can i change power pac,s

[dannyman3]

i have 1990 200gt was looking to upgrade the power pac, to 225 or 250 from what ive read so far the timming is all thats diffrent also can i jet the carb,s on the hi speed side only and if so how far

 

[kenmyfam]

Re: can i change power pac,s

i have 1990 200gt was looking to upgrade the power pac, to 225 or 250 from what ive read so far the timming is all thats diffrent also can i jet the carb,s on the hi speed side only and if so how far

Just a quick question.....Why ????

 

[CharlieB]

Re: can i change power pac,s

Before trying that I would take a long hard look at the part manuals for BOTH engines.

Compare block #'s, piston #'s and carb #'s to be sure that port timing is the same, carb CFM, etc.

I'd almost bet money that you are going to find differences beside the ignition packs.

 

[daselbee]

Re: can i change power pac,s

I agree. ^^^^^^
The CDI powerpack for the 200 and 225 is the SAME. This tells me that there is no difference in PPs or ignition timing related powerpack issues.
The carb #s are the same for both the 200 and 225.
It will probably be in port timing.

 

[dannyman3]

Re: can i change power pac,s

Just a quick question.....Why ????

yeah i know a lot of you boaters dont understand but ive been a drag racer for the past 30 years and love tweaking on motors im new to boating i traded my racecar for this boat i just want to tweak the motor out im allready changing the heads to the smaller chambers to up the compression and want to up the spark and add bigger jets thats just what ive allways done with cars and it spilling over to this boat stuff what i seen the powerhead is the same all these looper motors 200-250 other than the carbs and timming

 

[dannyman3]

Re: can i change power pac,s

Just a quick question.....Why ????

plus im tring to keep up with the 150 merc,s

 

[daselbee]

Re: can i change power pac,s

Well, go back and look at the parts books.
You keep referring to 250hp, but in your year range...say 1989 to 1992, the 250s were V8s.
The 90* loopers were changed to a fingerported design in 1993, and the HP was upped by larger carbs. I have a 1996 200 and a 1998 225 and the only difference is in the carbs. The bores are much larger on the 225.
You will not find any ignition timing difference. Port timing maybe, but not ignition timing.