Comparison of AFR Original Chinese Knock-offs vs Genuine Bosch

Since I still have the WEGO AFR measurement and display system hooked up on my 2014 Commando Sport, I decided to replace the Chinese Bosch copy injectors with genuine Bosch injectors, just to see if there were any differences. It wasn't because I had any real problems with the orignal injectors, but I had noticed that the right cylinder was running leaner than the left cylinder in most of the fueling map, and wondered if it might be the injectors. It doesn't appear to be the injectors, and I didn't see the Bosch injectors as working any "better" than the originals. The pictures below show some of the results.

This is a comparison of the difference between left and right AFS during a typical ride. In the top chart, showing AFRS with the original injectors, you can see that the right cylinder (green trace) is generally leaner than the left cylinder (red trace). In the bottom chart, showing the same but with Bosch injectors, it has switched to the left cylinder being leaner. Maybe that's just how much random difference there can be in a pair of injectors.

You can ignore all the vertical spikes to the 19.5 AFR level. That's just the ECU shutting the injectors off during over-run throttle closing.




When I look at the tabular AFR display produced from processing the raw data above, the tables below show the same switch from lean right cylinder to lean left cylinder. These tables show AFR vs RPM and throttle position, and are produced by the WEGO software processing the raw data, including filtering for consistent measurements in each cell. First one is for the left cylinder.



And the same for the right cylinder



The most interesting result the tables show is that the with the Bosch injectors, both cylinders are running much leaner than with the original injectors.

That's kind of a PITA for me, because I've just finished tailoring the fuel map in the ECU to suit me, and if I leave the Bosch injectors in, I'll have to go back and log enough data to do it all over again.

Anyway, I thought some of you might find the info interesting.

Ken

For anyone interested in the WEGO details, this is my original post when I started using it.


Ken

Hi Ken, I was thinking of lookin at the injectors but not sure what mine has? Is there any marking on them to show if genuine Boshe? I was out on it yesterday around the rock store and Canyons and man it fuels so well I dont think I will mess with it. Out of curiosity how are you acessing the ECM? do you have software and leads at your place?

Hi Ken , Very interesting . A while back you mentioned wanting to get a bit better fuel mileage . Did you manage to do it ?

Canyon Motorcycles said:

Hi Ken, I was thinking of lookin at the injectors but not sure what mine has? Is there any marking on them to show if genuine Boshe? I was out on it yesterday around the rock store and Canyons and man it fuels so well I dont think I will mess with it. Out of curiosity how are you acessing the ECM? do you have software and leads at your place?

Click to expand...

The story on the injectors is that some of the earlier 961s came with genuine Bosch units, but that the factory later switched to copies. There is a good bit of info on-line explaining how to tell the difference, and Bosch has a pretty serious department to deal with counterfeit copies. Bosch has posted some detailed info on-line telling how to identify them. Matt at SCS said they tested the copies Norton used, and they seemed to perform properly. I only tried switching because I was curious about the difference I was seeing between left and right cylinder mixtures.

If it runs great, you might not want to mess with it. I had the common issues with mine, poor starting, random high idle at stops, and dying at stops. Besides, I tinker with any bike I own. So I did some mods, like removing the cats and the IAC, and sent the ECU back to SCS to get it unlocked, and bought their OBD2 interface box. That way I can change anything I want in the ECU, using the free software from SCS, called SXTune. The factory supplied dealers with software called SXCar, as well as new maps they developed. You used to have to go to the dealer to get new maps installed. Norton refused to release the software and maps to individual owners. You can now get copies of all that from folks here on the forum, but it still doesn't let you get in and make changes to the fueling and ignition maps. All you can do is load ad existing map. For the rest, you have to have the ECU unlocked.

There's a lot of discussion of the various maps in threads here on the forum, but I don't have any links handy at the moment. Some searching will probably find the earlier discussions about updating maps for aftermarket exhausts and such, as well as some more info on unlocking the ECU.

The above mostly only applies if you have the SCS ECU. I don't recall which model year you have, so it could have either the SCS ECU (a modification of their Typhoon design), or it could be the OMEX brand ECU. I have no experience with the Omex ECUs that were used on many of the 961s. I know they use a different mapping software and different adapter cables to make changes, but I don't know how readily available those are now. I do know that some of the Omex maps are available. If you have the Omex, you might PM Richard7 here on the forum, and see if he can give you an update on what you can do with them now. He and his dad have at least some experience with them, being ex-dealers for Norton.

If you want to mess with fueling mods, another alternative is a Power Commander. There are some threads about that here on the forum, so if that interests you, you might do some searches. As I recall, the one for the BMW 650 twin works with the Norton. It's no longer available new, but a year or so ago I saw them occasionally on eBay.

Sorry for the rambling answer. I threw in more info in case other folks might have similar questions.

Ken

TonyA said:

Hi Ken , Very interesting . A while back you mentioned wanting to get a bit better fuel mileage . Did you manage to do it ?

Click to expand...

Hi Tony,

the answer is pretty much no. I'm still averaging around 40 mpg.

Ken

I imagine that you have swapped the injectors, right to left and left to right? Or, they’ve been “cc’d?”

xbacksideslider said:

I imagine that you have swapped the injectors, right to left and left to right? Or, they’ve been “cc’d?”

Click to expand...

Not yet, but I plan to. From the data so far, I'm pretty sure that the side-to-side differences are caused by differences in the injectors. But I'll do the swap anyhow, just to be sure.

Ken

I switched back to the original injectors and swapped the left to right today, then took a test ride to get some data. I've just looked at the data, and as expected, the AFR difference also switched polarity, i.e. the right cylinder is now generally leaner than the left cylinder. Pretty clear now that the differences in AFR are due to differences in the performance between the two injectors. I'm putting the new Bosch injectors in the spares box. I'd probably have kept them in and saved the originals for spares, but then I would have to go through the mapping exercise again.

I've been generally shooting for an AFR of 13.2 for most of the base fuel map, with it a bit richer at full throttle and higher rpm. I'm not quite there yet, but getting closer with every change. The difference between the two cyinders' AFRs is in a range from .1 to .7. The engine runs fine over a fairly broad AFR range, allowing one to run on the rich side for performance and the lean side for mileage. In actual use, the difference is not very noticeable until it gets significantly larger than what I'm seeing. The bike runs great as it is, and I think a couple more tweaks should finish this exercise. Next project will be to put the D400 ECU back and finish sorting it out.

Ken

Hello Ken , When you get back to running the Delta 400 , will you be posting in the Delta 400 users group thread ?

Sure thing, Tony. Looking forward to working with the newer ECU again.

Ken

I was watching a UK consumer program the other day where an ebay 'dealer' was raided for fake automotive parts. They highlighted ngk plugs which caused misfiring and tested an injector next to an original. The spray pattern was a mess and the flow rate way off........

I am not sure that my approach is the wisest however, I intend to leave all of my potentially dodgy (non-Bosch) components until they fail, or not. Noting that the Coil and Head Temp Sensor have already failed and have been replaced. The bike is roaring like a lion, albeit an older, slightly sleepy lion with a soar tooth, but you know what I mean!

I realise the potential folly of this approach but I generally use the bike for blasting around the local hinterland only, chasing my mates like I was back in my twenties and as such I am rarely far from home. It’s a Cafe Racer after all! As a long time RACQ member I am only a phone call away from a lift home with other bikes waiting to be ridden, whereupon I can fix the Norton at my leisure. The only part of that scenario that is unbearable is the tirade of pisstaking that I (and the Norton) receives when this occurs! See enclosed.

This approach is not related to money but rather an ‘if it ain’t broke’ mentality. I realise that this will not sit well with you professional ‘fettlers‘ however, 9000 km is not huge mileage but I would hope sufficient to tease out the poorest of the knock offs. Also I find the subject a little confusing, noting that I’m not sure whether I have seen a definitive (consolidated) list of these items, their correct Bosch part numbers and an indication of where they reside (and difficulty in exchange). I realise that is up to me to get off my ass and research this which is where a bit of laziness comes in. I find it diifcult to motivate myself to search out faults that are yet to, and may never, occur!

You have my permission to berate me at will for this approach, or maybe agree with me if you are doing the same! ?

Stephen,

I'm sure your approach to bike ownership (and maintenance and fettling and whatever) is right for you, and a lot of other owners, including many of my friends. I have no reason to criticize it. But it doesn't work for me. If there's a gearhead gene, I must have got a double helping of it. I have friends who, like me, work on anything mechanical they might own, but particularly bikes. We repair and modify the bikes we own, and now and then build our own, and race them here and there, as well as riding them regularly in interesting places. But I also have riding friends who don't know a wrench from a hammer, but still love to ride. They buy new bikes and take them to the dealer for all their service, and when the bikes get fussy, they buy new ones and start over. I should also point out that they mostly are much more fashionably attired in riding gear than the rest of us. And there are a lot of riders somewhere in between those extremes. The common thread here is that we all love bikes and biking. So we all get along.

I've had plenty of folks who couldn't understand why I would want to change something on a bike that wasn't really broke (the engineers must have known what they were doing, right?) Fortunately, I don't get a lot of that here on the forum. A little now and then, but most folks here are very understanding of those of us with the disease.

Ken

Hi Ken,

As diseases go, that’s an awesome one to have, especially in your retirement! I have more of a slight itch than a full blown disease and like to fettle around the edges where I feel comfortable. Basic maintenance is no problem, pulling out the engine and stripping it to its last nut and bolt is I suspect beyond my knowledge and enthusiam level. That said, I am going to service my 990 Adventure next month, partly because I will enjoy it but mainly because I object to paying $100+ per hour for a mechanic to work on a 11 year old bike. Even going to do the valves - check me out! Did the DRZ 400 last month. Will work on the Norton too in future, when she’s a little further out of warranty. I’ll deal with the Bosch clones however, if and when they fail.

I’m with you Ken, get as down and dirty as like with your passions. Ride and enjoy.

Long live Norton.

Steve