Yamaha engined golf buggy - Mikuni petrol pump

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Tue 20 Jan 2015 21:34
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

I've a Mikuni petrol pump that's defunct. It's off a Yamaha engined golf buggy. It's powered by the pressure difference in the crankcase that pulses a diaphragm in the pump. That pulses a diaphragm that pumps the fuel via a couple of non-return valves.

I've spent the best part of today figuring out how the damn thing works and deciding that one of the non-return valve's stuffed.

I've taken it apart several times and by blowing down the outlet I can detect air coming out the inlet by placing the inlet in a tub of water and detecting bubbles.

I've searched Amazon and ebay without success.

Anyone suggest where I might find a replacement?

Photo's attached:

s1102.photobucket.com/user/bathtubshare/media/DSCN...l

s1102.photobucket.com/user/bathtubshare/media/DSCN...l

Edited by bathtub tom on 20/01/2015 at 21:36

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Wed 21 Jan 2015 10:06
Yamaha engined golf buggy - Mikuni petrol pump - madf

Ebay US?

www.ebay.com/bhp/mikuni-fuel-pump-kit

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Wed 21 Jan 2015 15:20
Yamaha engined golf buggy - Mikuni petrol pump - Railroad.

Is this an EZ-GO buggy?

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Wed 21 Jan 2015 16:01
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

Is this an EZ-GO buggy?

To be honest I don't know, I didn't look. I won't be seeing it again for a week or so, I'll try and find out then.

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Wed 21 Jan 2015 16:33
Yamaha engined golf buggy - Mikuni petrol pump - Railroad.

EZ-GO are a Textron company, along with Ransomes Jacobsen who make grass cutting equipment, and have a UK base in Ipswich.

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Wed 21 Jan 2015 23:58
Yamaha engined golf buggy - Mikuni petrol pump - focussed

The uk importer for Mikuni appears to be:-

www.allensperformance.co.uk/products-mik%20fuel%20...l

Try them.

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Thu 22 Jan 2015 17:51
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

The uk importer for Mikuni appears to be:-

www.allensperformance.co.uk/products-mik%20fuel%20...l

Try them.

I did, they haven't replied.

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Thu 22 Jan 2015 23:35
Yamaha engined golf buggy - Mikuni petrol pump - focussed

Ok forget the Mikuni brand - try Walbro, these pumps get used on lots of 2T garden equipment and karts use them as well.

www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2...0

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Thu 22 Jan 2015 23:53
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

That looks interesting, thanks. Does a golf buggy really need a 'racing type' fuel pump?

I've a few more enquiries ongoing. A plastic bodied alternative's looking promising at the moment. Cost is important for the user!

I'm amazed at the claimed pumping capability of these things. The lowest I've seen's 15 litres/ hour. That's three gallons/hour! I reckon I'd have to be doing over the ton in my current car to use fuel at that rate! This is for a golf cart!

I found the US website for what looks like the manufacturer of these carts and they want $77 for the pump + postage + VAT. On arrival in this country, that's looking close to £100.

Found numerous, universal, electric pumps on ebay for less than twenty quid.

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Sat 24 Jan 2015 12:24
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

Allens performance got back to me and it looks like they can do a replacement for around thirty quid.

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Sat 24 Jan 2015 20:43
Yamaha engined golf buggy - Mikuni petrol pump - focussed

It sounds like your are sorted with Allens, technically, don't fit an electric pump to a two stroke, it will generate a higher pressure than the carb float needle will be able to shut off- the crankcase-pressure operated pumps don't generate very high pressures, about 1.5 to 2.0psi and when the float needle shuts off at idle the pump just stalls and stops delivering, some of the high output 15 to 20 gallon per hour types on high hp 2T outboard motors have built in pressure relief valves to prevent carb flooding.

Edited by focussed on 24/01/2015 at 20:44

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Sat 24 Jan 2015 23:02
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

>>don't fit an electric pump to a two stroke

AFAIK it's a 4-stroke. It sounds like a 4-stroke (when it's running) and I can't see any separate oil tank.

I've re-furb'd an old SU pump that I considering fitting, but haven't a clue as to its output pressure, so was holding back. I'd also have to fabricate a mounting bracket, fettle the fuel line connectors, find an appropriate electric supply, etc

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Sun 25 Jan 2015 22:56
Yamaha engined golf buggy - Mikuni petrol pump - focussed

Strange-never seen a crankcase vacuum operated fuel pump fitted to a 4T.

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Mon 26 Jan 2015 10:09
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

I may be wrong, but it doesn't sound like a 2-T to me, it also revs very slowly. I'd thought a single cylinder 4-T would have very strong crankcase pulses, making it ideal for this type of pump.

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Mon 26 Jan 2015 11:49
Yamaha engined golf buggy - Mikuni petrol pump - Railroad.
I've worked on a lot of golf buggies both electric and petrol driven. I've never seen one with a two-stroke engine. Most of them cut the engine off when the throttle pedal is released, and restart when the throttle is depressed again. Golfers would get annoyed with idling buggies putting them off their shot. The throttle switch and cables usually take a bit of setting up to get right. This isn't difficult but it can be a bit fiddly.
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Mon 26 Jan 2015 12:30
Yamaha engined golf buggy - Mikuni petrol pump - bathtub tom

When this one's running, it's got the habit of a backfire just as the engine stops. Wouldn't be very welcome on a golf course.

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Mon 26 Jan 2015 13:29
Yamaha engined golf buggy - Mikuni petrol pump - Railroad.
That's exactly what happens when the throttle arrangement isn't set up correctly. It's not so easy to explain, but it becomes obvious when you do it.

The switch is on the throttle pedal and must not switch off until the throttle butterfly valve is at the idle position, which also must be correctly set to allow the engine to idle at the correct speed. Temporarily bridge the switch contacts so that the engine doesn't switch off. Then adjust the throttle stop so that a nice even idle speed is achieved. Adjust the cable so that the throttle moves through its full travel, but leave a bit of slack at the top of the pedal so that the ignition can be switched on without any throttle opening. When it's set correctly the engine will return to idling with your foot only slightly touching the pedal, and the last part of the pedal being released will shut the engine off. If it's all set correctly your backfire will not happen, and the buggy will be a lot smoother to drive.
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