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Tossing around the idea of doing some work on my runaround motor, 86 mariner 150, front half converted to horizontal reeds, shaved heads, what’s everyone’s opinion on opening up the exhaust chest some? Lots of meat to work with in there, any suggestions?
Want to keep it as reliable as possible since it’s ran a lot, not looking for every last ounce of power.
Get a 2.5 :D
I have a 2.0 In the shop that I had done little grinding in chest , its a spare motor ,so I dnt no what its gonna run like , same as urs tho ,stock porting , 200 front half, 200 carbs, tuner etc , im curious as to how it runs now.
I wouldn't hog it out , be afraid of loosing little bottom end they do have
Not so worried about loosing a little bottom end more worried about opening it up and having the port timing limit the rpms it spins, does anyone know what kind of rpms these 2liters will spin with stock porting?Quote:
Originally Posted by Merc 2.5
U can run short prop and spin it to the moon but its prob gonna quit makin power under 7k I believe, use search function I have read a few good 2.0 threads
How much time would You like to invest and How much reliability from the power relocation to the right side of the graph is willing to be sacrificed?
Those engines were awesome for back in the day and served there purpose well.
MrZip hit the nail on the Head.
Attachment 480873
I had a 2L I was working on. Plan was a 200 plate and tuner, XR2 carbs, Carson reeds. Search champ motor porting specs for the ultimate 2L porting combo. Decide from there what you want and imo at least the loss of bottom end is either tolerated or solved with a prop change when you want to pull skiers etc. 200hp is doable with these. I’m sure others have done more but that was what I dug up.
even a stock 150 with the 200 plate and tuner and carb swap is around 165 or so on stock porting iirc. Great motors mine was a lot of fun
Curious what the horizontal front would get you on one of these... I've got an XR2 now with stock vertical reeds and WH40s that replaced a blown 2.4 200. Was thinking about harvesting the horiz front off of it and running it on the xr2... Might tear it down next winter and do the swap.
A 1976 175 with the big open chest, horizontal conversion, 200 carbs on a land and sea short tuner plate would run out of port at 7200 with a 28 on a Viper with 1.87 gears. Unless you have a really light and free running boat I wouldn't mess with it much.
What was your speed with that setup??Quote:
Originally Posted by Capt.Insane-o
We saw 79-81 in our Sprint races with a 24p. Mid 80's with a heavy fuel load running a 26p at Enduro's.
We've seen 88 lite fuel running a bigger wheel.
Capt. would know. I'm sure he's had one of his Stream's north of 90 with a 2L
with stock fishing motor porting?Quote:
Originally Posted by Baker343
It would crack 90 in cooler weather. That was the end of the rope though. The heads could only be cut so much on those motors, not that it did much for top end after a certain point. It really liked 6800-7000, sounded fantastic there.
Sounds like what I'm after for my viper! Do you think the 200 carbs made a big difference? lose bottom end much? I have a set of WH28's (off the 85' 200), WH18's (off an 80' 200), and WH40's (XR2 carbs) What did you cut the heads to (cc)?Quote:
Originally Posted by Capt.Insane-o
2.4Viper, don't mean to jack your thread, sounds like we're after the same results...
Dunno on those early heads, you could cut .080 off them I think before they would lose the water jacket surface and leak. Motor made 165 psi. Now that I remember the carbs were the original WH 1-2-3 with .080 mains, never touched the idle jets. Merc reeds. It ran and ran and ran and as far as I know still runs. The front half swap was worth 2-250 up top.
Went to a 260 with a 125 shot after that, then to a BP that ate the bridges and then to the 2.0 f1 motors which was about the best set up.
I have a late model 2.0 fat block that needs boring if any of you are interested in that.
The later 2.0s chest is closed up a lot more but with stock porting your not going to see a measurable gain messing there without correcting other things first.