Gorka´s CFM 650 NK

I bought this bike with over 3.000 km on the clock. Although I am still waiting to get it plated (but that is a whole different story), I have ridden it and messed up with it (mostly) enough to share some notes.

The first thing I noticed after my first ride was that it was nearly out of coolant maybe half of it left. The issue about the loose hose clamps has been adressed well enough in other threads. The problema is now solved after simply tightening the screws, specially the one on bottom end of the hose on the left side. The good side is to think about all the time the bike must have been running like this without melting, very reassuring.
Attachment 13539

Screws and threads are easily damaged, like some people have noted. In my case, I found that one of the two screws that hold the contact lock had been sheared inside its location. It might be that this happened as somebody tried to steal the bike from its previous owner, I dont know. While some people recommend to change as many screws as posible (which I dont agree, as it is better to damage a screw than the insert or nut) I do recommend to replace these two, as it is more difficult to remove once broken. Luckily for me, I could remove it and replace it. I also replaced the lock, which was slightly damaged. Thanks Bikerdoc for the parts!
Attachment 13540

I also replaced the mirrors, which had too much play and didnt hold at legal (just about) speeds. I also placed new horns, BBS favourites.
Attachment 13541Attachment 13542

Another change I plan to do is the levers. My brake lever got notched and it was difficult to push down smoothly. Apparently, the soft aluminum was damaged by the edges of the holder. Maybe this was promoted by the loose screw. I was able to fix it with some fine sandpaper and after greasing, it is good for another few thousand kms.

Coming back to the leaks, I also found parasite air aspiration (or vacuum leak). I noticed the bike was rough and unstable on the first touch of the throttle, I could barely ride at 40 km/h in second gear without the bike stuttering. I found there were at least two spots of aspiration below the butterflies. One was (again) the loose clamps on the colector ports, and the second apparently the connection of the left vacuum hose to some short of manifold, below the battery case (anybody knows what that is for, anyway?) Instead of connecting directly to the manifold, it has a section made of thinner material (it feels more like a sleeve than a hose) and the clamp was very loose on it. Some rearragement of the clamps so they seat on the thicker material (where it is not deformed yet) plus some twisted some wire around it did the trick for me. After a reset of the ECU I can now stroll around town at 20 real smooth, which is way better for showing off. :mwink:


Cheers from Dagang, Tianjin province,
Gorka.

Thanks for sharing. Most of the issues with these bikes seem to come from the frame thread and bolt quality as well as loose factory parts.

HI Gorka

Good post the more we all hear about problems like yours the more we can all be better of with our own bikes. Thanks for posting I need to post about my water leak now .

By the way how do you reset the ecu?

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Originally Posted by ZMC888

By the way how do you reset the ecu?

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Hi Zmc888

I think you turn the key to the steering lock position and the to the off position .! but not 100% sure

Quote:

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Originally Posted by ZMC888

By the way how do you reset the ecu?

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You can reset the ecu by leaving the battery disconnected long enough. I do it by disconnecting the positive pole and putting it in contact with mass. That discharges the condenser that feeds temporarily the memory. It's a trick I learnt from my SUBARU (official) mechanic in Spain, with whom I shared a lot of experiences and time to debug a problem in my car.
I will post a pic later, can't do it from the phone.

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Originally Posted by gorka

You can reset the ecu by leaving the battery disconnected long enough. I do it by disconnecting the positive pole and putting it in contact with mass. That discharges the condenser that feeds temporarily the memory. It's a trick I learnt from my SUBARU (official) mechanic in Spain, with whom I shared a lot of experiences and time to debug a problem in my car.
I will post a pic later, can't do it from the phone.

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Great to know about the ECU re-set was not 100% because from the owners manual it did say

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This motorcycle is equipped with a vehicle-down sensor (also called roll-over sensor),
which causes the engine to stop automatically and the FI indicator to flash when the
motorcycle falls down. After righting the motorcycle, first turn the ignition key to the
“ ” position, then back to the“ ”p o sition before starting the engine.

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so was not sure

This is the spot where I reckon the the vacuum leak was coming from. In that section the hose is thin and he clamp doesnt fit so tight.

Who knows what is this manifold where the two vacuum hoses connect? Is the vacuum opening the fuel valve, is there any other function?
Attachment 13595

And this is how I reset my ECUs
Attachment 13596

Quote:

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Originally Posted by ZMC888

Thanks for sharing. Most of the issues with these bikes seem to come from the frame thread and bolt quality as well as loose factory parts.

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Thanks ZM.
I have seen your report too, I will give those screws and nuts a try too.

I used to reset the ECU on my Nissan Skyline just like that, I did it about 2 a month as the ecu would learn if any poor quality petrol had been run through the car and would lower boost pressure and retard the ignition. I wish I had that car here in China !