102 replies to this topic

[Snorvey]

Morning all.

I think my vacuum fuel pump is fudged. Turning the motor over, the fuel flow is very weak (barely a dribble) and sometimes non existent. I think this may be at the root of my poor starting issues.

So I'm looking at fitting an electric fuel pump. Scanning the excellent research on here, it seems that a second hand part from the carb model R1/R6 is the one to go for - at around fifty notes + del.

But just typing in 'motorcycle fuel pump' brings up this brand new 'universal' fuel pump from the US for around £29 inc del (although they'll nae doubt stick another twenty notes on for 'delivery to the highlands of Scotland' :-)

http://www.ebay.co.u...#ht_2521wt_1185

This is a brand new fuel pump for your carburated vehicle. This pump will work on any vehicle with a carburator and under 260hp. Has a 2 bolt mount attached with a bolt spacing of 2.25-3.3 inch to allow easy mounting. The inlet and outlet have a 5/16 barb for 5/16 fuel line. Output pressure is about 3-5 psi. 12volt 90lph output.

Any thoughts?

Cheers


Snorvey

[jdelfino]

I'm ready to order one like this: http://www.motorcycl...-Fuel-Pump.aspx

to me the electric pump put to much pressure on carbs not design for it.. but i might be wrong..

[openroad]

I'm ready to order one like this: http://www.motorcycl...-Fuel-Pump.aspx

to me the electric pump put to much pressure on carbs not design for it.. but i might be wrong..

i've just fitted a after market r6 fuel pump. http://www.ebay.co.u...=item20bfe8c58f. i've found that it was pumping to much fuel and had to adjust the floats and got to adjust the fuel mixture but should work alright once that is done

[Studley Ramrod]

As a rough comparison, the mk2a fuel pump output pressure is 0.07 bar or 1psi.

Can't really say if the pump would be ok or not Snorv, might be ok if the float needle valve's/seats are in good condition.

Given that a new vac pump would probably last another 20yrs, might be worth sticking with a mechanical wan if the price is acceptable.

[Snorvey]

Given that a new vac pump would probably last another 20yrs, might be worth sticking with a mechanical wan if the price is acceptable.

You're probably right Studley (as usual )

I'll have a hunt around and see what they're going for.

Cheers

[dapleb]

OI loike the Snorv style thunkin in this ear thread. A common problem with the mechanicals is that the diagonal-flam plastic thingy stretches and flaps in the breeze. If this is the case with yours, someone ear repaired his wid a piece of petroleum resistant plastics sheet stuff. Someone also suggested trying overheadprojector type material or summat too. ....how thats for a Snorv fix hey?

[Snorvey]

Morning Dap

If this is the case with yours, someone ear repaired his wid a piece of petroleum resistant plastics sheet stuff. Someone also suggested trying overheadprojector type material or summat too. ....how thats for a Snorv fix hey?

I didn't realise the pump was servicable to be honest! I'll take the pump off the the weekend and have a look at it. I think Studley's right though, 2-3 psi might be a bit extreme compared to the later TDM pump.

I'm right in saying that when you turn the engine over it should come out at a fairly reasonable rate eh? I'm hardly getting anything.....

Cheers

[Studley Ramrod]

Yep, a fairly reasonable rate

Afore ya go spending yer hard earned, you could check the pump casing screws are all nicely tweaked up. Also check the vac pipe that runs from the pump to the carb inlet stub for splits, you'll prolly notice the pipe is a t**t to pull off the inlet stub as it tends to go hard and can crack/split. Best to snip off the crusty bit and refit

If you then decide to investigate the pump internals, be careful when splitting the pump halves as you could damage the diaphragm.

[Snorvey]

Here's hoping the weather's a bit crap for the bank holiday weekend - cos I know what I'll be doing!

[Snorvey]

£25 plus postage for a working fuel pump (albeit a 20 year old fuel pump!)?

http://www.ebay.co.u...5#ht_1272wt_952

I wouldn't say it was worth anymore than a tenner. Then again, upon reading the Haynes bible last night it say that the although the fuel pump can be opened for inspection, none of the parts are replaceable - so I guess it's worth whatever folks are prepared to pay for it.

Daps, are you pretty sure acetate sheet will work? WH Smith sells the stuff in packs - I only want one bit!

I guess Yamaha must have used some sort of material in the pump, it's just a bugger finding out exactly what it is!

[Studley Ramrod]

Have a look here Snorv http://www.carpe-tdm...p;hl=laminating

[Snorvey]

Thanks Studley

I'm off up to Tesco later on so I'll see what they have in the stationary isle.

Tomorrow I'll dunk it in some petrol for a good few days and see if that does the job.

Cheers

[Snorvey]

Well a little digging around on wiki led me to a page on fuel pums > diaphragm pumps > thermoplastics > cellulose acetate > cellulose triacetate...

This tells me it is used as a film for Overhead Projector Transparencies and is.....Resistant to grease, oil, aromatic hydrocarbons, and most common solvents

http://en.wikipedia....age_Scenarios_2

four quid from WH Smith

[dapleb]

Bloomin marvelous. If ya can wait a week or so oil send thee some Snorv.

[Snorvey]

Bloomin marvelous. If ya can wait a week or so oil send thee some Snorv.

Just read your post dap....picked some up in wh smith earlier on. I'm dunking it in petrol tomorrow and if
It don't work, oil be in touch!

Cheers!

[MadAd]

Know it a little late as you are already sorted.
I use an electric fuel pump on my race bike.
It's a Facet posi flo pump and it works a treat!!

[Snorvey]

Well the membrane is out and sitting in front of me as I sup my coffee. It looks ok, to be honest - quite concave (or convex depending on your viewing angle!), so I guess that means it's stretched. It looks very similar to the one in the photo in the repair thread.

I've got a piece of the OHP material I bought yesterday sitting in a joog of petrol and I'm away to cut a replacement bit out soon.

I wished I'd paid more attention when I'd split the pump, but the gasket was wet with fuel - I suspect that it came from the petrol as the pump came apart - there were certainly no signs of any leaks whatsoever when it was on the bike.

Unfortunately, I don't have any replacement gaskets to put the pump back together with, so the old ones will have to do.

There were 2 slack-ish screws and 2 very tight ones, the rest were tight enough. The screws were well lubed with copper grease, so I don't know if that means that someone has been into it before me?

Right, onwards and upwards!

[Studley Ramrod]

Nice wan Snorv ! Removing the diaphragm intact means you can always plonk it back in if the diy jobby don't perform for some reason.

Happy pumping !

[Snorvey]

I was going to let the diaphragm soak for a few days, but it stared raining, so I thought I'd plod on with it.

Cutting the shape was no problem at all, but I couldn't find anything suitable to punch the holes for the retaining screws. Until I found the wifey's old hole punch from her school days ( a long time ago!)

From then on, it was no problem and being impatient as I am, fitted the new membrane and reinstalled the pump. A quick test and it is hosing fuel out of the exit pipe (rather than the previous dribble).

Then I attempted to fire it up. No joy for the first turn. Although I have the optimate on it, I decided to hook up the power pack too....barely a whirrrr later and she fires up no problem! Fantastic. And no backfires on the right cylinder either. She revs beautifully too.

I'm sitting here listening to her burble away and the fan has just kicked in. The shed is full of reek, but I don't care.....

I'm still going to soak the OHP material for a few days, but it seems we are sorted.

Cheers all



D

[dapleb]

Nice wan Snorv. Gonna give it a whirl me'sen at some point. Def sounds loike someone has beed in there afore thee. Ya could mek yer'sen some new gaskeetos, now ya have the'ole punch n'all.