Vibration! A cure for bad vibrations, Spark Plug Caps!!

buzzbomb said:

Yep R1 coils would also work. Only ones to avoid would be the earlier R6 coils which were CDI, and have a lower primary resistance. You'll be looking for something with a primary resistance around 1.19 to 1.61, so when it's wired up in series it'll be closer to what the ECU is used to seeing, and won't cause any issues with the transistors. MT07, MT09, FJR1300 and R1 coils are safe, but if you can find out the primary resistance then you'll know for sure if it's suitable.. Not sure about other brands.

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buzzbomb said:

Hi everyone,

Firstly a disclaimer- Don't try this mod, it's still experimental and if you try it and your bike breaks down then I'm not responsible!

I've been working on a project on my bike, which was suffering from vibes for a long time. I had tried working on cutting the leads back, which worked kinda sorta, but not that well. Then I tried replacing the leads with some newer HT leads, but the issue was getting a reliable connection on the coil end. I had looked at the idea of Coil on Plug, and read a lot online about other bikes where owners had swapped their wasted spark coils for a wasted spark COP setup. There is a thread on an FJ1300 forum which details the conversion, as do several others, but many forums have been crippled by the whole Photobucket debacle which has made it hard to find detailed photos.
I decided to buy 2 COPs from a Yamaha fz07, just to try and see they'd fit. I found they fitted nicely from the top with the tank and airbox removed. I then ordered two more from a Yamaha FJ1300 from ebay and also a wiring harness from a Kwaka Z750. I stripped the wiring out of the loom and rewired it in series. Coils 1 and 4 were wired in series for one coil connector, and coils 2 and 3 were wired in for the other connector. Primary resistance went up from stock values of 1.53-2.07ohms to around 2.5. I checked the original coils and they were really low (out of spec) so that could have been the cause of my vibes, combined with the HT leads.
Anyway here are a few shots.
View attachment 69428
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The bike fired up straight away once I finished the wiring and put everything back together. I ran the bike in the shed for a while then took it for a ride today and was impressed with the results. It ran cleanly through the rev range without any issues and the vibrations were gone. I could have easily picked up a second hand set of coils off ebay but I wanted to try something different and move away from HT leads altogether. From a technical point of view I was concerned if the coils would still fire the plugs cleanly at higher revs as the coils are firing twice as often in the wasted spark setup compared to the bikes they were designed for ( FZ07 and FJR1300) but the coils haven't had any dramas so far. I made up a wiring loom with spade connectors to plug straight into the factory loom. I looked at the option of wiring the coils in parallel but that would require a 1ohm resistor to pull the resistance back to what the ECU is expecting, so there isn't anything to be gained, in fact I did some calculations and worked out I'd have less power at the coils.
Anyway as mentioned it's still an experiment but so far the bike feels great with hardly any vibes in the 6k upwards rev range.
Enjoy...

Buzzbomb.

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Super0Rudk0 said:

I had problems with my coils (after 20 minutes of highway I lost 1st and 4th cylinder, worked again when cooled off) so I tried the COP conversion since even my spark plug caps looked off. I bought 4 cheap COPs for R6, I checked the resistances and all matched and put them into my bike. The bike ran flawlessly when started. No vibrations and quiet. I took it for a ride and didn't find any problems, but after few minutes it stalled on me once I stopped. Then it was stalling 5 seconds after starting the engine again. I had a little bit of problem to start moving again, but once I was moving everything worked flawlessly. I raised the idle to 1400rpm and It was managing to stay on most of the time, but the idle was incosistent when warm (flawless when cold). I changed the oil, fuel filter, adjusted CO values but nothing helped. I swapped the old coils back and the misfire dissapeared.

I took a gamble on cheap COPs and lost, but at least now I know how to dissaseble the bike.

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1. Cam chain/CCT wear, mechanic showed me how chain has ~5mm of play between cam shaft sprockets. Said it's okay for now but should be replaced next year, together with CCT.
2. That I somehow messed up TBS, despite setting all 4 cylinders at ~21-22 cmHG at idle ~1300RPM
3. That coils/contact are somehow still bad despite measuring on spec.
4. That TPS is bad. It only goes up to 90, but smoothly without any other issues.
5. That engine mounts are bad. Previous owner installed sliders upper rear engine mounts, and bolts have right thread pitch but not exactly right depth: 41 & 36 instead of ~45 OEM. I don't know how well it can be seen on this picture, but 10mm bolts also sit in 12mm frame hole, there's a ~1mm gap around bolts. I didn't know if it was supposed to be like this, so I've inserted aluminum washers/sleeve to size. The mounting points of frame that go to the engine also look really bad. They're spot welded in only 2-3 places and I can stick a paper under them. Not sure if this is normal.
   

Gary in NJ said:

What are your compression values for each cylinder?

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