strange misfire at idle

[VsMaxx]

hey everyone, im having a very strange misfire at idle. it seems to do it only when im in traffic and the temp guage is about 3/4 of the way to hot. ive cleaned and synced the carbs, twice and im starting to think maybe i have an ignition box thats beign affected when its hot. it also sounds like its only the left cylinders cutting out. but it will clear up if i rev it up or get some air moving and cool it down.

thanks guys!

 

[SpecOps13]

You need a fan switch so you can turn the fan on at long lights....
Just don't leave the fan on when you're moving unless it's absolutely necessary...

 

[VsMaxx]

so your saying that misfire is normal when it gets hot?

 

[maleko89]

Next time it does this pull fan and headlight fuse and see if improves. Check charging volts @ battery too.

 

[VsMaxx]

ahh, good thinking maleko, i did notice last evening when it was running like crap, when i had the turn signal on, the highbeam indicator would dim. you guys think maybe the crimp fix is in order?

 

[maleko89]

Yep, crimp for sure if not already done. Also, clean and solder the connections from stator to R/R. Solder connection from R/R to main fuse too.

 

[SpecOps13]

Mark could very well be right. If your charging system is strained the ignition system may be the first to suffer...

 

[alorio1]

Check voltage at the battery at different RPMs, you are probably low on voltage from your charging system. When voltage gets low your bike will miss and stumble because you don't have enough voltage to supply CDI and coils with proper voltage, this is very noticeable when cooling fan comes on which taxes electrical system even more. I had to do the R1 rectifier mod to overcome the same problem you are having. Older Maxes have an insufficient charging system and has to be upgraded to the newer Rectifier by Yamaha or do the R1 mod which is the best of the two in my book. Check all your connections , especially grounds, and see if you can get charging system to put out more voltage.
__________________

 

[rollin thunder]

My Max sputters a little when it is cold and my 650 nighthawk was the same way.

 

[VsMaxx]

OK i know its been a while but i haven't quite still figured this out.
the bike was and still is deffinetly suffering in the charging department. I have done the crimp fix, R1 R/R, cleaned and soldered all the connections and i have also run a new 30A main power from the RR to the battery and one for a ground, all using 12ga wire.
My stator ohms out with all 3 legs at roughly 0.8ohms and, is putting out between 5-6v AC from each leg.
Now I am at about 13.5v at idle but when the fan comes on it drops down to about 12.1v-12.3v. at 3000 RPM im at about 13.8v with no load and at 12.6v with the fan on.
battery checks out good and it never accually drains down to the point where it struggles to start the bike. But when the fan kicks on ive got one hell of a misfire.

Its not unrideable but its embarrassing to sit at a light with this terrible misfire and then take off stumbling and running like crap untill the fan shuts off.

Any help guys? I appreciate all the advice on here!

Thanks a lot
Ryan

 

[bazwell]

Ryan, maybe load test the battery on it's own.
You could try putting your multimeter on the battery, with the key on but the engine not running. Then short the temp switch out so the fan comes on and see how low the volts drop.

Or, get the battery checked with a proper load tester.

 

[sdt354]

5-6 volts ac sounds too low. If all connections are good and clean, I think the stator is suspect. Fan on, you still should be in the mid 13's at least.
Steve

OK i know its been a while but i haven't quite still figured this out.
the bike was and still is deffinetly suffering in the charging department. I have done the crimp fix, R1 R/R, cleaned and soldered all the connections and i have also run a new 30A main power from the RR to the battery and one for a ground, all using 12ga wire.
My stator ohms out with all 3 legs at roughly 0.8ohms and, is putting out between 5-6v AC from each leg.
Now I am at about 13.5v at idle but when the fan comes on it drops down to about 12.1v-12.3v. at 3000 RPM im at about 13.8v with no load and at 12.6v with the fan on.
battery checks out good and it never accually drains down to the point where it struggles to start the bike. But when the fan kicks on ive got one hell of a misfire.

Its not unrideable but its embarrassing to sit at a light with this terrible misfire and then take off stumbling and running like crap untill the fan shuts off.

Any help guys? I appreciate all the advice on here!

Thanks a lot
Ryan

 

[VsMaxx]

5-6 volts ac sounds too low. If all connections are good and clean, I think the stator is suspect. Fan on, you still should be in the mid 13's at least.
Steve

thanks guys, i think im going to suspect the stator. the battery reads 13volts after sitting all night. fan on engine off the battery reads 12.2v

any stator better than another? will one from a venture work?

 

[sdt354]

I believe the Venture to have better output. There are also after market stators. Of course, you can contact the members here that have good used parts. I myself wouldn't spring for a stator from the Yamaha Steeler.
Steve

 

[Rhoy Carter]

The Ricks aftermarket stater is good and I think Sean Morley sells them

 

[VsMaxx]

What should the stator be putting out for volts? And what is the correct way to test for volts? I'm just back probing the connector with the pos lead and putting the neg to ground. Is this right or wrong?

 

[Miles Long]

What should the stator be putting out for volts? And what is the correct way to test for volts? I'm just back probing the connector with the pos lead and putting the neg to ground. Is this right or wrong?

Wrong.
Set your meter to A.C. volts. Negative probe does not go to ground. Black and red probes do not matter in this case. Measure the A.C. voltage between all three wires - i.e., A to B, B to C, A to C.
You should get around 20v at idle, this should steadily increase with rpm. You should read 50 - 60 v. at 5000 rpm. What is equally important is that the measurements are fairly consistent between the wires.
You should read Rawarrior's excellent article on charging problems and testing, found as a "stickie", I think in the Electrical forum. Follow the Electrosport Fault-finding chart.
Cheers!

 

[naughtyG]

You should get around 20v at idle, this should steadily increase with rpm. You should read 50 - 60 v. at 5000 rpm. What is equally important is that the measurements are fairly consistent between the wires.

Also note that if you get a reading of 70V or higher when you go up in revs your stator is prolly fried - that's what happened to mine when the 3-wire plug melted. It looked like it was charging when cold and revving on neutral, but after a while riding battery would be flat..

 

[VsMaxx]

Thanks guys I'm going to try some of this stuff today. I'll report back tonight.

 

[VsMaxx]

figured it out guys, stator is TOAST!! Measurements at idle are 19v, 21v, and 1.2v. guess shes seen better days. only went up to 4.2 volts at 3000 RPM.
Here's a question for you guys, when changing it out do you guys use new gaskets or just RTV the case?

thanks alot guys!