this happened. Nevertheless, just to eliminate another possibility, I removed the cover and inspected this. Everything looks just fine with the CDI trigger magnet and pickup unit - as I would expect on a brand new engine. The engine cranks over normally, but just can not start/run because there is no spark. Below are some pictures of my troubleshooting the ignition switch and CDI flywheel magnet and pickup.
I am including these pictures just to show you that I have been actively troubleshooting this latest problem, so that when I inconvenience you and ask you to send me another CDI module to test, you'll know that I have been greatly inconvenienced myself and spent a lot of time checking out other these areas before I ask you to do this. It's almost unbelievable that I am encountering another problem of a serious nature (dead engine - no spark) on a brand new engine! I say "almost unbelievable", because I have no choice but to believe it!! I've never seen anything quite like this - I've seen some tricky problems to troubleshoot in the past, but on this kart it has been one thing after another (and another and another...). Again, I'm not being mean spirited towards you, but just sharing the facts. It has been very frustrating. Sometimes, when it rains, it pours! I hope it stops pouring soon!!!
By process of elimination, I can not help but suspect that the CDI module might be defective and somehow went bad when I was out driving in the field. I do not believe it could be the ignition coils because there are 2 separate ignition coils (1 per cylinder) and the likelihood of BOTH coils going bad at exactly the same time would be a very far stretch in terms of probability! The next logical step is to try another CDI module. That's why I am sharing all this with you so you can see that I'm not asking to send me another CDI module to test without first troubleshooting other obvious areas. I've probably spent around 3 hours working on this NO SPARK problem so far, and I do not want to start unwrapping/untaping the enclosed parts of the wiring harness on the kart and mangling the wiring harness until after checking the CDI module. The picture below shows what I need.
Please send another CDI module that I can test as soon as possible. It can be a new one or the used module from your test kart... either way. I just need to try another unit. If after installing the different CDI module the kart runs, then that's the end of this troubleshooting episode. If the kart engine still does not run, then I will have to start digging deeper into the wiring harness to see where the problem might be. I've checked the harness and connectors that are exposed, but I have not wanted to take the harness apart and unwrap it or cut off the harness wire covers/sheathing because I don't think that is the problem. I don't want to mangle the wiring harness for no reason. Probability seems to point to the CDI module, but I won't know for sure unless I try another one. May not be it, but need to give it a shot. If that's not it, then I'll promptly turn back around and ship back the CDI right back to you... and then start scratching my head as to what in the world is going on here!
UPDATE - NO SPARK PROBLEM SOLVED. I discovered the mysterious source of the NO SPARK problem. While I was working on the buggy, I noticed that one of the electrical connectors on one of the coils was broken. Because it was still held together by the insulating sheath, it looked normal and was not something that was easily seen. I just ran across this while working on something else! The cause of this problem was once again because of faulty assembly in the factory. The electrical components were crammed together and mounted along one of the rear subframe tubes. The CDI module was bouncing around banging against the coil connectors on one of the ignition coils. Eventually, one connector broke. The CDI was crammed against the coil because the rectifier and other wiring were crammed against it. Since the rectifier was poorly mounted and just hanging there and banging into the shock springs, I relocated it. See pictures below. Now the engine is running properly. I have adjusted jetting and the engines runs MUCH better now.
Just when I think that my Chinese go kart problems might be coming to an end, then new problems surface! Click the following link to see a page showing more about the lack of quality control on Chinese go karts: PAGE 3 - CHINESE GO KART QUALITY.
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