Unfinished Business 5 – An Expensive Problem

Strange Problem

During the time when I was working on the bike’s various issues, I only rode short distances with it. The main reason was that we were all working from home due to COVID 19. Hence it took about a month or so before something strange started to occur.

On one of my rides to get to know the bike, I was coming to a stop at a junction when the bike suddenly cut out. The LCD monitor showed “CHEC” and pushing the start button turned the starter but the engine did not fire up. All the engine noises sounded normal but she just refused to start. The “CHEC” on the LCD was coming on and off. The first time it happened, I switched on and off the kill switch. Somehow that helped to remove the “CHEC” and the bike started up after that.

Kill Switch?

I thought that it might have been corroded kill switch’s contacts. Early Sunday morning, I took my tool box and opened up the kill switch assembly to take a look, but it looked very clean. Since it was apart, I cleaned it using light sand paper and contact cleaner and put it back together. However, this did not really help the situation as the bike still cut off without warning after that.

Another time it happened was when I was on the second lane of the highway and starting to accelerate. Suddenly, there was a loud “boom!”, “bang!” and I thought that my engine blew up! The engine cut off and the “CHEC” came up again on the LCD.

I switched on my hazard lights and coasted safely to the shoulder of the highway. Luckily (or not?) it was the same problem again and my engine did not blow up. There was probably some unburnt fuel vapour in the exhaust system when the ignition suddenly cut out and the hot exhaust pipe ignited them. The bang sure gave me fright! Just imagine if that happened when I was leaned over in a corner. Ouch…

Another time, I was returning from having breakfast with friends and the bike cut out 4 times along the way. Turning the kill switch on and off did not help. I even had to unplug the ECU and reconnect it to start the bike. and it still died after some time down the road.


So the kill switch was not the culprit but could it be the contacts in the other switches?

Another Sunday and another trouble shooting session. I lifted the tank, removed the airbox and traced the wiring. Having found the connector, I disconnected it, cleaned it when the contact cleaner and put a dab of dielectric grease into it. Since I had the tank up, I proceeded to find as many connectors as possible and did the same to them.

While I was doing this, I did not think that the connectors were the problem as they were all nice and clean just like the kill switch. Overall, the bike’s internals do look like one that had only seen about 54,000 km of usage.

The problem with this way of trouble shooting was that one never knows if one has solved the problem. The problem only surfaced intermittently. I can only know that it has been solved when it never happens again. Hence, the only think I could do was to ride the bike and see if the engine cut out again.

Other Switches?

Well, she did cut out again! This time, I took out the manual again, looked around and found this:

From page 4-15 of the manual

So I was on the right track. Now I needed to find the side stand switch and see if that was the problem. I tried zip tying the side stand switch but it did not hold very well. The little stem kept sticking out. I found a small piece of metal in a tool box and used it to hold the stem in with zip ties. It was better but not by much.

There was also a tip over sensor that I had to look for. By this time I was quite tired and did not want to continue troubleshooting so I gave a call to my mechanic’s shop and arranged for a tow to their shop.

They tested all the cut off switches and disabled them to narrowed down the possibilities. Their best guess was that the ECU had turned faulty. The fault was intermittent and that was what made it difficult to pin point the problem. When removing the ECU initially, one of the set of pins and connectors were filthy and corroded.

The corroded contacts of the ECU – especially the right side contacts and connector

After cleaning them, it seemed that they have fixed the problem, so I rode the bike back without incident. However, during the next Sunday, the problem surfaced again so another tow to the shop. This time, they were quite sure that they ECU was faulty and recommended that I buy a new ECU.

The ECU?

As these ECUs are very expensive, I asked if I could borrow someone else’s to try. It so happens that there was another exact same model at the workshop. I asked if I could borrow the ECU to test on my bike. The owner kindly agreed to lend me his ECU and my mechanic took it out. On unplugging it, the contacts were also corroded and in worse condition than mine. He put some WD40 and used compressed gas on it but it did not seem to make a difference. One thing to note is not to use any force on these contacts as it is VERY easy to break them. So please be careful!

I rode the bike around for a week to check and also went on a round island ride of about 200km. There were no cut outs over the 250km+ that I rode but once I put back my ECU, the bike cut out after 20 to 30 minutes of riding. So the villain was been identified!

I looked around Ebay and was disappointed to find that the used ECUs from all other GSXR models except the K3 and K4 were much more reasonable ranging from US$150 to US$250. For some reason, the K3 and K4 ones were asking for US$400-US$600. This was ridiculous!

So after discussing with the mechanic, I bit the bullet and ordered a brand new ECU. That cost about SGD$1200. Ouch! However, considering the price that I bought the bike for, I suppose it was still considered not too bad overall.

Incidentally, on the annual vehicle inspection, I went to the certifying office with documents for the after market exhaust to register it under my name (which will be in another update), the person there informed me that my bike had been laid up for a few years during her lifespan.

That made me wonder if the ECU fault was the reason. I guess that previous owners must have encountered the problem but could not figure out the cause or was not willing to pay for a new ECU? I guess I was sold a lemon this time as well, but thank God that it turned out that I was able to make lemonade this time!

In the next installment, I will be talking about the most time consuming part (at least for me) of getting the GSXR right – the Convertibars, riding position and the black hole of suspension settings.

3 thoughts on “Unfinished Business 5 – An Expensive Problem

  1. Hey it’s me again

    Thought I left a comment but it didn’t show up. Hope you get it all sorted soon.

    Anyway I was gonna ask you if you’ve had the chance to ride both K4 and K5/6? I’ve sat on both and the K4 felt a bit bulkier but also cramped leg wise and a stretch to the bars. But it could be the aftermarket rearsets on that one I sat on.

    I’ve considering between a K4 ($7.5k) and a k6 ($11K-ish). Both 99% stock with similar mileage. Do you think the K6 is worth 4k more (2 years more COE)?

    Curious to know how much you got your K4 for. And what improvements you got from the bar risers/pegs if any.

    My email is below if you rather not reply here.


    1. Hi hi, sure let me reply you in detail via email.

      Yes, you are right. From the K1/K2 to K3/K4 to K5/K6, the physical size of the bikes get smaller and actually better for Asian builds I believe.

      I have not ridden the K5/K6 but it has become somewhat of a “cult” bike due to the long stroke engine (from what I read), so folks might be trying to sell it a higher prices. Hmm…as for prices, I think bike prices in Singapore are ridiculous, thanks to our dear garmen’s taxes, so I might never ever be able to buy anything new.

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