Carb vs EFI ?

[skialot2]

What are the pros and cons of EFI vs Carbs?

I picked up a 2001 Mercury 200 EFI. I already have a 2000 Mercury 200 Carb motor on my boat. I am thinking about putting the EFI on instead. Why is an EFI motor better than a carb motor?

[22R]

I am no expert, but I think EFI behaves better as far a starting and idling and Carb may be more reliable as far as a plugged injector not lubricating a cylinder. Carb thirstier too.

22R

[LakeFever]

I’ve run both. When kept in top shape both are fine. Efi starts easier and idles better and is more consistent. Carbs have no limiter which is nice if you’re winding it up. I’d definitely suggest cleaning and flowing the injectors and doing all the black box delete, oil injection delete stuff. These are old motors now and premix is reliable

[Jim Speros]

I've had both too. Both run great when cared for. As they get older a carb is less expensive and easier to maintain. Carbs are also easier to troubleshoot.

[OnPad]

Supposedly the carb version has ignition cut for a rev limit. The efi relies on fuel enrichment for a limiter. At least that's the way the service manual spells it out for cdm engines.

[tlwjkw]

Supposedly the carb version has ignition cut for a rev limit. The efi relies on fuel enrichment for a limiter. At least that's the way the service manual spells it out for cdm engines.

simple solution, change 'em ta switch box stuff................. get rid of all tha extra junk.

carbs less problems that come with age... easier ta diagnose problems.. usually cheaper ta maintain..
efi more convenient (user friendly) till it develops a problem..
performance limited (production efi) modified efi (hi performance ecu's and such not included)......... jmo.

[OnPad]

[QUOTE=tlwjkw;3432516]simple solution, change 'em ta switch box stuff................. get rid of all tha extra junk.

That's what I did to my cdm efi engine. Installed 16 amp electrics from a old blown up 2.4 carb engine. I didn't have a extra efi wiring harness, so that took a bit to source for a reasonable price. The newer tpi doesn't plug into the older harness, so it got repinned. Only thing I have left to do is mount coils.

[tlwjkw]

yeah.. we changed 'em on any motor we bought, traded, etc. for.. they are jus to limited.............

[skialot2]

Does the EFI give better low/midrange power or vice versa?

[skialot2]

I have been studying the service manual for these motors. For some reason the 200XRi has a higher factory RPM range (5000-5800) than the 200 carb (5000-5500).






As far as I can tell, according to the manual, the rev limiter is for carb models only. The manual breaks down how it works for carb models. But makes no mention of a rev limiter on XRi models. In the fuel injection section it says maximum RPM range is 5750-6250. I think that may just be the limits of the stock system. You would not want to try to limit RPM by restricting fuel. That would cause a lean condition and kill the motor.

[tlwjkw]

thats for tha CDM motors... its like tha DEMs.. want complete control of everything.... reason for goin' ta switch box 'lectrics....

bone stock tha efi has a little advantage with low ta mid power... but anything can be had with either thru tha set up... tuners, gears, props and such..... jmo.

[LakeFever]

The laser ecu richens the fuel up to limit the rpm. If you’re running a light boat or an easy to spin prop you can turn the motor well past 5800. So far mine will go 6200 maybe 6500 on my best run. 28 pitch or higher is all I’ve run so far. I have a buddy I’ve been running with who spins 7500 on his but it’s a single seat lightweight Ventura. My motor gets more than twice the fuel range at 3/4 throttle then it does when I’m wide open so the top end enrichment must be considerable.

[skialot2]

This motor is a 25" shaft. I figured if I run it on my boat with the jackplate all the way up it will run like my 20" shaft with the jackplate all the way down. I pulled the lower unit to put a water pump in it. I could not get it back on. The crankshaft seal carrier was in the way. So, I decided to change this motor to a 20 shaft. I have everything I need including the gaskets. This powerhead has already been off. 2 of the 4 long studs in the powerhead were extra long. When I took the powerhead off, there were 2 of those crankshaft spline seal carriers. One still in the end of the crankshaft. The other in the way of the shaft down in the adaptor plate. This is definitely a replacement powerhead. Looks like an F block with a production date of 09/27/05. You can tell the heads have never been off and the case has never been split. The Powdercoat is still sealed on the head bolts and case seam.

[Merc 2.5]

What are the pros and cons of EFI vs Carbs?

I picked up a 2001 Mercury 200 EFI. I already have a 2000 Mercury 200 Carb motor on my boat. I am thinking about putting the EFI on instead. Why is an EFI motor better than a carb motor?

Carbs definitely easier to diagnose, efi will start easier cold, a good set carbs that's jetted just right idle perfect and never miss a beat, starts real easy warm , can rejet carbs for power mods instead having ecu modified, more Reed noise with carbs and little dirtier under cowl. I lean my idle jets out (it will idle at higher rpm but I start n gear) and there's no bog and great throttle response then jet mains according, carbs prob little more thirsty but how thirsty depends on carbs you choose to run , if i was to run efi I would want hipo efi not laser /consumer efi just my .02

[LakeFever]

I do find the laser to be quite dull in response. This is my first efi outboard and all my previous were carbs. If I’m cruising 30 and hammer it the carbs blast off like a rocket. The laser rolls on much softer and smoother. I do love the clean engine compartment and the top end out of this laser has been great. Starting is easier but still a little tricky when cold because I deleted all the black box helpers. With just switch boxes it’s still prone to stalling when cold.