Engine sound is not right no power

This bike only sat for 3 weeks then played up? It must be something simple....when running, are one or more of the headers cooler than the others?

 

I was dealing with the same issue every time I had to leave my bike sit while I was on the road for up to 2 weeks at a time. I used seafoam at 1oz/1 gal. It will clear up the mess from the fuel after 1, or 2 tanks. If you want a faster option. Pull the carbs, and shoot the passages with cleaner.

Merc.
Most of the big name suppliers (shell, marathon etc..) that carry top tier fuels limit the ethanol to the 87 octane. The off brand suppliers is where you need to watch out. And now with the new biofuel blends it will get even more fun. Diesels may run on corn oil. Gas engines do not.

Ghost

 

I will do a resistance test on the coils this weekend. I did not notice one of the headers being cooler than the others. I'll check. I drained the gas tank and put a high octain fuel in with StarTron. New inline fuel filter. Still no real power and off on the engine sound pitch. I guess I need to make a decision to try the Seafoam or pull the carbs and start cleaning again. If I run with the Seafoam for a tank or two I won't damage anything will I? Thanks for all your input.

 

Check the spark plug caps and be sure you don't have a loose resistor core (they screw in, inside the cap.)

Just for kicks, fit a BRAND NEW set of correct, properly-gapped spark plugs.

 

I checked the resistor cores in the plug caps. When I inspected the inside of each plug cap I only found two that had a slotted insert that must have been the resistor core. They were both loose so I tightened them. The plug caps that had the resistor core installed had a deeper boot then the other two without the cores. The two shorter booted plug caps without the cores did not have any threaded hole to install a resistor core. Is it installed in the wire connection farther up in the boot? Did not make a difference in performance after I did tighten the two cores. I did check the primary and secondary coil resistances. They were:

right coil - primary 2.5 ohms, secondary 22.7k ohms
left coil - primary 2.6 ohms, secondary 27.9k ohms

From the Yamaha manual it looks like the maximum resistance on the secondary was 13.2K ohms, so both are out of spec.

How can I get the colortune to work if the coils are out of spec?

I went to install new plugs and found #4 sooted up. #3 was not looking to good either.

So am I looking at new coils, wires, and plug caps along with pulling the carbs again for a cleaning?

 

The OE plug caps don't look the same there should be a pair of 'long' caps and a pair of 'short' caps, and they do not have any resistor higher up the wire. Sounds like a part swap, what kind of plugs are you using (resistor or no). Those are bad #'s on your coils secondary for sure-you did do the test from plug wire end to plug wire end with no caps attached right? If not repeat the test that way, but even so the higher resistance in your left coil suggests a problem.

With that much resistance they will still generate a visible spark, but that is usually all it is and not sufficient to ignite-the reason is the pressure they're under. When you pull the plug it doesn't have to fight 140psi air/fuel mix to spark, under Normal conditions it MUST be strong to ignite the mix. Good bet most of your problem is related to this. Your carbs might actually be ok and not need a new trip to the CoC.

Your primary resistance looks ok though so your issue could just be the wires. At this point, assuming those results are correct, you have two options, do surgery on your existing coils and hope that fixes it (basically fit new plug wires by splicing into the coil (note: if you are familiar with electronics this is not hard otherwise it is a hard job), or you can replace your coils, & wires and likely be good to go. Used is cheaper but no guarantee of quality, there are some new A.M. sets that will improve performance over stock.

 

I used the non OEM Dyna coils that chacal sells. But I also replaced all my caps.

 

I thought these were original coils, wires, and caps. There are two short and two long plug caps. Original Japanese company name on the caps. I think the long plug caps had the screw in resistor. Maybe it is just an adapter for the spark plug. I measured from inside each cap. That was what I saw in the Yamaha manual with the primary disconnected. How do these caps come off? It looks like a molded connection to the wire. If I can get the caps off I will take a measurement at the wire ends.

If you use the Dyna Coil you must come up with a new mounting scheme correct? You would also have to make up a connector on the primary side.

 

You didn't get a bad load of fuel by any chance? Water in tank?

 

I don't think it was a bad tank of gas. I think the bike sitting for 3 weeks just gummed up the fuel system. I don't know what I am going to do to store it this winter. I have run my 4th tank of high octane and StarTron through and it seems a little better response on the throttle. The engine evens sounds more like it should. The problem now is I pulled the plugs to take a look at them and #4 was black soot. Not oily. So with the coils out of spec and now I am fouling plugs I am just going to pull the carbs and go through them again. I am also going to look into some coils, plug caps, and wires.

 

Forget the high O it won't do any good and is totally not needed. If #4 is the only sooty one then your looking at dirty carbs, pilot mix is off, or a bad synch, or a combo-plus obviously your coil might be an issue as well. Be sure and double, maybe triple check things before you decide they are bad, I had a high idle I was sure was an air leak and I had just forgot to readjust my idle screw after doing the carbs.

As far as for winter you need to run good 89 octane with UCL (SeaFoam, StarTron, STP UCL) or similar through it and then either drain your bowls or leave em with the UCL's in and run it every week or so. You can also use fogging oil which will keep it corrosion/gunk free for months w/o running it.

I know this seems like a puzzle that just won't come together, but it will and once it does and your consistent with your maintenance and fuel issues you won't ever have this problem again. It's just a symptom of an old machine, bad fuel, and needed maintenance.

I started with a too lean 550 (were talking lilly white plugs and not able to idle in stop and go traffic w/o overheating), which progressed to missing at low rpm's and 35mpg, to now being spot on, tan plugs, 53mpg, and a 12.9sec 1/4mile-spec says top speed should be 113mph, I hit 117mph (at Hallett motor racing circuit, too paranoid to do it on the street) measured by GPS. I have smoked several 2000+ year model 600's with a 528cc based on 1981 technology, so hang in there--you can do it.