Author Topic: Loss of power then fine? ? (Read 8232 times)

odbguy · « **on:** 21 June 2015, 09:08:58 pm »

I was out on the bike over weekend and on two occasions with on 5 mins I felt a weird loss of power.
The 1st time I had gone through the gears at a normal rate and in 6th at around 80mph the bike began to feel like it was struggling. And started making a noise, the only way I can describe the noise would be like if you was pulling of in 1st gear and don't give it enough revs.
I tried to power through it, which made no difference so I pulled over. I revved the bike up a few times and decided to take it all way through the rev range but in a steady manner. .
It went fine up until 6th when at about 8k revs the bike seemed to have a complete loss of power. Shoving me forward, to be honest I shit myself thinking I was gonna go through the fairing! Lol
It was only quick tho, a split 2nd as if I had just dabbed the brake on .. which I hadn't! Lol
After that it ran fine so iv been racking my mind wondering what it could be. I had just filled it up and thought maybe a bit of shit clogging something up then clearing? I'm going to buy some carb clean to try rule that out? Anyone else got any suggestions please?

darrsi · « **Reply #1 on:** 21 June 2015, 10:02:32 pm »

Air filter okay?

odbguy · « **Reply #2 on:** 21 June 2015, 11:17:44 pm »

I did wonder about the air filter. I haven't checked it, but was thinking while I did I could replace it with a k&n??

darrsi · « **Reply #3 on:** 22 June 2015, 06:12:27 am »

Quote from: odbguy on 21 June 2015, 11:17:44 pm

I did wonder about the air filter. I haven't checked it, but was thinking while I did I could replace it with a k&n??

Loss of power under pressure could well be a grubby or blocked air filter, i've just had a similar thing happen to my bike.
I have the K&N on mine, as do quite a few people and it does make a big difference in my opinion.
Whichever way you go, just don't buy the cheapest air filter out there, either try a K&N which are washable or an OEM Yamaha one.

odbguy · « **Reply #4 on:** 22 June 2015, 08:48:31 am »

Yeah I have read through your subject and Grizzlers to see the similarities and what yous did to sort it.
Air filter seems like the obvious 1st thing to check, and best excuse to treat myself to k&n.. going rate seems to be 37quid on fleabay. That sound about right ?

darrsi · « **Reply #5 on:** 22 June 2015, 11:39:52 am »

Quote from: odbguy on 22 June 2015, 08:48:31 am

Yeah I have read through your subject and Grizzlers to see the similarities and what yous did to sort it.
Air filter seems like the obvious 1st thing to check, and best excuse to treat myself to k&n.. going rate seems to be 37quid on fleabay. That sound about right ?

Yep.

Freck · « **Reply #6 on:** 22 June 2015, 12:05:34 pm »

Sounds to me like you're getting intermittent fuel starvation, maybe a fuel filter clogging up or some crud has got into the carbs. I've had similar symptoms before with a gunned up filter.
You say you'd just filled it up, was it really empty? Could be some crud from the bottom of the tank been disturbed if it was really low on fuel.

Steve

odbguy · « **Reply #7 on:** 22 June 2015, 12:35:14 pm »

Quote from: Freck on 22 June 2015, 12:05:34 pm

Sounds to me like you're getting intermittent fuel starvation, maybe a fuel filter clogging up or some crud has got into the carbs. I've had similar symptoms before with a gunned up filter.
You say you'd just filled it up, was it really empty? Could be some crud from the bottom of the tank been disturbed if it was really low on fuel.

Steve

Hey Steve ta for your reply.
Yeah it was pretty low to be fair, I was thinking along the same lines as you.
I'll try a bit of carb clean for now, then when I get paid il change the air and fuel filter hopefully that will cure it and then some :/

Robbie8666 · « **Reply #8 on:** 23 June 2015, 08:09:49 am »

arrrr I have had the same on my bike since I made a small mistake by filling up with diesel not petrol!!
I had it drained & cleaned but seems like I need to check the air filter!

only happens at bout 80 ish so will check it out, thanks

odbguy · « **Reply #9 on:** 23 June 2015, 08:16:50 am »

Quote from: Robbie8666 on 23 June 2015, 08:09:49 am

arrrr I have had the same on my bike since I made a small mistake by filling up with diesel not petrol!!
I had it drained & cleaned but seems like I need to check the air filter!

only happens at bout 80 ish so will check it out, thanks

Filling with diesel ?! Gutted mate.
Guessing you was just in auto mode and didn't think til it was too late. :/

darrsi · « **Reply #10 on:** 23 June 2015, 08:36:26 am »

Quote from: Robbie8666 on 23 June 2015, 08:09:49 am

arrrr I have had the same on my bike since I made a small mistake by filling up with diesel not petrol!!
I had it drained & cleaned but seems like I need to check the air filter!

only happens at bout 80 ish so will check it out, thanks

I'd be inclined to change the fuel filter too.

Robbie8666 · « **Reply #11 on:** 23 June 2015, 03:01:29 pm »

Quote from: odbguy on 23 June 2015, 08:16:50 am

Quote from: Robbie8666 on 23 June 2015, 08:09:49 am
arrrr I have had the same on my bike since I made a small mistake by filling up with diesel not petrol!!
I had it drained & cleaned but seems like I need to check the air filter!

only happens at bout 80 ish so will check it out, thanks

Filling with diesel ?! Gutted mate.
Guessing you was just in auto mode and didn't think til it was too late. :/

yeah was 0630 in morning and as you say on auto pilot from the car! got 2.4 miles down the road when it conked out!!
luckily bike was due MoT & service so bike drained tank & carbs, cleaned plugs then MoT'd all for £150 so got away lightly!
maybe need airfilter so will do that soon

odbguy · « **Reply #12 on:** 23 June 2015, 09:25:26 pm »

That is lucky ... kind off .. haha
I always check my stickers before I fill up

lol

Robbie8666 · « **Reply #13 on:** 24 June 2015, 08:47:35 am »

I realise now that morrisons (where I usually fill up) use black pipes for both diesel & petrol with only the cap round the nozzle green or black as opposed to other petrol stations using green & Black pipes!
I am definitely more alert when filling up now though!!
I've filled up with premium unleaded this tank full see if that makes a difference & clean it out a bit!!
riding up to Nottingham this evening so will see if it makes a difference!!

odbguy · « **Reply #14 on:** 26 June 2015, 10:36:44 am »

I had the tank of this morning and checked the air filter. It's absolutely fine ..
But it's not been out since last week and I'm just nipping to donny so will see how it fairs.
I had a bit of trouble getting her running after.
There was no life at all and after taking the tank of and refitting it incase I forgot something I had to bump it off. That normal? Just to get the fuel circulating again ??

darrsi · « **Reply #15 on:** 26 June 2015, 01:14:12 pm »

There was no life at all and after taking the tank of and refitting it incase I forgot something I had to bump it off.

You killed your bike?

odbguy · « **Reply #16 on:** 26 June 2015, 03:08:40 pm »

Quote from: darrsi on 26 June 2015, 01:14:12 pm

You killed your bike?

Haha I thought I had, the tank came on and off 3 times thinking I had missed something. Followed by a mini panic running up and down the drive trying to bump it then it started. Lol
It ran spot on to Donny and back, about 50 miles. Then I filled it up cos it waw running low and it started running dodgy again ...
So I think I need to give the tank a good clean perhaps and change fuel filter ?? :/

Freck · « **Reply #17 on:** 26 June 2015, 08:47:55 pm »

Have a try riding it with the fuel cap open, well just unlocked. I've heard before of running problems being caused by the fuel cap vent being partially blocked.
Something to do with a vacuum being created in the tank causing starvation to the carbs.... Worth a try

I would still change the fuel filter too for what they cost.

Steve

odbguy · « **Reply #18 on:** 27 June 2015, 04:22:23 pm »

Hmm I will look into that idea cheers Freck.
Yeah definitely gonna change fuel filter. And air filter still too.
Hopefully changing the fuel filter will rectify the problem.

darrsi · « **Reply #19 on:** 27 June 2015, 04:42:23 pm »

Quote from: Freck on 26 June 2015, 08:47:55 pm

Have a try riding it with the fuel cap open, well just unlocked. I've heard before of running problems being caused by the fuel cap vent being partially blocked.
Something to do with a vacuum being created in the tank causing starvation to the carbs.... Worth a try
I would still change the fuel filter too for what they cost.

Steve

Bit dangerous that trick, if it is a blocked air vent then next time it happens open the fuel cap and see if the tank gasps for air.

Freck · « **Reply #20 on:** 27 June 2015, 05:32:58 pm »

Quote from: darrsi on 27 June 2015, 04:42:23 pm

Quote from: Freck on 26 June 2015, 08:47:55 pm
Have a try riding it with the fuel cap open, well just unlocked. I've heard before of running problems being caused by the fuel cap vent being partially blocked.
Something to do with a vacuum being created in the tank causing starvation to the carbs.... Worth a try
I would still change the fuel filter too for what they cost.

Steve

Bit dangerous that trick, if it is a blocked air vent then next time it happens open the fuel cap and see if the tank gasps for air.

Lol, I only meant down the road slow speed maybe in a quiet car park, not a 50 mile country lane scratch with his knee down

odbguy · « **Reply #21 on:** 28 June 2015, 03:20:08 pm »

If it is a blocked air vent how can i sort that?
Will riding it steady round a car park or something solve the problem ??
Sorry if that's a stupid question ? :/ ha

darrsi · « **Reply #22 on:** 28 June 2015, 03:39:41 pm »

Different bike, but explains quite well.

http://www.apriliaforum.com/forums/showthread.php?274808-Where-is-the-breather-hole-in-the-fuel-tank

odbguy · « **Reply #23 on:** 28 June 2015, 05:59:11 pm »

Quote from: darrsi on 28 June 2015, 03:39:41 pm

Different bike, but explains quite well.

http://www.apriliaforum.com/forums/showthread.php?274808-Where-is-the-breather-hole-in-the-fuel-tank

Ahhh nice one cheers darrsi.
I will have a look Friday morning when I'm home. Cheers

odbguy · « **Reply #24 on:** 06 August 2015, 08:57:17 pm »

So this problem has returned?
The bike just started running OK and has been fine up til today and is worse than before.
I'm thinking of changing the spark plugs but left the trusty Haynes manual on camp and I'm on leave now

Is it possible to leave tank on and change plugs or is that just making the job awkward for myself and should take of the tank and other parts above the plugs.