What parts are interchangeable 90 2.4 racing vs 89. 150 xr4

**MercRoy** · 09-09-2019, 07:00 PM

Hey all

i picked up a blown 1990 2.4 racing merc it’s missing most electronics flywheel wiring carbs, reeds and heads. So it’s basically just a rotating assembly.
was wondering if any of my 89 2.4 liter parts are interchangeable. I have mid section and lower unit for the 1990 2.4 so if some of my other parts will work on this engine I may put the money in to finish it off otherwise I am going to rebuild the rotating assembly and sell it

**Merc 2.5** · 09-09-2019, 07:13 PM

What r u wanting to change ? Mid and lower gudnfor either power head ...

**MercRoy** · 09-09-2019, 07:18 PM

I ultimately want to put the racing one back together if some of the other parts will swap
The other 2.4 was complete engine with a scored cylinder
i also have a complete 1990 2.5 with blown cylinder
FYI I bought them blown up

**Merc 2.5** · 09-10-2019, 06:44 AM

R u talking bout lectrics, carbs and such? Carbs wont b no gud for racin mota, if the xr4 has the water cooled 40 amp ,I wouldnt bother using that system.
If has 16 amp system that will swap

**MercRoy** · 09-10-2019, 07:23 AM

I do have a 16 amp charging system
what are your with using the steel flywheel?

**MercRoy** · 09-10-2019, 07:25 AM

Will the heads fit? Or will that drop compression too much

**Merc 2.5** · 09-10-2019, 07:41 AM

Heads will fit but not sure of the cc of ea motor , would need to cc them or bolt on and do comp test ,,
Any 9 or 16 flywheel will work , red or green I believe , they made a red 40 amp wheel to but they r alot bigger

**MercRoy** · 09-10-2019, 07:47 AM

If I bolt them on what compression should I shoot for pump gas or high octagon?

thanks for the help

**Merc 2.5** · 09-10-2019, 08:04 AM

Added compression =more fuel/rejet also , 93 pump gas 140 145 , I shot for 145 and got got 145-150 been fine on 93

**bullet123** · 09-10-2019, 08:13 AM

1990 racing 2.4? Bridgeport?

**MercRoy** · 09-10-2019, 08:24 AM

Yes 1990 2.4 Bridgeport
also looks like intake and reed setup will bolt on from the stock engine is that advisable or should I look for the a racing setup somewhere?

**bullet123** · 09-10-2019, 08:41 AM

What kind of damage to the block? Is the bridge broken?

**MercRoy** · 09-10-2019, 08:43 AM

Bridge is not broken but cylinder is scored pretty deep rod and piston are gone For That cylinder but sure looks like it may have broken a ring

**TEXAS20225** · 09-11-2019, 08:14 AM

do you know if its was carb or horn? horn was a 7 petal reed mota i never had a carb bridgeport but lots of horn stuff all were 16 amp alum flywheel stuff

**TEXAS20225** · 09-11-2019, 08:18 AM

James Perry can put a steel sleeve in it, dont go for the fanged sleeve it junks the block because you have to cut the sleeve holder short to accommodate the flange and its not required for the right machine shop like perry