2001 2.5 running lean

[monzaspeed]

im desperate, i need some help. I have a 2001 200hp 2.5 Merc. with carbs and 6 months ago i melted 2 cylinders and bent 1 rod so we rebuilt the power head. 8 hours into the break in i noticed the temp going up so i turned of the motor, when we got home i performed a compression test & every cylinder was at 125psi accept 1 at 60psi. when we took the motor apart there was signs of running lean. every cylinder had scratches & #5 was melted. so we rebuild the power head once again, redone carbs, fuel pumps, pretty much everything that has to do with fuel...
but i noticed that the reeds where to open so i decided to replace with boysen reeds but they require to lower your idle air jets 2 sizes but the problem is that one of the jets is a 28 but mercury does not make anything smaller than a 28 & i need a 26. and then problem #2 now one of my local shops told me that in my year Mercury had some problem running lean in high Rpm so the suggested to go up 1 size on the fuel jets.

so pretty much i have a new power head but to scared to run it.
does anyone have any info???

[olmo40]

What size mains are you running ? Did this problem just happen or did you change something else ? How is your water pressure ? At what rpm did it get hot ?Do you know what the timing is set at?
Have you checked fuel flow / Primer ?

[monzaspeed]

both times i was running at 5000rpm, water pressure 12psi, i dont know where was the timming and water temp at 130. the jets on the carbs are oe. there has been no hi performance modification done to the motor until now that i replaced the reeds & still have not been cranked on... i hope this info helps u give me some suggestions.

[steelhead]

work the engine problems out first using the Merc reeds.

are you running premix or OEM oil pump?

after engine problems are solved then put in the Booysons and tune the carbs to those

[monzaspeed]

Thanks will do...