A ? about tighter heads

[xb03]

Ok guys, I have a few questions about cutting my heads, this is what I have "stock 1998 225pm SS no oil injection or black boxes". I aready run non-ethonal 93 and timing set at 23deg.
#1Would cutting my heads make my 350 hour motor less reliable?? I know in a way anything performance wise is less reliable but.......
#2What cc to cut them to 33??
#3Will I be able to pull a tube anymore with the increase head temp?? In the summer it runs 155deg pulling a tube??
Thanks, guys!!!!

 

[2003225X]

I know we all want to have more power and go faster but I would be satisfied with a 225 pm running the numbers you said it does on your boat.

I had thought before abpit getting mine done but I am not messing with it. The motor runs too well to do something to it and have a bunch of problems.

 

[silverbullet02]

Where's your compression at now? I'm at about 34cc and 140-145 compression. I ski with mine and never had a problem.

 

[xb03]

Yeah Matt, motor does run strong as is!


I haven't checked the compression with a good gauge yet, because they were all around 112 with an old gauge lol.

 

[D.Ally]

You saying u have 350 hrs on it right now .?....if so i would think rebuild befoure doing anything else !

 

[xb03]

You saying u have 350 hrs on it right now .?....if so i would think rebuild befoure doing anything else !

Yes, around 300-350 hours.

 

[fnshrmaster]

You saying u have 350 hrs on it right now .?....if so i would think rebuild befoure doing anything else !

Why would you rebuild a steel motor at 350 hrs? There are guys running them upwards of 1000 hrs without a hitch. I think Whipper has 1000 hrs on his.

 

[Bobalouie]

You say you have the black boxes removed, which, I assume you are talking about the timing advance modules, set your timing at 25 deg and it will be snappier off the line and have better throttle response, and it is free.

 

[allimax]

Jared, I was thinking the same thing, 350 hrs should be nothing & why is she set at 23 deg if you run good fuel? Time for that leakdown tester so you know for sure what shape she's in. But the way she runs............... What a minuite:confused..............it was that 1/8th mile runn'en video you were in:rolling eyes..................hell, that motor's toast................you need that 280 before the rally...............tell the wife we all said so!!!:big grin

 

[John S]

You saying u have 350 hrs on it right now .?....if so i would think rebuild befoure doing anything else !

Dave, not errybody's promax has a TJ port job, 180# of squeeze, and spins 9500, lol.

 

[xb03]

Dave, not errybody's promax has a TJ port job, 180# of squeeze, and spins 9500, lol.

My promax was babied before I got my hands on it lol!

 

[John S]

My promax was babied before I got my hands on it lol!

If D Ally's promax was a baby, it would've been taken by child protective services long ago. Cause that baby's done been whooped on frequently for being so bad, lol!

 

[JASONPIJANOWSKI]

Hey john my boats faster than yours!!!!!

 

[whipper]

You say you have the black boxes removed, which, I assume you are talking about the timing advance modules, set your timing at 25 deg and it will be snappier off the line and have better throttle response, and it is free.

As Bobalouie said, Premix 25 deg not 23 espestially with the timming advance box not there. 33cc head put on around the 300+ hrs on my 96 also. If your closer to sea level than me at 2200ish ft, try 34cc. More snap out of the hole. No differant top end. 8 years since rebuild on mine. Hours ?{lots!!!} Running strong still but the years thing has me thinking about things now:] Does warm up though skiing. Never any problem just running though. Mine never liked 20-30mph though even before the heads.:beer:

 

[xb03]

James, what was your temp before and after cut heads while pulling a skiier??

 

[JOEALLY]

Jarrod, you need to just bring me that wore out old pro max and get you a fresh 260/280 :big grin:big grin

 

[xb03]

James, what was your temp before and after cut heads while pulling a skiier??

Joe, the thought crossed my mind last night about swapping for a 260 :big grin

Will 2deg of timing really be noticable??

 

[D.Ally]

Thanks Johnnnyy theres been a little widdlin on the inside :twisted evil :beer:


Sorry XB 03 seemed like alot of hrs , i have never had a motor togther for that many hrs .. i spin them so i guess i like to see them apart every three yrs ,

Dave

 

[D.Ally]

Jason , semmer down u havnt even drivin it yet !!lol

 

[xb03]

Thanks Johnnnyy theres been a little widdlin on the inside :twisted evil :beer:


Sorry XB 03 seemed like alot of hrs , i have never had a motor togther for that many hrs .. i spin them so i guess i like to see them apart every three yrs ,

Dave

Its all good, I do want to re-ring it with new pistons. I did a compression check today with a good gauge, all between 136-139