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Discussion Starter #1
Hi guys, hoping the brains trust can guide me with my issues.
My 750 had a 42k service 1500 kms ago. As I commute I hadn't revved it much but in a spirited ride the other day I discovered the bike wouldn't rev past around the 9000 rpm range. Occasionally it would get to 10ish but wouldn't hit redline.
Hoping it was something simple I replaced the fuel filter. Prob remains and is gradually getting worse. Now it's struggling to get past 6000.
All fuel lines looked fine.
I've replaced the plugs just to make sure but it's no different. Could I have a bad coil?
The bike starts and runs perfectly until I up the revs or grab a big fist of throttle.
Anyone have a spare coil I can buy to try and isolate if that's the prob. Could it be a bad ecu? The spu has been replaced previously.
Thanks In Advance for any help/thoughts
 

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Hi guys, hoping the brains trust can guide me with my issues.
My 750 had a 42k service 1500 kms ago. As I commute I hadn't revved it much but in a spirited ride the other day I discovered the bike wouldn't rev past around the 9000 rpm range. Occasionally it would get to 10ish but wouldn't hit redline.
Hoping it was something simple I replaced the fuel filter. Prob remains and is gradually getting worse. Now it's struggling to get past 6000.
All fuel lines looked fine.
I've replaced the plugs just to make sure but it's no different. Could I have a bad coil?
The bike starts and runs perfectly until I up the revs or grab a big fist of throttle.
Anyone have a spare coil I can buy to try and isolate if that's the prob. Could it be a bad ecu? The spu has been replaced previously.
Thanks In Advance for any help/thoughts
Hi Luke.
If it was a coil mate, the bike would run on 3 cylinders or worse.
When you replaced the fuel filter, did you clean the strainer on the pump ?
Check the O-rings on the fuel lines for swelling.
 

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Discussion Starter #3
Hi Dons,
I'll have another look tomorrow. In my haste to do the filter, I noticed the strainer for the pump but couldnt see how to remove the pump to get to the strainer. I also used a non-standard filter (had correct inlet/outlet diameter but is a larger cannister in size over-all) - would this add to my probs? I guess I better slow down and look more carefully at the items you have suggested. Is there a trick to removing the pump?
 

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Luke, I have an ecu you can try, also have two different fuel filters that are know to work ok.

Where abouts in Sydney are you ?
 

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Discussion Starter #5
Hi mate,
I'm on the south side (the bubble)

Think my ecu is ok but would happily buy a fuel filter off you.
I work at the airport if that's any closer to you

Cheers
 

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My money is on degraded fuel lines or a blocked filter. Even though you just installed a new one, I would take the fuel pump assembly apart and check for degraded lines. Or you had some grunge in the old filter and when you removed it, some escaped into the fuel lines and now the injectors are clogged.
 

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Luke, I'll bring one to Pyrmont with me, can you get there during office hours ? I might be able to get over to the airport one day this week if not. Email me your details, my email is on my profile.

Cheers
Rich
 

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? no fuel?

I'm with Carl and Donsy;
check your fuel lines (to be replaced every 3 years)
and the prefilter screen, I have pictures of one light barely goes through......the tank had pieces of rubber floating around that were being trashed by ethanol?

you could see them floating but you couldn't feel them
 

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Discussion Starter #10
Thx guys. More investigating this weekend hopefully. I'll report back any findings. Cheers
 

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Discussion Starter #11
Guys is it possible to have a bad fuel pressure regulator ? How does that regulator come out? Cash can I buy some more quick release fittings off you still? Lastly are the fuel pump reliable? I can hear it priming but could it be failing to provide adequate pressure under-load?
Thx all
 

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Anything is possible Luke, all depends on how much money you would like to throw at it.
Pull the pump plate again, gently wiggle the fuel pump out of the rubber housing and clean the strainer. If you find nothing, then it's time to look elsewhere I recon.
 

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Also

Anything is possible Luke, all depends on how much money you would like to throw at it.
Pull the pump plate again, gently wiggle the fuel pump out of the rubber housing and clean the strainer. If you find nothing, then it's time to look elsewhere I recon.
Might be a good idea to have those injectors cleaned too.
Are you still using the original fuel lines Luke ?
 

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Discussion Starter #14
Pump strainer has been chkd and cleaned for good measure. New filter went in today. I looked at the lines while doing it and although they looked a bit old, there was no visible cracking etc. I will replace the lines just in case. I found some small hard clear plastic pieces in one of the quick disconnect couplings and removed it. All went back together and the bike was as bad as before. Starting to get really frustrated hahaha. Although I am getting damn quick at tank removals etc
 

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Okay, a bit weird about the little plastic parts in your system. Might be a good idea to get those injectors and the injector rail off, just to see if nothing is blocking it.
 

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Discussion Starter #16
Hi guys, just an update.
New lines went in and all fuel connections/ manifold and injectors were cleaned with compressed air.
The bike is back to its hard-revving self.
Thanks so much for all the ideas and advice
Cheers
 
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