Number of holes doesn’t affect flow-rate, just atomization. Were these new factory OEM injector from authorised dealer?

Many other things affect fuel-delivery:

• fuel-filtre
• air filtre (less air for same fuel amount = too rich)
• FPR , verify adjustment vacuum signal is correct, it reduces pressure to match air-flow
• MAP-sensor and vacuum signal. leaks will cause ECU to think load is higher and inject too much petrol
• TPS sensor adjustment position and output voltage, ECU uses alpha-N blending algorithm

You cannot just replace parts to fix problems. There are adjustments that needs to be done. For that, you need to measure and test to get numbers. Somewhere, some place, there is a number on bike that doesn’t match what manual says it should be.

 

Thanks for the info. As mentioned I found Peivso injectors which supposedly match based on the honda part number with the only visible difference being the number of holes . I guess there is a good chance that they are defective. As far as I have found there are no other options for new injectors. To solve the problem I cleaned the old injectors and put them back in, the bike ran well for a few months (indicating that all the other parts are functioning correctly) but unfortunately a slight misfire has returned on one cylinder. I'm 90% sure its the injectors so short of cleaning them up again I was hoping to to just replace them with a good alternative or at least find a way to properly test the injectors before replacing them again.

 

again, many variables and you need to measure them all
right now you are just guessing because you have no numbers
you might have corroded wiring terminals and unplugging and replugging injector connector may clean them so bike runs well for short time

test and measure injectors 1st to know their actual flow rates
measure before and after cleaning

another common cause of stumbling is cracked leaking vacuum line. When you change injectors, you touch and move vacuum lines. This may help them, seal for short time. Then with vibration, they leak again after short time

one of these hoses go to FPR and adjusts fuel-pressure. Need to measure fuel-pressure

 

I have delt with hundreds of OEM Bosch style injectors, and outside of very obvious physical damage I have never seen one go bad, so I am not sure why I keep seeing people try to replace them without VERY obvious proof they are bad. If you want to do anything to them yourself, just run them through a sonic cleaner.

Also fuel injectors for a specific application flow a VERY specific amount of fuel, and injectors in general have a HUGE range. So replacing them without knowing exactly what volume yours flow and what the replacements flow is like picking a random jet size for a carburetor that happens to screw into the same size hole then wondering why your engine doesnt run right after replacing the main fuel jets for a 200hp engine with those from a 7hp push mower.

 

Bosch makes good injectors, back in the old days we were getting remans from Napa that were Bosch, never had a lick of problems from them

 

Also proper way to clean injectors is to back-flush them in reverse. That's because petrol passage gets smaller and smaller as it goes through injector.

If you push cleaner fluid in same direction as petrol flow, it will just push clogs tighter and tighter into smaller opening. Need to push clogs backwards from tip to inlet of injector to get them out. Toyota makes good injector cleaning-kit that pushes in reverse flow.

And again, you must measure actual flow-rate of injector before and after cleaning to know if it did any good. Without numbers, you're just guessing.

 

Here is some feedback on this, thanks for all the comments and suggestions. The injectors were definitely clogged. I built a rig to test the flow and found that they we all different. I have since done lots and lots of cleaning to try and get the flow on each to be the same and have ended with three that are the same and one that has slightly more flow suggesting that it is bad. So it looks like I'm going to need to replace at least one. I also tested the flow rate on the Peivso injectors which are supposed to be a match for this bike and found that they were letting through almost double the amount so definitely not a match.

 

Good job with measuring flow and cleaning.!

Did you happen to capture debris that came out? Might look info getting better filtre after pump.