ER5 Bogging down when accelerating

[ncrn]

Hey, yesterday I rode my ER-5 from my parents back to mine (60 miles of motorway) everything was fine.

Today I rode to work (40 miles of motorway approx) and I noticed that the bike was bogging down whenever the revs passed 5,000rpm, it feels like the bike needs to go onto reserve but I filled the fuel tank this morning. If I put the bike on reserve the same thing happens.

Any ideas what might be causing this? My guess is there is something blocking the fuel line or maybe there is something in the jets in the carbs but I was wondering if anything else might be causing this? I have fitted a set of heated grips to the bike recently, but when I turned them off the bike was still bogging down, would a weak spark cause the same sort of behaviour?

Thanks and sorry if the layout/spelling is bad, I've typed this on my phone.

James
____________________
Past: 55 Sym Jet, 91 ZZR250, 03 NSR125R. Present: 97 ER-5.
https://www.nsr125.co.uk - NSR Owners forum.

[Willson]

I had problems like that with mine, try:

Charging the battery, changing the spark plugs, try using some Redex fuel system cleaner (Not the injector cleaner) next time you fill up as well.

Also, try disconnecting the heated grips and see if you have the same problems.

HTH

Willson
____________________
Benson: Wouldn't life be easier if we were all turtles?
Me: Pig on bread = The way forward.
Riding: '00 Suzuki SV650S. Previous: '99 Kawasaki ER5 - sold, '02 Suzuki GZ125 Marauder - sold

[Paxovasa]

Might just be carb icing.

Did it last for the whole journey or just for a short time?
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Suzuki GSF600 K3 (in the fastest colour, black).

[ncrn]

I'll disconnect the grips for the ride homecoming and I'll try get some redex. It started about 10 miles in and didn't stop, the air temp was about 5 degrees so I wouldn't have thought it was icing. Although its a possibility.
____________________
Past: 55 Sym Jet, 91 ZZR250, 03 NSR125R. Present: 97 ER-5.
https://www.nsr125.co.uk - NSR Owners forum.

[whitedevil]

doesnt the er-5 have heated carbs? i know the gpz does and they're pretty much the same bike

[stinkwheel]

Aye. They have carb heaters that run off the coolant system.

I would suggest checking your air filter. It could be clogged or coming apart.

Does it start pulling normally again if you keep the throttle pinned until the revs go above 8,000?

If so, there is a "power jet" built into the carb on these bikes (located round the edge of the choke where they attach to the airbox rubbers). These fill in a massive fuelling deadspot at around 7k rpm. If they become blocked, it'll run fine at low and high revs but the midrange is non-existant. They are commonly blocked by bits of knackered air filter when they go. The jets themselves can't be removed but can be blown through with compressed air.

*cough* Don't ask me how I know.
https://i48.photobucket.com/albums/f216/stinkwheel/airfilter.jpg
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[ncrn]

I hadn't tried pushing it beyond 8k revs I'll try that on my way to uni tomorrow.

As an update I turned off the heated grips and it made no difference at all. I did notice however that if I put the choke on it started running, not normally, but it felt a lot better. It made a huge difference when going up a very large hill on the motorway.

I'll pop the air filter off before I ride to check its not coming away. It is fairly old, about 13k miles according to my service notes.

Cheers for the advice guys
____________________
Past: 55 Sym Jet, 91 ZZR250, 03 NSR125R. Present: 97 ER-5.
https://www.nsr125.co.uk - NSR Owners forum.

[Willson]

+1 with what Stinkwheel said, worth a try!

13k miles? Mine's done 45k+ 0_o.

Took the cylinder head off the other day and it looks like it hasn't seen daylight since it left the factory...
____________________
Benson: Wouldn't life be easier if we were all turtles?
Me: Pig on bread = The way forward.
Riding: '00 Suzuki SV650S. Previous: '99 Kawasaki ER5 - sold, '02 Suzuki GZ125 Marauder - sold

[cb1rocket]

sounds like the bike is starving of fuel due to vacuum in the tank.

When it bogs down, pull over and open the filler cap and listen for a whoosh of air.

Another way would be to ride with the cap slighty open and see if that cures it.

If so you have a tank breather blockage.

[temeluchus]

if the carb heaters are anything like the ones on my gpz1100 then they are cack!

tried draining the float bowls in case some water has creeped in?
____________________
Some shite cruiser. Now with guns and FREEDOM!

[ncrn]

I tried gunning it on the way home but I ran out of road before it could get past 7k rpm, it felt like it was picking up as it got there though. I should hopefully have some time tomorrow morning to pull the carbs off and have a clean out. I'm hoping its just something simple like a blocked jet.
____________________
Past: 55 Sym Jet, 91 ZZR250, 03 NSR125R. Present: 97 ER-5.
https://www.nsr125.co.uk - NSR Owners forum.