Fuel injector service/recalibration

[pcbayou]

(See the update below. The cleaning and recalibration worked, at least for now). Anyone familiar with having fuel injectors cleaned, serviced and recalibrated? A new mechanic says they could be the problem with my Suzuki DF115. It won't go above 3500-4000 rpm, yet again. I wasn't familiar with recalibration, but the price isn't much more than I've already paid for the latest repairs. He said no place in Panama City does such service, so he'll ship the injectors to a shop he uses in North Carolina. They'll be back in 1-1/2 to 2 weeks. False hope? Here's a link with more background info: http://www.bigbendfishing.net/phpBB3/vi ... =2&t=42587

[Salty Gator]

I’m picking my boat up today after having the injectors replaced( they sent mine off to be cleaned and put in a previously cleaned set. They get flow tested and illl get a report on how dirty they were. He said my vst filter was really dirty also, and cleaned that. My rpms have dropped also, I thought it was due to the tower I had installed, but the guys at power tech props think it’s related to the injectors. Plan on running it this weekend, I’ll report back

[pcbayou]

Thanks, Salty Gator. It sounds like your troubles are similar to mine. I'll be curious to hear how your boat runs.

[Juan]

I had the same symptoms with my old motor (Yamaha F150). The rpms wouldn;t go over about 3K. They sent the injectors off to be cleaned somewhere in Florida and as SG already said, I got a report back with them stating the percentage they were spraying before and after the cleaning. It ran like it should after the cleaning. I've since learned there's a place in Dothan that has the equipment to clean them (Dothan Outboard - 334-714-5189) and there are several online. If I had known that in advance, I could have saved some coin. If I remember correctly, the price runs about $25 for each injector.

[pcbayou]

I was quoted $25 each for cleaning, plus $30 each for recalibration if needed, plus labor to reinstall them. That's worth it if it works. I'll wonder, too, if that could have been the problem all along. That would really have saved a lot of coin.

[fishinfool]

Having dealt with injector problems over the years in the automotive industry, I have seen many that were dirty causing the spray pattern and flow rate to be adversely affected. That being said, I have never heard of them needing to be "recalibrated".
The way injectors work is the body of the injector is mostly comprised of an electromagnet that when energized, pulls a pintle (needle) from a hole, that allows pressurized fuel to flow through the unit. There are no adjustments available to the flow amount or mechanical properties of the injector.
Maybe they are referring to a software update or reflash of the engine control module???

It just seems to my oversimplified mechanic brain that a complete cleaning would be sufficient.

[pcbayou]

You got me to wondering, fishinfool. My friend Google took me to several sites on recalibrating injectors. As usual, opinions are plentiful and expertise is impossible to judge. It sounds like calibration involves timing and amount of fuel flow for each injector. You've given me good information, which my nonmechanical brain needs to ask questions. Thank you.

[pcbayou]

Update: I got the Suzuki back after the injector service, and it's running like new. They found one injector was flooding and two were running too lean. I'm still not sure I understand recalibration, but I'm good for now. We'll see how long it lasts. For anyone curious, the company is in Apex, N.C.: http://www.brucatofis.com/index.html

[fishinfool]

[Steve Stinson]

Do they sell injector cleaner for boats? I know I run a can through my Cummins diesel on occasion.

It seems to me that running some Sea Foam or injector cleaner through your outboard every now and then may help avoid this issue.

- Steve Stinson

[pcbayou]

My mechanic recommends Stabil Marine 360. I've used other additives before, but this problem seemed to call for more than cleaning. We'll see, I reckon.

[Salty Gator]

I haven’t gotten my flow report yet, but I did go from 4500 to 5000 rpms and top end from 33mph to 39 mph.

[pcbayou]

That sounds good, Salty Gator. I pushed my Suzuki up to 5,500 rpm/33 mph yesterday, which was plenty fast for me. I’m glad your motor is feeling friskier too.

[rockyg]

You need to be turning at least 5500 at full throttle on a modern 4 stroke. Close to 6000 is even better. This seems to be an almost universally accepted rule of thumb. Too much pitch loads the motor too much, like being in too high of gear all the time.

SG I have the Power-tech version of a Yamaha "Reliance Series" prop, three blade, 17 Pitch on my F150. At 5750 rpm I'm showing 44-45 on the GPS running a light fishing load. The boat was a couple mph faster without that heavy azz Minn Kota on the bow and the TM batteries.

The Pathfinder guys said they rig most of the 2200's with a 250 SHO Yamaha. Now that would be a rocketship.

[Salty Gator]

You need to be turning at least 5500 at full throttle on a modern 4 stroke. Close to 6000 is even better. This seems to be an almost universally accepted rule of thumb. Too much pitch loads the motor too much, like being in too high of gear all the time.

SG I have the Power-tech version of a Yamaha "Reliance Series" prop, three blade, 17 Pitch on my F150. At 5750 rpm I'm showing 44-45 on the GPS running a light fishing load. The boat was a couple mph faster without that heavy azz Minn Kota on the bow and the TM batteries.

The Pathfinder guys said they rig most of the 2200's with a 250 SHO Yamaha. Now that would be a rocketship.

Working with power tech now to get repropped