96 Bandit losing power and spluttering

[Baffler186]

Bought a bandit privately and picked it up today - everything was fine until riding it on the dual carriageway at 70ish, after about 10 minutes it lost about 60% of it's power and I just managed to keep it going but wouldn't get past 5k RPM in 4th despite having throttle right open - I managed to limp it to a Tesco and it's there now.

Details: it has 8 months MOT left, has had new oil and filters. CArbs haven't been cleaned and balanced so might be that, I've ruled out carb icing as it was about 10 degrees out but it was very wet.

Is there anything obvious I should check first before booking it into a garage? I had carbs out on a 125 but never done this with bigger bike before, is it the same principal? Also I will check leads and plugs, but it felt like it was running much worse than having dropped just one cylinder.

Any advice would be good, first big bike and it's really done my head in!

[P.addy]

Was it raining? Is it a vacuum tap on the Bandit? I can't remember.

[Baffler186]

[J.M.]

[Baffler186]

[J.M.]

[ZebraDriver]

Try putting petrol in it.

[Baffler186]

[P.addy]

Check coils under tank. Also check caps on the spark plugs and make sure they aren't perished, water might be getting in and shorting it out.

[Baffler186]

[_Iain_]

Fire it up and keep touching the headers one by one to judge temp.

Bandits are very obvious to spot & the cold one isn't firing. Probbably a coil issue - I may have a few in a box somewhere.
____________________
Please be aware that the above post may be full of complete nonsense.
Riding: '07 KTM Duke II, Baotian BT49QT-20 Driving: '88 Volvo 340

[J.M.]

[davebike]

For a bet Bought privet from Ebay Put a set Good plugs and a clean air filter and it will run fine Do an oil change as I don't expect that been done in awhile !!

Dave
____________________
Dave
NC750Xdct + others at work !
[email protected]

[Baffler186]

[Baffler186]

Thanks all for taking the time to post. Taking it to garage now, want it done properly

[Nemo]

Im gonna place bets on the carbs need cleaning out and setting up, sounds like the main jets are gummed up.

Carbs are a peice of cake to remove and clean out, but you'll need vacuum guages to sort the balancing, and a good ear to do the mixtures, so unless you're 100% cinfident, don't touch them.

Had the bike been sat for a while before you bought it? Petrol can go bad and gum up in as little as 1 - 2 weeks of not moving.
____________________
Previously owned: Kawasaki KH125, Suzuki GP125, Suzuki GX 125, Honda CB125 TDC '83, Honda ntv 600, Kawasaki ER5, Kawasaki ZZR600, Aprilia RSV 1000 Mille
Now own: Ducati 848 evo

[Baffler186]

[haroman666]

Make sure water isn't getting into the carb's at all either.
My Bandit 400 had a pipe that went from the fuel-cap overspill straight to the carbs. Which meant it fed water straight to the carbs in the rain as there was no seal around the overspill bit.
I ended up buying coils, HT leads, plugs that I didn't need. Spent more time than it was worth looking over the wiring and I nearly bought a new CDI unit.

Until I discovered that when I poured water on the fuel cap (With it closed obviously) it eventually cut the engine.

Just a thought. I'm not sure if B6's have this pipe.
____________________
The mistresses: 2000 Honda CBR600f, 2000 Honda VTR1000

[yampug]

blocked jets

[Baffler186]

Bit of an update: The garage balanced the carbs and said it was running fine (though they only took it for a 5 minute ride to test it). Took it out on Saturday and it was fine for 30 miles. Then after having been at 70/80 for 20 minutes it started to die again, then stalled at the end of a slip-road. I got it started again and got it home keeping in low gear at high revs.

I was convinced it was carb icing, as it had only up to now happened in the damp/cold and when doing prolonged rides with the throttle in the same place.

However, this morning I had only just warmed it up and it did the same thing after only doing 2 miles at 30mph. Also it wasn't wet (bike had been in dry garage with dehumidifier going all night, and it wasn't raining outside), so I think I can eliminate all of the problems caused by water.

So, here's what it has had done:

Carbs balanced
Electrics checked
New spark plugs
oil change + new oil filter
new air filter
New battery


I'm going to check all the wiring at the weekend, and the carbs, and the fuel breather pipe. Hopefully something obvious will need doing, but other than that if I can't get to the bottom of it will have to go back to the garage. Will also put some fuel system cleaner in, run it, and then check carbs.

If any of the above is not a sensible approach please shout!

[haroman666]

For carb icing, stick nearly a cap of THIS in each tank of fuel.

I have a bottle somewhere but fuck knows where.

Also check your plug leads... May be degrading or cracked. You can get 2 meters worth on ebay for a couple of quid and you can cut it to length and screw into your plug caps and coils to replace what you have there.
____________________
The mistresses: 2000 Honda CBR600f, 2000 Honda VTR1000

[P.addy]

Have you removed and cleaned the carbs?

[Baffler186]

I have just ordered some Isopropanol so will try that when it arrives (I've been told a 1% mix i.e. 180ml/18 litre full tank?). The garage said the carbs and fuel system were fine. I'm going to take the tank off at the weekend and check all the electrics and plug leads etc.

It's a funny old problem, there seems to be no pattern to it (has done it once after 2 minutes of slow riding, and another time after half an hour at 70). Also when it dies, it immediately re-starts and idles fine, but starts a lot better when I switch the tap to prime so may be a fuelling issue. Time will tell.

cheers guys

[chris-red]

My money is on the coils, find out what cylinders it is missing on and see if they are fed by the same coil. If they are swap the coils over, (leaving the leads plugs caps etc where they are) if it starts missing again on the other cylinders replace both coils. If it stays on the same cylinders replace leads/caps.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[Baffler186]