Im going to post up another 500 injector comparison thread soon when I have time to load videos and pictures based off some testing data I volunteered to do for a guy from Rochester NY, he was told by a big name, well known injector company that their Lucas 42 lb was "so close" to the merc it would make no difference, I offered to flow and document them for free against 4 good, average, oem 500 injectors. Well, they were 13% high on a static test , if his old AFR was say 12.0 at wot, it would now be in mid 10s, but where real story was was in mid range test that are very similar to running the boat, at 5000 rpms, 12 milliseconds PW they flowed 50+% high and similar at other settings as they have a very robust curve and flow considerably more partially open. I was so curios to see how they did, I did this test for free and Im paying the shipping back. I will extend the same offer to you, since I have 4 good average 500 injectors sorted out, I will at no charge flow 4 of your new ones simultaneously at same time I flow 4 stock ones on my 10,000$ ASNU machine, share the data, pictures, videos, a flow data sheet withe every test ran, then I will pay the sh and insurance back to you if you'd like, im curios myself, Smitty

These ones?
Says 1 year warranty.
Carboncow I'd take Artic up on the offer.
Then return if no hassle if they aren't up to snuff.

the thing the op mentioned of '1 year warranty", sure, that's fine if Ines defective BUT, what people do sometimes forget is that these mefi engines have no self tuning, they are blind speed density, no 02 feedback. If say a injector flows low, is too small, acts up, unless it dies completely , it often melts that piston its supplying. The one safety the engine has, a 1 wire knock sensor, pulls a little timing once it gies lean and starts melting the cyl from the possible knock, it doesnt "save" the motor from being too lean or rich. So say it dies lean it out at a certain rom, pw, etc, the leanest cyl goes poof, boating seasons over, engines coming g out, injectir warranty doesn't cover that. I run every set of injector I sell or install acrossed my.machine for good measure and I have found "bad" ones, smitty

Oh I get that.
I wasn't mentioning the warranty as to imply they're up to snuff or will perform or the warranty guarantees that.
They could have a 50 year warranty, meaningless in my eyes if they don't perform as stated for the application.
Just maybe he could use the "warranty" and return them if they under perform after you run them.

Thanks again guys. Still not getting updates.

Cheech...that is the link
1BigJim: it's individual injectors not TB

So ArticFriend: If I"m understanding you want to flow 4 of the new injectors to see if they stack up?

So the seller got back with me (Ron is the name) and appears to be out of Fairview Heights, Illinois. He said he had sold many of them for my spec w/o issue. I pulled the trigger on ordering them even knowing we all know it's prob to good to be true. If he claims money back guarantee it's better then anything else I've been able to figure out.

Event if the OEM was available the cost would be to much for me. I know you guys play at a higher level then me so I'll roll the dice.

so back to ARticFriend's offer which I think is great. I'm going to have these injectors on Thursday and be installing them up at the lake (Lake Erie) on Friday and I'll know pretty quick if they suck or not. If you want I can send them to you if they don't work if you are still interested in testing them. IF they do seem to work I'll prob keep them in till fall but would be happy to send them to you then if you are still interested in finding out if they are a worthy substitute and/or consistent between injectors. I'd assume you are only interested in testing if I claim they worked for me?

EDIT: Now that I've redigested the posts I'm guessing Arctic is claiming they may "seem" like they are working but flowing in a way to damage the piston. So no way to know unless I test and then pull the and send them off?

Again...thanks to all for helping. Truly appreciated.

I would take artic up on his generous offer BEFORE you install them on the engine and possibly cause damage.

Well the injectors came a day early and he has included his "matched set" chart with it...which I didn't expect because the local guy who said my OEM injectors were fine also didn't do that and I just had to take is word. I've attached the document for your review to tell me what the science all means and if it's BS...or not.

EDIT: numbers/info on injectors reads 0 280 1556(or 8) as well as along the top D 684 006. On the other side they state: 380cc/36#. Photos now attached.

EDIT #2: Ran the numbers at 3 bar. Avg 385.25cc with diff from avg. ranging from -.45% to +.85% with a total different between min. and max of 1.31%.

Thoughts on his data at different pressures and duty cycles?

Send them to Artic, as already said, before install. Let him prove them out.
Send your old ones also. From what I'm reading you aren't sure it is an injector anyhow.
Did the local guys test come back all of them good?
A day to him, he test one day, a day back to you.

IMO anyone could of laser marked the 380cc/36#.
But the molded in number side that does appear to be a Bosch symbol.

The local guy owns an auto and marine parts and machine shop with a good reputation...but he's a character. He supplied me with a bunch of theories about my V/P engine because there were no manufactore plates on the block. He had me going in one direction. We talked about some issues I had post new long block and he would test the injectors at the end of the season and I would grab them in the spring. Well spring came around and he could not find them. When he did find them he said they were "fine" but proved no data which I was not happy with for $150 because all the other guys online said any good injector guy would provide a sheet from the flow/pop tests. They were just all thrown in a oily bag like I gave him. No confidence. Then it was proven by another online guy with great info that this local guy had no idea what he was talking about with my engine option designation because we reverse engineered the engine from the outdrive collar.

So long story short...I don't trust the guy who tested them up on Lake Erie and my symptoms are all mentioned above and those symptoms fall in line with every other online guide I've read on what bad and leaky injectors act like. He did claim that his machine didn't have print outs. At 25+ years old it sure should like a good idea to get new ones...but who would have guessed I could have found injectors for the space shuttle quicker then for a run-of-the-mill Volvo Penta 7.4 Gi engine.

I'll prob get with Arctic on how quick we can do a turn around on both sets. I'm going to do an oil change tomorrow and make sure my current injectors are not dumping fuel into the oil and then I'll assess how long I can do without the OEM injectors too.

I see Arctic is in Frankenmuth and thus only 2 hours away from our place on the western basin of Lake Erie. I could always run them up or down to move things quickly.

Im sure they are close, at static they will most likely be within 98%, its the part throttle settings where they may flow low or high. I bought 33, 34, 36 38 and 40 lb injectors from varios suppliers at one point trying to find a "match " to the oe injectors and although the 36 lbs were almost identical to the oes at static (100% flow, fully energized) they had different characteristics, flow rates at various rpms and settings that didnt match the oes. At that time I did NOT test the exact injectors you just purchased. Panther Geronimo, a member on here, was fixing a hurt 500 efi, melted a piston in hottest cylinder and sent me the injectors, although the injectors had some stuff carefully ground off them, a search on remaining numbers matched 36 lb Bosch automotive injectors, when I flow tested them against some average oe 500 injectors, they flowed a little different and did not match . When FU marine tuned this oin water, it needed some more fuel added to the tune in some ares and if I remember right some pulled out.
so my offer to you is at no charge I will flow and test 4 of them simultaneously against oems and give you the real world answer, it would be greta if they match close enough to be a viable injector to use as a replacement. I will also pay the return sh, etc and do it expediently. I see your near lake erie, would be a jaunt but I would even be willing to do it while you wait if you drive up.