Author Topic: ST100 FUEL PUMP  (Read 2389 times)

Offline RCMCY

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ST100 FUEL PUMP
« on: June 17, 2014, 10:46:53 PM »
Have been having trouble with ST1100,s running rough and missing on front right hand cylinder (it must be the last carb to get fuel) one had been giving trouble for ages and changed carbs ignition unit etc but after doing the pump runs perfect, I have done half a dozen bikes all fixed the rough running.
The fix, you can put an aftermarket pump as has been posted before, but I have found the existing pump can be repaired. (the good part is it costs nothing)
After removing the original pump I have not been able to get the end off whith out slitting the cover but then with the armature out clean the comutator with some fine sand paper and reasemble fixes the problem.
There dosen,t appear to be anything wrong the armature looks okay but obviously must have a film over it.
Don,t know how long it will last but my ST has now covered 10,000klms since and is still going perfect.
There is a discription on the American ST site on how to do it (as always found after I fixed it.)
Cheers
Ron Hewitt
 

Offline Pezzz

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Re: ST100 FUEL PUMP
« Reply #1 on: June 17, 2014, 11:24:52 PM »
 ++
Thanks for the tip.
Pezzz
:wht11
FarRider # 730
 

Offline johnnyYTED

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Re: ST100 FUEL PUMP
« Reply #2 on: June 18, 2014, 07:56:46 AM »
 :dred11
  :thumb I'm hoping I don't need this info for a long time  :eek but great info to know, thanx Ron.
:clap  :hatwave ++
Picton  if it doesn’t flood higher than previous times.
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STranger 1998 ST1100, x Police
STrangler ST1300 2007 Charcoal Grey.
BEEstY 2017 Can-Am Daytona 1330.
maybe something with a little extra
:dred11 :Spyder
 

Offline Yorkie

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Re: ST100 FUEL PUMP
« Reply #3 on: June 18, 2014, 08:57:27 PM »
From my experience with armatures this will only be a temporary fix, the commutator needs to be undercut, that is putting a sharp point on an old hacksaw blade and cutting away the white insulators between the copper segments. The problem is caused by the soft copper wearing leaving the insulator sitting proud and preventing proper contact with the brushes. 
Brian 0418937173
Manager York Motor Museum

In the shed
1999 ST1100A
1971 CB750K2
1980 XV750
1977 GL1000
FR#720
CMRCWA #133
York,WA

So at what age does this "old enough to know better" kick in?
I believe in the "hereafter", every time I go to the shed I have to think "what am I here after"