1987 Looper v4 140 RPM only 4000

[THEFERMANATOR]

I have mine set so it idles at around 1300 on the hose, and idles at 600-650 in gear. You want to keep the idle speed down some if you can, the V4 gear case clunks pretty loud on shifting if the idle is up there. Your current idle speed on the hose though can fluctuate alot. My engine with the 85 carbs idled up around 2200 on the hose, but dropped back to 750 in the water. You have to have it in the water at the correct ride height to properly set idle speed.

[nymack66]

Thanks a million guys , Boat ran like it should , Low and behold it was the damm lower unit it was a v6 all along , New v4 lower unit runs like a rabbit , No stalls etc , I am running a new Aluminum prop 13 x 19 , I am only hitting 4,900 RPM at WOT , (increase by 1000 from V6 unit) While I am very please I may downsize to a SS prop I have 13 3/4 x 17 this hopefully push me over the 5k RPM at WOT ,
However an important issue pop up , I install a new Temp sender and gauge for the first time (no previous benchmarks) I notice at WOT the temp jumps to 180 degrees and pulling back to under 4 k rpm instantly drops it to 140 degrees. New T-Stats and water pump , Strong water discharge (not as strong as the v6 ) just my observation. I am wondering if it might be the impeller since I use the one from inventory , I am not sure how old it is but a visual on it looks good.
Note I have double sender on this block this is starboard side , I will connect the port side and observe the readings on it tomorrow.
Bottom line is I am very happy with the progress on this engine at this point. I am almost there I can smell it.
If any one on this site needs that V6 lower unit I will trade it for a V4 or something just let me know. I have a new spare cdi engine harness also.

[THEFERMANATOR]

Sounds like you need a 15 or 16 pitch prop to get you up to 5800. 5500 WOT is minumum if you want decent economy and acceleration out of it. As for your temp issue, sounds like you need to check the water diverter valve on the throttle linkage. Somebody may have installed the valve 180 out and it's letting it run cool at idle, and hot when loaded. The temp should be running around 120-140 at high RPM's, and 160-170 at idle-3000. It isn't meant to be able to go in 180 out, but it is possible. If this happened, it would do EXACTLY what you describe. And your hot horn should have been blowing your eardrums out at 180 engine temp. It should go off at 175.

[THEFERMANATOR]

Go to this post here and scroll down, you'll see where SKOOLS posted pictures of the valve. Make sure that the the piece sticking out off of the valve closes off the forward port when it is in the idle position. If it goes in the other way, it will block the water flow to the T-stats at idle causing low temps at idle and then let water go them at higher RPM's and causing overheating. These engines need higher temps at idle to make them burn cleaner, but lower temps under load due to cylinder temps being so high in them.

http://www.wellcraftv20.com/communit...ead.php?t=7580

[nymack66]

I swap my prop at Boaters World for a 13 x 15; I will post the results when I test it in regards to speed and RPM at WOT.
I check the diverter valve it was installed correctly.
I think I found the high temp issue both Diaphragms on the thermostat installed backwards! And the little hole on it plugged with gasket sealer!! This installation will prevent water from flowing thru the heads!
I followed the diagrams from the OMC manual when I install this some months ago, it wrongfully shows the diaphragms backwards so I install it that way, despite my reservations at the time since the engine had none installed.
Today I check the OMC Service manual low and behold it clearly shows the correct orientation for the darn thing.
This is clearly why Jessie Ventura says you can’t write legislation for ignorance, I clearly could have been arrested and charged :) I blame the parts manual.
I also installed the second Temp gauge toady and connect up. No time for testing on the lake. Did a dry run on the muffs checking for leaks, looks good.
Thanks for all your help and attention.

[nymack66]

Boat runs like a like a champ, RPM is up to 5700 at WOT with a 13 3/4 x 15 Aluminum prop . I did not clock the speed , damm GPS was in the car !
Temp is 140 at WOT and drops to 120 at or around 2000 RPM.
Now just for the hell of it, I rescued a V20 that was slanted for the dumpster today, I brought it for the Hull only its in great condition I could not pass it up. I will have it re-panted since the previous owner painted it with a roller brush and then looks like he was rained on !! I will post pictures. Check out the craiglist listing for it . http://orlando.craigslist.org/boa/645211943.html

[Stinky_Hooker]

Ferm....you are my hero.

[THEFERMANATOR]

Originally Posted by Stinky_Hooker

Ferm....you are my hero.

But will you respect me in the morning?

[Stinky_Hooker]

I doubt it. You are merely a piece of meat to me.



Get use to it.

[msbhammer]

Nice V Pics. Also dig teh webpage.