Converting efi to carb

[veitchracing]

I have a 1997 2.5 200 efi merc, I was wondering if it can be converted to carb like the older Mercs? If so what all do I need other then the front half?
Thanks
David

[FAST RALLY SPORT]

Why ? Is the EFI not working, EFI is quiker to start, most of the time better fuel mileage, and most times trouble free than carbs. Bobby

[veitchracing]

I know it doesn't make sence but yes efi isnt working leaned out one bank. I was going to put the carbs off a 225 on if it will work?
Thanks
David

[TEXAS20225]

u dont need front half just carb reed plate carbs, bleed hoses, change out the harness or modify yours a few small items like linkage throttle cam etc it s a snap for a experienced motor man i do it all the time both ways!!!!! get your injectors cleaned and a new ecu be sure to check your switch boxs they can cause one bank to lean out due to double firing leave it injected IMHO

[malexie]

Get a drag ECU and set it up like a ProStock DSRA motor. Then you will have something.
HP fuel pump and Reg will be needed also.

[veitchracing]

Who would you recommend sending the injectors to and can't they just flash my ECU?

[malexie]

http://www.brucatosvs.com/

[veitchracing]

That's who I was thinking aswell.

[Tony Brucato]

I know it doesn't make sence but yes efi isnt working leaned out one bank. I was going to put the carbs off a 225 on if it will work?
Thanks
David

Well, the ECU fires injectors in 3 pairs. Each pair fires an injector from each bank, so it's probably not the ECU.
It could be the injectors and would be worth checking, but it would be quite a coincidence to have 3 on one bank only and the other bank good.
The switch boxes are bank specific and could be the culprit, as could the stator.
I would index the flywheel at each cylinder and check timing on every individual cylinder. I wouldn't be suprised to find a problem there.

[TEXAS20225]

the stock ecu has its limits

[wrechin2]

I would index the flywheel at each cylinder and check timing on every individual cylinder. I wouldn't be suprised to find a problem there.

Couldn't tell you how many I have tested and found that was the cause of a powerhead failure from double firing on a cylinder from a bad switchbox. That is why every engine I build gets 2 new switchboxes. It is fairly easy to test them with a dial indicator. Just my .02

[veitchracing]

Thanks for all the info from everyone, it's been a big help. I also have another powerhead with 1 bad hole and by the sounds of it the swith box is bad correct?

[Tony Brucato]

Thanks for all the info from everyone, it's been a big help. I also have another powerhead with 1 bad hole and by the sounds of it the swith box is bad correct?

I wouldn't jump to that conclusion. There are so many different ways to hurt a cylinder, and I'm finding more all the time.:eek:
Check spark, check fuel, check cooling. The clues are there.

[wrechin2]

Not always a switchbox. I have seen so many of them bad that I address everything that could cause a failure such as switchboxes, poppet, carbs or injectors, thermostats and waterpump because I offer a 1 year warranty. Even though I can test the switchboxes for a failure, I can not determine when a switchbox will fail. Post a pic and most on here can help identify the type of failure. The easiest thing is to look at the piston. You can identify a lean condion versus a cooling issue. A cooling issue will have the sides damaged and the top black as the ace of spades (most of the time). A leak condion or detonation will have the sharp corners of the piston rounded and melted off usually at the exhaust port portion of it and will be grey in color. Just my experiences.

[veitchracing]

Here is a pic of the piston in the motor with one bad hole.

Thanks for all the help everyone!
David

[2stroking]

Here is a pic of the piston in the motor with one bad hole.

Thanks for all the help everyone!
David

looks like it may have been a locator pin coming out of the piston, although its hard to see for sure on my screen.. 2.5 fishing motors are VERY well known for the stock factory pistons having the locator pin come out and destroy the cylinder, heck ive even seen the locator pin go into another cylinder on the same bank and hurt a 2nd cylinder too!

i will not build a 2.5 motor such as yours without installing 6 new vertex style pro marine pistons in it-- its just not worth the risk of using the junk factory pistons and losing good boating weather, let alone the cost of popping another cylinder!

[TEXAS20225]

save your self some money on the injector cleaning send them to Power performance Engineering in FL 727 5739288 he is Brendan Powers does a super job on injectors 85.00 includes return shipping he has done great work for me for several years with out 1 single problem

[Tony Brucato]

looks like it may have been a locator pin coming out of the piston, although its hard to see for sure on my screen..

That's what I'm thinking too.

[Tony Brucato]

save your self some money on the injector cleaning send them to Power performance Engineering in FL 727 5739288 he is Brendan Powers does a super job on injectors 85.00 includes return shipping he has done great work for me for several years with out 1 single problem

I'm glad that you're satisfied with Brendan.
We also do a super job on injectors here. Our price reflects the extra time we take to achieve the most precise results. http://brucatosvs.com/fuel_injector.html
When you're trying to diagnose an engine failure, our meticulous analysis of each injector offers information that normal injector cleaning service might miss.
In that regard alone, the extra $11 per injector is money well spent.