Misfire In Traffic

[Geordie]

Bike has UFO StreetPro 4into 2 fitted, even after tightening up exhausts etc it again started misfiring and has cut out when stuck in traffic for a while and temp gauge rises..standard carb / filter setup.

 

[sdt354]

Check the electrical system first. Nothing to loose. Battery sitting overnight without a charger, voltage of 12.5 minimum or ditch it for an AGM or suitable modern battery. Charging system, hot, at idle, fan on. Voltage of 13.5 minimum (off the top of my head). Lots of threads on the subject here.
Steve-o

 

[Geordie]

Thanks, it has a gel battery fitted. When it cuts out it does start easily and temperature doesn't enter Red zone.

 

[Dragmaxster]

Bike has UFO StreetPro 4into 2 fitted, even after tightening up exhausts etc it again started misfiring and has cut out when stuck in traffic for a while and temp gauge rises..standard carb / filter setup.

Geordie, it's is actually quite normal for these bikes to run a bit high on the temp gauge but if it starts running rough then I would suggest a "shotgun" procedure and maybe doing the manual fan switch mod.
If it smells hot then for sure that's not good.

 

[Geordie]

Geordie, it's is actually quite normal for these bikes to run a bit high on the temp gauge but if it starts running rough then I would suggest a "shotgun" procedure and maybe doing the manual fan switch mod.
If it smells hot then for sure that's not good.

No burning smell thankfully, and once traffic cleared it appears to get better.

 

[Dragmaxster]

No burning smell thankfully, and once traffic cleared it appears to get better.

That's usually what it does- have you seen the manual fan switch mod- pretty simple to do. Also this mod will cool it down.
http://www.vmaxforum.net/showthread.php?t=112&highlight=thermostat

 

[Irtron]

started misfiring and has cut out when stuck in traffic for a while and temp gauge rises.

I had similar symptoms and spent some time cleaning, balancing and tuning the carbs, checking intake manifold leaks, etc.
The idling was rather rough too. It seemed like only three cylinders were firing at 1000 rpm.

It appeared that #3 carb wasn't comfortable with standard 2.5 turns A/F screw setup. Everything runs smoothly (in V4 terms :biglaugh when it's closer to 4 turns actually.
I tried to exchange screws and rubbers with no effect. The #3 likes A/F screw at 3.75 that's it.

PM me. I am located in Giffnock.

 

[sdt354]

I had similar symptoms and spent some time cleaning, balancing and tuning the carbs, checking intake manifold leaks, etc.
The idling was rather rough too. It seemed like only three cylinders were firing at 1000 rpm.

It appeared that #3 carb wasn't comfortable with standard 2.5 turns A/F screw setup. Everything runs smoothly (in V4 terms :biglaugh when it's closer to 4 turns actually.
I tried to exchange screws and rubbers with no effect. The #3 likes A/F screw at 3.75 that's it.

PM me. I am located in Giffnock.

If you were to check an unmolested carb set, the A/F screws wouldn't all be the same. The factory sets them for emission purposes. Two of my own, most definitely molested, are set different than the others. After 3 1/2 turns out there isn't as much spring tension holding the A/F screws steady. A larger set of pilots can remedy this. I've stretched the spring a bit too, but like the larger slow jet remedy better. Imho that is.

 

[grimmie]

Are you running stock coils? I had the same thing going on and it ended up being one of the stock coils.