bad coil?

[chollahan]

Anyone have a coil go bad on them?

 

I got some bad gas a week or so ago right after I sea foamed her. Erratic idle and ran like crap. Filled up with good gas and cleaned the carbs real good. Idle smoothed out, but when I get on it, or under load, it just doesn't feel like the power is what it was before. Oh yeah, changed the plugs too.

 

I hit the cruise the other morning and got the 5 blink code on my cruise control lights.

 

I have also been riding in quite a bit of rain with this Texas monsoon going on.

 

Anyone have any ideas or have had the same problem?

[Gearhead]

It would be pretty weird to have a bad coil kick in right after your problem with bad gas (I recommend Beano for this ). Much more likely that you still have a carb blockage. If it is ignition (which does happen more under load), it's more likely to be the plug wires than the coils.

 

Jeremy

[chollahan]

Well, i got to testin 3 of the 4 coils and wires, (still haven't found the fourth coil). All tested fine with the exception of the back left wire. It tested lower then normal resistance, 9.50 ohms.

 

How do you replace the wires? looks to me they are fastened to the coil and are all one piece?

[Gearhead]

Some coils have replacable wires, some have the wires as part of the coils. Not sure about yours.

 

You said one coils tested 9.5 ohms. Is that supposed to be K ohms? What is the spec, and what did the others test at?

 

Jeremy

[chollahan]

Yeah, k ohms. the others were in spec, it was that one that was below spec. normal is 10 - 14 or so.

[Gearhead]

IMHO, 9.5 K ohms is plenty close enough to 10 to be considered "in spec". I seriously doubt that as a problem.

 

Jeremy

[chollahan]

Ok, thanks. I am not very wise to the electronics world. I didn't know how close it could be off to still be considered ok.

 

I have since narrowed it down to either of the left side coils. I can smell a strong gas smell coming from the left pipe and a loss of power towards the upper end. went for a trip to fill up today and my milage has dropped by 10mpg!

 

I gotta find the coil up front on the left side. I have looked briefly but could nnot find it. the manual is not very specific. Any clues on where I should begin to look?

[Gearhead]

Well, since your problem started on the fuel side, I'd say it's probably still there. This is supported by the fuel smell, although a misfiring ignition would do that. Does the bike idle smoothly? If not, find the cylinder that is not firing by starting it cold, warm up for, oh, 20 seconds or so, and then carefully touch your head pipes - the one that's not hot is the culprit. Float level is one possibility. Have you checked the plugs?

 

Jeremy

[MAINEAC]

It's like deja vu all over again...I have the same problem... I've been in TX for a month... I got bad gas and bike was running rough... ran sea foam through it no improvement... brought it to a local shop to have the plugs changed and it was still skipping... they found the rt rear coil was bad... they said it had a lot of corrosion on it and tryed cleaning the contacts but it was bad... said it was still putting out spark but very weak... had to order a new coil $58.00 + overnight cuz I'm heading back to Maine on Sat.

[gibvel]

Stardbog has the same problem here at Fort Collins. If you've got a spare plug take the plug cap off the left rear cylinder and put it on the plug......does it spark? You can also unscrew the plug cap and see if you're getting spark from the wire to a ground. If you're getting spark from the wire to ground it may be the plug cap. If not, probably the coil.

 

Dan was not getting spark at the plug and only a very, very week spark from the wire to ground. Fortunately, he's getting a new coil and everything should be good.

 

Hope you get it fixed!!

[MAINEAC]

UPDATE ON MY COIL PROBLEM: The bike shop owner said the coils are backordered at Yamaha...But he also found out a V-Star coil is the same and he had a junk V-Star in the back and the coil was good... Cleared up the skipping problem and I saved on overnight shipping and he charged me $25 for the used coil... I thought the time was a little excessive 1 3/4 hours to replace the coil.. At least I'm straightened out and I'm heading back to Maine tomorrow.. I got a case of Heat Exhaustion here in Houston and have had a headache for 5 days now..

[Beau-Kat]

On my 2000, I had to remove all of the intake ducting coming from the filter pods to access the front left coil. It hangs upside down from the frame behind the top of the radiator and below the steering head. Kinda hard to even see without removing the intake plumbing. It was a pain to get it out. It would also be nicer if it had a bit longer plug wire.

[chollahan]

Well, here is the update on my problem. Had a strong smell of gas coming from left exhaust (narrows it down to left side). I tested coils and pulled plugs after riding for a bit. Back left plug was wet. Sure enough, when I finally got teh multimeter figured out, the back left secondary coil had gone bad. Got one ordered.

 

It can't get here quick enough!!!!!!

[chollahan]

Yep, just called and mine is back ordered too!

 

Does it matter if it came off of a 650 or 1100 vstar?

[chollahan]

Well, had my guy order me one from a vstar 1100. Got home, put it on and could tell right away that it was working. Took it out for a test run and it was great to have power again, felt something that felt like missing when I got on it, but it was very sporadic so i passed it off.

 

Rode to work the next day and it was good. Got back on that night to head home and as soon as I cranked it over I could tell something was wrong. Sure enough, after I got out to highway speed I tried the cruise and it flashed me the error code for a bad coil!!!!!!!!!!!!!!!!!

 

Stopped to check and make sure teh connectors diodn't come off, (unlike the venture coil, the vstar does not have a spade connector that is smaller than the other so I had to force it on one of the posts). Everything felt fine, rode it home on 3 cyl.

 

I am thinking it has to be a problem with one of the wire connectors? I would think there is no way this brand new OEM coil could go out in 50 miles!

 

I'm gonna check some more when I get home from work today, in the mean time, any ideas???????????????????