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Discussion Starter #1
I wonder if anyone could shed some light on the issue i recently picked up with my 2000 MODEL MV AGUSTA F4 750 " 2089 km on the clocks "
Bought the bike from a collector who used it for desplay purposes , hence the low km ,
I was riding last weekend and she just would not rev past 8000 rpm , carried on riding for another 100km or so , hoping it would clear , but it just stayed below 8000 rpm ,
after refueling , i noticed she was struggling to pick up rev's while riding , and started spluttering , farting and missing , at this stage she would not rev past 4000 rpm ,
eventually she cleared back to 8000 rpm and I made my way home ,
I have checked and replaced the plugs , with OEM parts," NGK CR9E " plugs , she is still not running properly ,
cyclinder no1 is running cold ,
could this be injector problem ?
 

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Hi Waren.
Welcome aboard mate.
Long story made short. You have to check or/and replace the fuel lines at the very least. Have you got a pic of your ECU, sounds like you might have a Japanese restricted ECU in there.
 

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Maybe this isn't it, but the bike has clearly been sitting for quite some time so perhaps there is some "varnish" in the system if any gas was in there. At this point I don't believe Stabil-Gas (used here in the USA, don't know if it's available in Australia or South Africa) will help. However, one killer product that recently hit the market in the USA is Star-Tron. It will clear out these varnish and residue problems very quickly (usually within 20 miles or so). Here is a link to the product:

http://mystarbrite.com/startron/

From the web site I see they do have international distributors in South Africa, so you should be able to find it. An 8 oz bottle is about $10 here, and you only need about 1-2 oz per tankful. Using too much of it is not an issue because it is combustible, so you may want to use more than the recommendation for the first go at it. Given the history of the bike, I would just try this first to rule out the possibility that this is the only problem. This stuff works so well, I heard from an auto parts store that the Stabil-Gas sales reps are freaking out. Good luck!
 

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The fuel systems designed to keep the lines full when off, so even if the tank was drained when it was stored the lines and inline filter (in the tank) would still be full, possibly gumming up the filter and injectors.

I'd change the filter and run some injector cleaner through it in the first instance.

Si
 

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Discussion Starter #7
Thanks for the feedback , what I have forgotten to mention was that when I purchased the bike , it had 190 odd km on the clocks , the bike stood , fuel was not drained , when I got the bike I sent it in to the local mechanic to strip and clean ,
I have been using injector cleaner mixed into the fuel , and have done about 1890 km hassle free , I am also leaning towards the suggestion that it could possibly be the injectors that might be blocked.
 

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Thanks for the feedback , what I have forgotten to mention was that when I purchased the bike , it had 190 odd km on the clocks , the bike stood , fuel was not drained , when I got the bike I sent it in to the local mechanic to strip and clean ,
I have been using injector cleaner mixed into the fuel , and have done about 1890 km hassle free , I am also leaning towards the suggestion that it could possibly be the injectors that might be blocked.
i put seafoam in my gas tank and coincidently two of my injectors got blocked completely
 

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It would be prudent to change the fuel filter,internal fuel lines and the lines to the tank. There is also a gauze screen at the base of the fuel pump module which it would be sensible to clean.. Also whilst at it swap the plastic quick connectors for metal ones from CAG on here. The plastic ones are known to crack with age/wear .

Check the airbox to velocity stacks rubbers...Service the air cleaner.

and I would also clean the inside of the tank out..

She's worth it ; )

joe
 

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Have a look ig the breather in the fuel caps not blocked. I had this problem once when I swapped to an aftermarket cap, this blocked the breather and the bike felt as if it hit the rev limiter at about 8K.
 

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Hi, just had virtually same problem, bike would not rev past 4k. Changed fuel filter and internal pipes, now perfect. Had just bought bike. The fuel filter and pipes had not been changed from new ! Inside of tank was very clean , I think the fuel goes to jelly when left.
 

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Discussion Starter #12
Ok , so all things are leading to a blocked injector , i swopped injector " No1 " the pot that was running cold , with injector " No 4 " and found that No 1 ran and got hot , while pot No4 then ran cold ,
Taking injectors in today to get them all checked and cleaned.
Opened tank and found loads of crap had built up at the bottom of tank , cleaned tank out really well , and will be getting a replacement fuel filter this morning.
Have cleaned the air filter , " BMC " so thats all sorted.
will put bike back together this evening and let you know how it runs ,
Thanks for the input you guys have given
 

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When you put the tank back on, check you don't pinch or crush the fuel lines. I've done that before now and got a similar issue as you were having ;)

Oh, and do what Donsy says and check the breather hose is clear.....
 

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Discussion Starter #15
I am from the " windy city " Port Elizabeth ( South Africa )
Will do a thorough check before putting bike back together,

Thanks again
 

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Discussion Starter #16
Ok , so cleaned the injectors last night , changed fuel filter in tank , gave tank a good clean inside , and hey presto , , , , , , , , Bike is running like a dream again :)
 

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Ok , so cleaned the injectors last night , changed fuel filter in tank , gave tank a good clean inside , and hey presto , , , , , , , , Bike is running like a dream again :)
Cool, now add some pics. I've got a couple of friends here in West Aus, from East London and PE.
 
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