Ok so here is what we have. Bought a 96 F3 this winter as my first bike that had quit running one day for the previous owner. After looking into it the fuel cut relay was bad. Replaced that and the bike ran fine. Since then it has started every time no problem but i have yet to ride it very far as it is in very bad need of a chain. (Live in Indy so no point yet in replacing as who knows what the weather is gonna do in 5 mins.) Bike has sat in the garage for a couple weeks now and today I choke the bike hit the start button and it fires right up. It starts to warm up the rpms start to climb and I start to back the choke off. Rpms start to drop, bike starts to bog so I "add" a little more choke. Bike dies and I restart with full choke. At this point the bike will start with full choke on (all the way towards me) for about 5 seconds at very very low rpms (5-700) and will die. Wont at all with any gas applied or with the choke in any other position other than ON. There is plenty of gas and the pump and filter are good. ANY thing at this point will help!!

 

How old is the fuel in the tank?

 

When you start a bike up from cold using the choke, once it starts to warm up, even for a couple of minutes. Pulling the choke back on (riching the mix) will always cause the engine to splutter as the mix is to rich. You could try just using the throttle once the the revs go up & you back the choke right off.
My F3 is a bugger sometimes to start if I don't get it right in the 1st place. I've found with mine that leaving the petrol in 'Off ' position makes a big difference when I 1st crank it over & I don't go any where near the throttle. Few things, pull one of your plugs & check their condition, throw in some new fuel, check your air filter. Maybe just needs bloody good ride.

 

Use the choke to start it and warm it up, after a few mins when the rpms really start to climb turn the choke off and turn your idle adjuster clockwise a little and see if it stops from bogging.

Thats what I did when my 95 acted this way after sitting in my garage all winter. If all else fails check out your carbs and see that everything is clean... New gas too

 

Fuel in the tank in a high octane from last May or so but it has stabilizer in it. Could this be the problem? My plan is to drain out the tank and pull a plug or to today and see how those look. Carbs had been cleaned last summer.

 

Just talked to the previous owner as he is a co-worker of mine. Ok so last summer he had a full tune up done. Plugs wires carbs cleaned new o-rings cleaned out the gas tank new air filter the whole 9 right. Rode it daily and put it up one day and the next it was doing the exact same thing as I have described above. He never got it running and sold it to me. I replaced the fuel cut relay and presto. Bike was perfect! Now its back to square one. My next question is could there be something shorting out this fuel cut relay so fast? I'm stumped and really don't want to have to take this to a dealer!

 

check the plugs... no sense looking all over the place when it could be that your plugs are fouling up.

 

I agree. It sounds like a fouled plug to me. Those bikes are very finiky when its cold outside. You have to have a fully charged battery and do the procedure exactly right or you'll end up with fouled plugs. with such a low idle, your probably only running on 3 cylinders.

I would also pull them to make sure he put in good plugs. I would only suggest ngk's. Is it possible he just cleaned the old plugs instead of buying new ones?, therefore the problem never went away. Keep in mind, just because a spark plug sparks outside the combustion chamber, doesn't mean its sparking once gas and compression are added to the mix. If the plugs aren't sparking a really nice blue spark, I'd change em out.

 

Update: Messed with the bike when I got off work today and to keep this somewhat short I will say that the fuel cut relay that I had replaced earlier was the culprit. After talking to my co-worker a little today I decided to by pass it and the bike started and ran like a champ! So I have "fixed" the problem by by passing the fuel pump and running gravity feed system. I know the pump is good because I hooked it up to the battery with a DVOM meter. Looking at wire diagram in the shop manual, the only thing that looks like it could be causing this relay to go bad is something between the relay and the ignition control module. Anyone ever had an ICM go bad or been in a situation like this? And thanks for all the responses and suggestion. I love CBRF!!