Author Topic: Im flumoxed (Read 8233 times)

grizzler · « **on:** 30 May 2016, 08:42:19 pm »

Ok everyone any assistance with this problem wont get my hair back but it will help me stop making the head sized hole in my garage wall any bigger. My 03 fzs600 foxeye is playing silly beggars. If I ride for several miles at a speed over 70mph she dies as in fuel starvation. A few on/offs of the ignition and the cards are primed and were moving again. 60 mph is fine she will run all day. So logic says the fuel pump is caput yet it seems to be in fine working order, points and all. So could the tps cause the pump to pump slow? Even if the tps checks out ok when tested? Help!!!!!

joebloggs · « **Reply #1 on:** 30 May 2016, 08:50:16 pm »

Airlock?
You tried riding at same speed with your fuel cap open, not with a full tank please

red98 · « **Reply #2 on:** 30 May 2016, 08:52:16 pm »

Have you checked the fuel filter ?

Shappaeye · « **Reply #3 on:** 30 May 2016, 08:58:34 pm »

Checked the air filter? Sucking too much air perhaps?

grizzler · « **Reply #4 on:** 30 May 2016, 09:35:40 pm »

Shappaeye, she has had a new air filter. no difference. red 98, she has had a new fuel filter. no difference. joebloggs, that's a new idea i will try it out when the fuel level allows.. Thanks everyone. all suggestions are gratefully accepted...

darrsi · « **Reply #5 on:** 30 May 2016, 09:38:40 pm »

TPS won't affect it like that.
Next time it does it undo the fuel cap and see if the tank gasps for air.
Or just make sure the breather hole is clear anyway.
Also make sure your fuel tap is turned fully on.

joebloggs · « **Reply #6 on:** 30 May 2016, 09:40:10 pm »

Quote from: Shappaeye on 30 May 2016, 08:58:34 pm

Checked the air filter? Sucking too much air perhaps?

Sorry but how the foc would u check the airflow through a filter and if by chance it was flowing more air than usual, would it cause the above symptom.
Check the other two.

darrsi · « **Reply #7 on:** 30 May 2016, 09:48:12 pm »

Quote from: joebloggs on 30 May 2016, 09:40:10 pm

Quote from: Shappaeye on 30 May 2016, 08:58:34 pm
Checked the air filter? Sucking too much air perhaps?

Sorry but how the foc would u check the airflow through a filter and if by chance it was flowing more air than usual, would it cause the above symptom.
Check the other two.

As long as it's not a leak it would probably appreciate the air at higher speeds, bit like if you added a K&N filter.
If it was an air leak, like at the carb rubbers for instance, the bike would just bog down every time you try and overtake or give it a bit of welly.

grizzler · « **Reply #8 on:** 30 May 2016, 09:58:34 pm »

Trust me when i say she can zoom, just not for long..lol.. She accelerates very well and just keeps on pulling.
I replaced all filters when i replaced the engine. I had the same symptoms with the old engine (and no i didn't change the engine because of this problem). The gearbox was on it's last cogs..lol..
I luckily got my mits on a sweet 23000 miler for £50 off flee bay.

grizzler · « **Reply #9 on:** 30 May 2016, 10:27:11 pm »

Just had a quick check on the breather and it seems fine. i shall continue

for now..lol...

unfazed · « **Reply #10 on:** 30 May 2016, 10:45:04 pm »

What you need to do is rule things out.

Lift the tank check to ensure the fuel pipe is not kinked and routed properly, it should be routed under the frame cross brace and not over it.
If it is over it reroute it under the cross brace

Check the flow from the Fuel tap, lift the tank turn off the fuel tap pull off the hose and attach a long piece of hose to it. direct it into a can, turn on the tap, there should be a full even flow.

Next is do what Joebloggs suggested, rule out a blocked tank vent and ride it with the fuel cap open. If it is ok with the cap open, clear out the tank vent. Press in the two clasps to release the key and put the cap down but not closed.

If the problem still exists, bypass the pump by connecting the pump outlet to the fuel filter outlet, now fill the tank to the absolute brim, a full tank will not require the fuel pump. If it is ok now replace the pump.

Let us know how you get on

grizzler · « **Reply #11 on:** 30 May 2016, 10:49:59 pm »

Cheers for those ideas, fuel pipe is not kinked and routed correctly, the other checks shall be attempted this week as time permits..

Thanks for the advice everyone. More ideas are still welcome..

Bretty · « **Reply #12 on:** 30 May 2016, 11:17:59 pm »

Just out of interest.. what tells the fuel pump when to come on and off? And how does it decide when to be on and off?

Mine ticks away when the ignition is first switched on. I assume filling the carbs, but what tells it to stop? Is it constant speed or variable? It's one of those things I've never taken the time to understand.

Sorry to detract from the original post.. although on topic.

Shappaeye · « **Reply #13 on:** 31 May 2016, 12:08:04 am »

Quote from: joebloggs on 30 May 2016, 09:40:10 pm

Quote from: Shappaeye on 30 May 2016, 08:58:34 pm
Checked the air filter? Sucking too much air perhaps?

Sorry but how the foc would u check the airflow through a filter and if by chance it was flowing more air than usual, would it cause the above symptom.
Check the other two.

Just trying to help, heard a call for assistance, so I contributed. I won't do that again in a hurry!

Sent from my iPhone using Tapatalk

Jules-C · « **Reply #14 on:** 31 May 2016, 08:47:06 am »

Quote from: Bretty on 30 May 2016, 11:17:59 pm

Just out of interest.. what tells the fuel pump when to come on and off? And how does it decide when to be on and off?

Mine ticks away when the ignition is first switched on. I assume filling the carbs, but what tells it to stop? Is it constant speed or variable? It's one of those things I've never taken the time to understand.

Sorry to detract from the original post.. although on topic.

There is a pressure switch built into the pump that switched it off

joebloggs · « **Reply #15 on:** 31 May 2016, 09:17:17 am »

Quote from: Shappaeye on 31 May 2016, 12:08:04 am

Quote from: joebloggs on 30 May 2016, 09:40:10 pm
Quote from: Shappaeye on 30 May 2016, 08:58:34 pm
Checked the air filter? Sucking too much air perhaps?

Sorry but how the foc would u check the airflow through a filter and if by chance it was flowing more air than usual, would it cause the above symptom.
Check the other two.

Just trying to help, heard a call for assistance, so I contributed. I won't do that again in a hurry!

Sent from my iPhone using Tapatalk

Don't take my comment to heart, having myths dismissed is good for the forum.

Fazerider · « **Reply #16 on:** 31 May 2016, 09:20:43 am »

You say you've changed the fuel filter, but there are three in all...
It'd be worth checking the one in the tank attached to the fuel tap and the little one in the T-piece at the back of the carbs.

Shappaeye · « **Reply #17 on:** 31 May 2016, 09:35:54 am »

Quote from: joebloggs on 31 May 2016, 09:17:17 am

Quote from: Shappaeye on 31 May 2016, 12:08:04 am
Quote from: joebloggs on 30 May 2016, 09:40:10 pm
Quote from: Shappaeye on 30 May 2016, 08:58:34 pm
Checked the air filter? Sucking too much air perhaps?

Sorry but how the foc would u check the airflow through a filter and if by chance it was flowing more air than usual, would it cause the above symptom.
Check the other two.

Just trying to help, heard a call for assistance, so I contributed. I won't do that again in a hurry!

Sent from my iPhone using Tapatalk

Don't take my comment to heart, having myths dismissed is good for the forum.

That's a good point actually, now I've stopped crying into my helmet, I understand, thank you.

Sent from my iPhone using Tapatalk

grizzler · « **Reply #18 on:** 01 June 2016, 07:03:20 pm »

Some very good ideas have been put forward here and i thank each and every one of you for them. Re tank open--- It made no difference so i'm going to remove that possibility. I checked the T piece filters when i had the carbs off during the engine replacement and they are fine. I've not checked the tank one yet but will as soon as i can though the fuel flow seems fast and constant when poured directly from the tap. getting a bit stressed now as i'm due to take on Germany in 3 weeks and still cant find the cause.. German autobahns at 60mph is not appealing..lol...

joebloggs · « **Reply #19 on:** 01 June 2016, 08:18:25 pm »

I'd take a quick look at the carb diaphragms just incase they are perished or split. Could be that its not starved of fuel but that the slides wont lift high enough

taylor · « **Reply #20 on:** 01 June 2016, 08:19:34 pm »

I notice you got a new engine, its not restricted is it.

joebloggs · « **Reply #21 on:** 01 June 2016, 08:33:11 pm »

If you had the issue before then I would definitely be pulling the carb tops off, my old 600R had a split diaphragm and it would pull hard in the lower gears then struggle once under load at higher speeds. It may not be that simple but an easy one to rule out

grizzler · « **Reply #22 on:** 01 June 2016, 09:32:54 pm »

joebloggs, diaphragms are a ok (checked when stripped n cleaned). She pulls up to 120 and my bottle goes before the bikes willingness to go faster..lol..
Just for a bit more info, i believe it's a fuel starvation problem because i have to prime the carbs again after she conks out. I just cant seem to find the reason the fuel doesn't flow fast enough at higher speeds as it's a hard thing to test at 80mph..lol..

Arfa · « **Reply #23 on:** 01 June 2016, 09:47:32 pm »

Hmm very odd, had similar symptoms with my wife's old zzr400. Unfortunately, I never did resolve it. :-( Does it only become a problem when. travelling at 70 odd? I mean when at stand still can you rev the engine to a similar point? If so, then this may imply it's related to air flow at speed, or the Speed/gear the bike is in. We always suspected the Jap imported zzr400 was restricted based on speed/gear (did try grounding wires from CDI), or the ram air intake.

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Fazerider · « **Reply #24 on:** 01 June 2016, 10:00:58 pm »

Maybe the fuel is getting restricted after the T-piece.
If you compare the flow rates you can get from the carb drains it might be possible to judge which one isn't filling as fast as the others. It takes a surprisingly long time to empty a float bowl so you'd need to let each one pour for a couple of minutes before making a measurement.