Carb To EFI

[marky12]

I'm new to forum so I hope i'm posting in right area. I have twin 1998 Merc V 175s carburated that I would like to convert to EFI. Does anyone have a detailed list of what I would need, and best place to find all the parts? Thanks in advance.

[CircleHook]

What is it you expect to gain? Your plan is to take extremely simple dependable motors and put used EFI systems on them? Those used EFI systems are available because they blew up the motors they were on. New EFI systems are going to literally cost thousands each. Sell me those and go buy 2 already properly running EFIs.

[billybob]

YEA the older analog ECM,s are getting old enough now, that they are starting to fail. Merc. wants $1,450. CDI wants $1,250. THE best bet is the brucato units, about $1,000. A dealer can go thru carbs. for about $500.

[CircleHook]

and welcome to S&F - there are some very knowledgable folks here (knowledgable is not me) and they are very willing to help- a little smart azz sometime but great peeps.

[marky12]

Thanks guys! The reason i wanted to go with EFI is because of starting issues. Motors start fine when they are cold (first start of day) and right after you shut them down (hot) they fire back up in a second, but the problem is after they are shut down for an hour or two they are hard as hell to start. Both motors act pretty much the same way. All carbs have been rebuilt, fresh plugs and it didn't change anything. It would be so nice just to turn a key anytime and fire right up! I heard 175 carb engines have hard start issues. Any suggestions would be greatly appreciated.

[tlwjkw]

sounds like ya startin tha motors jus like when cold but without hard bulbs and/or usin' enrichner?...... either go to small 'lectric fuel pumps or pump tha bulbs up tight again after setin' awhile.........

[marky12]

I have already installed the small electric pumps to come on when ingnition is on.

[BlazerVA]

I'm in the process of converting a 200 Blackmax thats carb to an EFI. I asked the same question you did but couldn't get any real info on how. I've got a Mariner 200 that the oil injection went bad in and popped the number 5 hole. I'm using all the components off of it for build. So far the linkage, reeds, intake, efi harness has been swapped over. Waiting on the injectors to get back from being cleaned and flowed. Gonna plug off the oil injection and keep it premix. Also changing the reeds to the CCM reeds and crankcase stuffers. It's not that bad if you have a good donor motor.

[tlwjkw]

I have already installed the small electric pumps to come on when ingnition is on.

did ya remove tha mech. pumps?

[marky12]

Yes I did. In reply to BlazerVA, let me know how that conversion works out for you. I think all I need is the complete throttle body with sensors, VST tank & pump & ECM. I have found most parts, but the ECM is the hardest part to find because it has to be from a 175 and they are harder to find than the 150s or 200s. Plus I have twins, so I’m trying to do this to two engines. I wish I could find a complete blown 175 EFI doner engine or two.

[R.Allen]

The ECM is the scary thing. If its got issues it can be expensive. Have you checked Craigslist? Sometimes you can find a blown motor for pretty cheap.

[marky12]

Your right about the ECM. At this point i may just start looking for a blown parts motor. I have been watching craigs list

[Umassot50]

If you really want to get into a project, look into microsquirt pro 3. You can use jenvey throttle bodies. Look them up.

[BlazerVA]

Had a issue last weekend with the old fuel pump not putting out enough pressure. Had to order a new one. Went ahead and replaced all the o-rings on the VST while at it. Havent ran it on the boat yet but started it up on the hose. Fired up on the first bump of the key. Gonna get it out this weekend hopefully and see how it runs on the boat. Have you gotten anywhere with the motors yet?

[marky12]

No, I’m keeping my eye out for a set of 150-200 EFIs or Optimax. I’ve missed out on a couple because if there a good price you need to jump on them right away. I’m kind of torn between the EFI and Optimax. EFIs are good motors, but outdated and getting hard to find certain parts. Optimax’s are more fuel efficient, but a little more complicated.