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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: petermarek on March 10, 2016, 08:05:32 AM

Title: Fuel Pump WHINE!
Post by: petermarek on March 10, 2016, 08:05:32 AM

I have a 1985 K100 RT I've resurrected the summer of 2015 from a "CarPort Find".

The gas tank was clogged with dissolved rubber from the years of sitting. I cleaned it all up but had to replace the fuel pump (and all the hoses and filter). I am CHEAP, so I went with an aftermarket Bosch look alike fuel pump - HFP-437 Motorbike Intank EFI Fuel Pump ($70).  :dunno

I have nothing bad to say about the pumps reliability or durability....BUT it is so loud in the tank that it buzzes my helmet even at speed. After > 3k miles I've had it.

Thus the question: Is the OEM Bosch Pump Quiet? Do you hear it when the bike is running?

Title: Re: Fuel Pump WHINE!
Post by: johnny on March 10, 2016, 08:23:35 AM

greetings...

ear plugs...

j o

Title: Re: Fuel Pump WHINE!
Post by: tsnap on March 10, 2016, 08:47:54 AM

i RAN INTO A SIMILAR COST PROBLEM YEARS AGO ON A sAAB FUEL PUMP, DISCOVERED A CROSS REFERENCE TO A vw rABBIT PUMP FOR 1/3 THE PRICE.  wAS WORKING FINE WHEN I sold the car.

Heres what I found online search.  I use purolator stuff a lot.
http://www.motobrick.com/index.php?topic=2058.0

this is for a K1100, but htere is a lot of options on googling around.

tom

Title: Re: Fuel Pump WHINE!
Post by: johnny on March 10, 2016, 09:20:10 AM

greetings...

if it is a 6 volt pump it will be running twice as fast...

j o

Title: Re: Fuel Pump WHINE!
Post by: tsnap on March 10, 2016, 09:36:43 AM

if it is a 24 volt pump it will be running halfast.

 :falldown:

to.......m

Title: Re: Fuel Pump WHINE!
Post by: petermarek on March 10, 2016, 09:51:18 AM

Ear Plugs for sure....but those are need regardless! Mines a VERY early RT; manufactured 11/14/1984!

I believe it's a 12 volt pump....I'll check - If it is 6 volt, that would explain a lot!

I did install a new BMW OEM Damper and collar with the new aftermarket pump. It seems to be isolated from touching surrounding metal mounts.

Does anyone actually have a Bosch Pump? I've read about folks having to put their ear on the tank to ensure they are getting fuel when debugging a non-start. If the extra ~$300 gets me that level of volume, I'll consider it.

I expect the normal K Bike rattles and buzzes  :bmwsmile

Thanks

Title: Re: Fuel Pump WHINE!
Post by: K1300S on March 10, 2016, 10:11:50 AM

My stock bosch pump makes almost no noise.

Title: Re: Fuel Pump WHINE!
Post by: johnny on March 10, 2016, 10:14:56 AM

greetings...

bagster tank cover... that will block some noise...

j o

Title: Re: Fuel Pump WHINE!
Post by: Laitch on March 10, 2016, 10:43:33 AM

Marshall's post has given us the benchmark for OEM performance in his K75 so here are comments (http://www.motobrick.com/index.php/topic,2058.msg14200.html#msg14200) eerily descriptive of your aftermarket situation, peter.