My first 2.4 , need advice

**LOSTINJ** · 05-10-2019, 09:28 PM

Hard core 3.0 litre guy here , picked up a 200 , 2.4 litre and need some direction . cowling says 200 however has sticker that reads " powerhead assy 175 " . Here is what I know so far peeked inside with camera and looks like new , has WH 46 carbs with staggered jetting as follows . cyl 1- 82 cyl 2 -80 cyl 3 -80 cyl 4- 80 cyl 5-80 cyl 6-82 Does this sound correct ?

I want to ad stacks , tuner , and cut heads . how much do I remove from heads and who here can do it . All advice would be appreciated

Larry

**Motv18** · 05-10-2019, 10:47 PM

Been a while on the carbs but looks like individual jetting or available parts

compression test first it may be cut already.

Finding what it should be and what it currently is, always fun.

**Merc 2.5** · 05-11-2019, 06:34 AM

The 46 jetting sound rite for stock , like motv said need do compression test ,but on the 2.fo 32cc should b magical # for heads , it's already got one if the best tuna u can buy, stock up on jets for testing

**LOSTINJ** · 05-11-2019, 08:12 AM

Thx also not sure I follow last part of reply . I have the 46 carbs are the they the best for making power ? And also ballpark jets with heads cut to 32 cc and with that squeeze I assume I can run 93 octane ? r making power ?

**Merc 2.5** · 05-11-2019, 11:13 AM

Once air box is removed and heads cut gonna have to go up on jets prob.004-.006 range , so 80s and 82 in 2 &5 , I would start 84 and 86 In 2&5 prob , yes 93 only. 46 make good power , I run em on a 2.5 , remove liner from can , keep tuna, get set Carson reeds and stuffers , small wheel and let it spin up least 6500. dont lug it , this is a gud starting point anyway

**Merc 2.5** · 05-11-2019, 11:17 AM

O btw , if u only got 1 82 and it's in #6 simone messed with jets , also if 82 jet is on port side bottom its feedin #5. They cross feed for ex. Lookin at front ov top carb port side feeds 1 and star 2 , left side carb feeds rite side motor and Visa versa

**LOSTINJ** · 05-11-2019, 06:45 PM

thanks guys !! Here is what I know , the motor is very low hour after peeking inside and today did comp test and 100 even across the board . What is max comp I want 130 ? Also engine has 2 stage carson reeds . who cuts 2.4 heads that is good and dont say STR as hes a hack and fkkked me out of 10 k . Also DONT install bobs tuner ?

Thanks Larry

**Merc 2.5** · 05-12-2019, 06:27 AM

Tuna b waste $$ imo , ok so dont shoot messenger on this but, u should check comp with another guage , would really like to c 115 or 120 lbs b4 u start cutting heads ,, at 100lbs the 32 cc wont get u where it should ,, usually when they get to 100, I'm usually lookin to rering,,the added compression will likely finish the rings off in a hurry if that is ur true compression,, low hr should have close to 120

**LOSTINJ** · 05-12-2019, 07:40 AM

Ok But would a 175 hp have 100 lb comp ? If so its fine as the sticker on side of powerhead says 175

**rock** · 05-12-2019, 08:16 AM

What year is the motor. Made the 175 in several different configurations from 2.0 to 2.5. Also 100# compression is either an iffy gauge or maybe someone put the wrong heads on the motor.

Rock

**Merc 2.5** · 05-12-2019, 09:08 AM

Let's start by runnin serial? Behind throttle/ timin arm,or Welch plug. idk if the 175 had relief notch in cyl. I dnt think so but not pos, the relief motors only ones came with low #s. Could have wrong heads but from pic they match pretty gud

**LOSTINJ** · 05-12-2019, 10:33 AM

I picked up a omc 1985 235 last year for cross flow to sell , powerhead just rebuilt and had 85 across board and at first I said WTF and made a call to my Evinrude dealer friend and he said look at head gasket are they thick as nickel which they were he said to run on low octane . Point is what makes a 175 vs 200 vs 225 ? diff heads ? Diff carbs ? Timing ? Port timing ?

**rock** · 05-12-2019, 12:20 PM

All of the above.

Rock

**Merc 2.5** · 05-12-2019, 03:34 PM

I agree wit rock , but ur also comparing oranges to apples , rudes had quite few low compression motors , merc didnt go that route except on comp relief motors

**Motv18** · 05-12-2019, 03:43 PM

Guess you got the buyer beware

anyway if your taking the heads off it’s not that much more to rering and get it all up to ship shape.

With the part sticker on the on the block I doubt it isn’t a 175, but finding how much has been done since the original purchase could have it modded to 200.