View Full Version : Tuning PS205 for 4000' and why not an HEI?

09-14-2010, 10:40 PM
Hi all,

I just bought a new (to me anyway) '92 PS205. It's great and this is my 2nd PS205, I had a '94 about 5 years ago.

My previous '94 never gave me any problems, it always seemed to run like a top. However the boat I just purchased is really rough running. The engine seems OK pulling good vacuum, no water in the oil, etc. However I have absolutely no hole shot, the motor will not accelerate hard, although it starts and idles OK. When I go to WOT it just bogs out.

I'm at 4000' and the exhaust smells very rich, so I figure I have some tuning to do.

I just read a thread on carbs:
and it looks like I do have a 4160, at least it only has the single fuel inlet, with a built in fuel rail between the front and rear bowls. So I will be rebuilding that, with possibly some main jetting modifications.

Does anyone have a M.C. boat at roughly 4000' and a 4160 that could give me some jetting notes? Any other tips on 4000' tuning?

Also I read the thread on upgrading to electronid ignition at http://www.tmcowners.com/teamtalk/sh...ronic+ignition

That thread recommends using the stock coil. I'm wondering why not upgrade to a full HEI distributor such as those at http://www.jegs.com/i/Proform/778/66983BK/10002/-1 ?
Other than it's not a marine (in fact I'd like to find a marine HEI if you all know of one)

Lastly, how can I tell if I have an HO engine, other than by the carb? In the carb thread noted above is stated that the HO motor came with a 4010 and the std 351 came with a 4160 (single fuel live vs double) However my HID is MBCUxxxxxxx which I understand from the hull ID FAQ is a 351 H.O. 1:1. So I am assuming the previous owner put in a 4160 carb, but I'd really like to know for sure, instead of just assuming, any thoughts or ideas would be appreciated.

Thanks all!

09-15-2010, 10:46 AM
There was a thread on here about marks on the heads that identify HO 351's. I never bothered to look because mine is an HO. Never messed with HEI ignition on my Mastercraft or considered it because I have the electronic conversion. I have one in my 454 on my airboat, which runs good with it. My son's 454 on his boat has HEI ignition also. They are mostly trouble free but so is my conversion on my 351. My experience is that major changes usually bring inherent problems which must also be solved to improve the improvement. Short for if it ain't broke--don't fix it. .

09-16-2010, 10:57 PM
Well I got a nice surprize today, this was the first time I had the opperunity to look at the motor since reading these threads and getting some knowledge. So after looking at my motor I realized the following:
1) It looks like I do have an HO engine (YAY), and that the carb is a 4160, yay again.
2) I opened up my distributor, expecting to have to replace points, and to my surprise, it has the electronic ignition conversion, already installed yay again.
3) It looks like the boat has been in storage for a while, someone had marked on the oil filter, 03-01-2007, which I am assuming is the last time the oil was changed. I immediately went out and got a complete oil change kit (which I was going to do anyway.).

So due to the motor probably not having been run for a few years, I am assuming that my poor running issues are due to a fouled carb. So I'm ordering a rebuild kit from Holley tonight, as well as changing the fuel filter, and stuffing as much high octane gas in it that I can, in case the fuel is somewhat old. The tank was full when I bought it.

Of course change the spark plugs, and check the wires, and possibly replace them too.

I could still use anyones help on high alttitude jetting of the 4160, if anyone has any jetting knowledge, please let me know, THANKS!

09-17-2010, 09:39 PM
Change out your raw water impeller if you haven't already. Order two. The consensus around here is that it should be done annually. Cheaper then an engine anyday.