Hello, Been hiding out. Have any of you tried the Amazon/Ebay fuel injectors? If so what kind of results did you have?
Thanks

Since they could come from any number of different suppliers when sourced from fleaBay or Amazonium, 'results may vary.' 

I use Dr Injector - with locations around the US. You send them off, or visit a location, and they arrive back to you 'as new' with new o-rings and a chart showing their vitals before and after. $128 was what I paid for four a few weeks ago. They even do GDI injectors (high pressure, direct injection) for a bit more.

The one in Federal Way, Washington is my go-to.

Hi there,

I bought these injectors (see picture) 4 years ago from eBay. The idea was to have the original injectors restored (new paint, seals, filter etc...) and in the meantime drive with these cheap ones. To be honest, these have worked really well for about 20,000km already. So well, in fact, that I haven't even thought about the originals anymore. JHparts shop at eBay sold these and advertised them as being suitable for the BMW K100. 

I just did a half Finland tour with my K100RS (2500km) and fuel consumption was about 4.2 - 4.7 litres per 100km depending on the day trip (highway 100-120km/h, country road 80km/h or/and city roads 40-60km/h). Normal consumption in a city seems to be around 4.7 - 4.9 or even higher. These readings may vary slightly due to how full the tank was refuelled, so not scientifically accurate readings.

I've bought also such injectors in blue plastic.
Some were supposed to be remanufactured Bosch injectors, with a plastic body frame instead of the steel OEM body. You say so...
Anyway; two K100 of my cheptel are running OK with them, yet being a bit too rich. I tried to run similar on another and it never worked well...

Thanks for the replies. I think I will give them a go.(Roll the dice) I have a couple that are not acting correctly.

Bill

I've used Mr. Injector more times than Bruce Willis has been in a B movie and have always had good results.

Link: https://www.mrinjector.us/

BMW designed the  K100/K75 engines to run on single hole injectors. The single hole injectors are designed to spray onto the head of the inlet valve to cool it and to break up the spray. There is no benefit to be gained from fitting 4 hole injectors. Any benefits could also be achieved by fitting clean single hole injectors. I have yet to find a Dyno report showing the benefits of 4 hole injectors compared to single hole injectors. 4 hole injectors can also be more prone to fouling due to the smaller orifice sizes.
Regards Martin.

It's been my understanding that 'upgrading' to four holers might get you better atomising of the fuel droplets, allowing cleaner combustion. 

I can't imagine the raindrop from a single holer stands much of a chance - as compared to being broken up a bit beforehand - whilst being sucked into that swirling, pumping mass of metal and air, only to be unceremoniously blasted to smithereens and mashed into the cylinder head and pumping piston crown, before getting booted out the egress hole into a sooty tailpipe, then sent backwards down the road like a circus clown fired from a cannon.

Gasoline is not injected directly into the cylinder. It's injected into the cylinder head and atomizes when it hits hot metal before the valve opens.

For some reason the guys on Jeep forums are infatuated with the four hole injectors - like oil threads.

Put "four hole injectors dyno" into Google. Like Martin, I've never been able to find a single dyno comparison (i.e. empirical objective data) despite this being a long hashed over topic.

I've tried them in both 2V and 4V K bikes. No difference on the butt dyno or mileage.

Hint: But if you put magnets on the fuel rail to align the fuel molecules then you will get better combustion.

There is no tongue-in-cheek emoji. That might look like a face choking on its lunch. 

I too was lured by the myth of 4 hole injectors and nearly went over to the dark side. I was saved by my mates son who was a injector specialist. He explained that the spray was designed to hit the back of the valve break up and cool the valve. I ended up building a rig to clean and test my injectors after been disappointed with a professional clean. Seat of pants Dyno confirmed improvement. Most reports of improved performance due to fitting 4 hole injectors could have been achieved by fitting clean single hole injectors. If I was selling 4 hole injectors as an improvement I would be doing a Dyno comparison to show the benefit.
Regards Martin.

I have been playing around with K bikes since 2010, buying more and more and not selling any of them and had lots of fun with injectors too.

So I have run 2v engines with both original and replacement injectors, single hole and 4 hole.

Any time I put 4 hole injectors in my 2V Ks, I get an increase in fuel consumption. When I put the single hole injectors back, I get a decrease.

My reckoning is 5-10% and have extended periods to see the results. However I figure the 4 hole are more responsive.

You'd probably get similar results from new single hole injectors without the fuel usage increase. A dyno comparison would confirm your findings.
Regards Martin.

MartinW wrote:You'd probably get similar results from new single hole injectors without the fuel usage increase. A dyno comparison would confirm your findings.
Regards Martin.

I did think that, having found a big improvement when I first put in the brand new 4 hole injectors. However after about 3,000 miles I swapped them back out for a refurbed set of single hole injectors. Fuel economy returned but it came with a slight loss of responsiveness.

I am currently looking at my Sprint K100 [early 1984] having just done the oil pump and a brand new old stock heat shield makes the injector rail look a bit crappy so its next.

Thanks for all the input! I have ordered a ordered and received a set of single hole injectors. Will install and see how they work. Am going to send the originals out to be rebuilt. Will report on these injectors.

Thanks again!
Bill