Engine dies as I come to a stop.

[rixter66]

Howdy all, new to the site and new 1200S owner. Just purchased a 2004 with 4700 miles that had sat in the garage for a year prior to the previous owner selling. There was a lagging issue around 3000 RPM that seems to have gone away after running a tank with SEA-FOAM in it, but now the engine dies every so often as I come to a stop. Could this be related to the TPS sensor or does it sound like varnish in the carb bowls? Any input would be helpful. BTW, the engine idles around 900 RPM when hot.

[Snubnose]

BTW, the engine idles around 9000 RPM when hot.

9000 rpm is awful high, shouldn't be more then 1300-1400 rpm. I have a 2003. Sounds like somethings stuck open , probably due to remaining gunk somewhere. I'd say a Carb clean is in order, specifically the idle jets.

[rixter66]

Typo. I meant 900 RPM.

[Jimmy Tom]

Sounds like you're a little low then.  I remember when I first got my Bandit it seemed too high, manual reports 1200 +/- 100, mine likes 1300.

Hope this helps.

[Sven]

Sounds like you're a little low then.  I remember when I first got my Bandit it seemed too high, manual reports 1200 +/- 100, mine likes 1300.

+1 on that answer!

[CWO4GUNNER]

IMO after sitting that long the main jets and idler jets are probubly varnished and partially and in some cases fully clogged. I would purchase new jets since varnished jets can remain narrowed with diminished clearance even after cleaning with chemicals. So buy the new replacement jets (cheap), remove the crab rack, remove one bowl at a time and remove old jets, spray carb with pressurized can solvent straw and brush, install new jets, replace bowl, and repeat for each carb on rack. Start up engine synchronize carbs.

I had to do this once to my 05 B1200, but after trading up to my 07 B1250 I have let it sit for 6 months and the EFI has never given me that problem, not even a hiccup and Im still procrastinating on synchronizing the throttle bodies becasue it still runs like the day I first drove it off the lot.

[rixter66]

Thanks for all the info. I was wondering at this point if it would be most benificial to re-jet with a stage 1 kit and put on a new exhaust. Any reccomendations?

[CWO4GUNNER]

Sound like the next logical step for an engine that is running right, but you haven't isolated the problem yet and besides the upgrade kit only includes the main jets not the smaller idler jets which are much smaller and therefore more prone to clogging, and probubly why you have the RPM set high. Isolate the problem first in a stock configuration as a set of 8 jets will cost you only about $20 if that. Then after it running according to spec, upgrade IMO.

[rixter66]

Thanks for all the input. I raised the idle to 1000-1100 and that seemed to take care of the dying issue. I have read a few of the threads on the Jet-Exhaust alternatives and would like to know if it is really adventageous to do it. Any suggestions?

[Red01]

I have read a few of the threads on the Jet-Exhaust alternatives and would like to know if it is really adventageous to do it.

It's advantageous to do it if you want an extra 15-20 horsepower at the cost of a couple of mpg and a louder exhaust tone.

[02blue]

DO it!

[rixter66]

What is the reality. I have read that it will improve mileage, and also that it will kill it.

[Red01]

The reality is every bike is different.  Most will see a slight drop in economy, a few see a slight increase, and a few see a drastic drop (8 mpg or more).  Some will be related to how and where the bike is ridden.  Some will be due to how well the carbs are setup.  Some may be due to the company that supplies the jet kit. 

From being a long time member here, Irfan's old Bandit email list and other Bandit related sites, it appears to me, the bikes with the drastic drop in economy almost always chose a Dynojet kit.  The DJ kit also appears to have the most people asking for tuning help getting their bike dialed in. This, along with thier use of a proprietary jet numbering system that does not correspond to Mikuni jet numbers makes me want to stay away from their B12 kits.  To be fair, there are folks that have installed their kits with no issues, and for many other kinds of bikes, they are the preferred way to go, but IMHO, the B12 is not their strong suit and I think Factory-Pro, Holeshot or Ivan's are better for the B12.