Phantom 25 1985 - Merc 450R

**engineermike** · 08-01-2021, 09:41 AM

Originally Posted by Toffen

… I suspect the oil changed its caracteritics after getting hot.

This is absolutely what is happening. The heat itself isn’t likely to damage anything unless it’s well over 200 deg F. The hottest I measured was 120 F when I was messing with it. The viscosity of Mobil1 0w30 drops from about 120 cst to 45 cst when heating up from 80 deg F to just 120 deg F. The oils I was entertaining, but never tried, were Mobil1 0w50 and Shell Morlina S4 B 100. Both hold their viscosity better at high temps, but I believe the Morlina is better suited and higher quality base oil. At 120 deg F the viscosity of both the alternatives is 70 cst.

**JPEROG** · 08-01-2021, 09:48 AM

There is never going to be more torque against the system then with a single application (twins, triples, and quads all have motors to counter act against each other) and are run much lower and with much smaller propellers. My set up is as high as I can go and still get water pressure (my modified case will be another 1 1/4" higher) and I am running a 15" X 34 5 blade merc. cleaver. Mine was fine last time out until it blew a line fitting.

My next project is an LCB with a 300R and a side ram. I am going to use the sea star power assist with a sea star helm and stainless lines as have many times now and see how it acts.

Joe

**Toffen** · 08-01-2021, 10:35 AM

Hi,

So the lesson is to mount a oil cooler in the return line. I will ask my dealer to replace the oil and bleed properly. I have been told that the oil Merc is using is the Mobile One 0w30. I have asked some folks in the oil business in Norway to come up with some ideas.

Would it any point to go back to my old pump? Maybe the added speed and torque from the 450R will create the same problems with the old pump.

Cheeers, Toffen

**JPEROG** · 08-01-2021, 12:19 PM

The new pump was designed because the old one didn't have the capability of keeping the motor straight at speed without being overworked and giving feedback. Keep the new pump just make sure the fluid is correct and put a large cooler in the return line-let us know your results.

Joe

**Toffen** · 08-01-2021, 03:50 PM

Hi!

Anyone out there knowing where to get hold of a oil cooler for the return line?

Thanks

Cheeers, Toffen

**CUDA** · 08-01-2021, 04:35 PM

https://www.seatechmarineproducts.co...-25kw-1in.html
?

**JPEROG** · 08-01-2021, 07:31 PM

https://www.summitracing.com/parts/sum-331000

This is strictly an air cooler. You are not running water to like Cuda is recommending above.

Joe

**river rocket** · 08-02-2021, 04:14 PM

Very timely post. I ordered a cooler today.

In addition, it turns out Merc recommends the 40cc version for single engine boats. The 40cc on a high performance V-hull is slow to respond and difficult to drive. We are going to switch to 50cc.

**Toffen** · 08-03-2021, 07:55 AM

I use a 50CC helm

Originally Posted by river rocket

Very timely post. I ordered a cooler today.

In addition, it turns out Merc recommends the 40cc version for single engine boats. The 40cc on a high performance V-hull is slow to respond and difficult to drive. We are going to switch to 50cc.

**WILDMAN** · 08-03-2021, 08:41 AM

Never once had an issue with the Seastar power assist. The only time I had an issue was the one time I used a Verado pump. Could be the extra heat is because the Verado pump runs full time and the Seastar does not.

**Toffen** · 08-03-2021, 08:59 AM

Thanks

Thats interesting !

Could you send me the model number for the pump? Do you use Danfoss helm (Mercury 40/50CC helm 125Bar/1800 psi). Or another?

Cheeers, Toffen

Originally Posted by WILDMAN

Never once had an issue with the Seastar power assist. The only time I had an issue was the one time I used a Verado pump. Could be the extra heat is because the Verado pump runs full time and the Seastar does not.

**WILDMAN** · 08-03-2021, 09:13 AM

I use the PA1315 or PA1200. The 1315 provides more pressure, but the 1200 works great too. The pump only runs when the wheel is turned. I put them on every single boat in the last 5 years. Probably 30-40. Never had an issue. For twins, I always use the IMCO pump. It does run full time, but I never had an issue with it either. I sell all the IMCO stuff

**Toffen** · 08-03-2021, 10:31 AM

Hi! Thanks again

If I am correct I can only use SeaStar Pro wheel helm with PA1315? Just to be shure I do it right.

Is PA1315 and SeaStar Pro helm compitable with 450R steering cylinder (as Verado)?

Cheeers, Toffen

Originally Posted by WILDMAN

I use the PA1315 or PA1200. The 1315 provides more pressure, but the 1200 works great too. The pump only runs when the wheel is turned. I put them on every single boat in the last 5 years. Probably 30-40. Never had an issue. For twins, I always use the IMCO pump. It does run full time, but I never had an issue with it either. I sell all the IMCO stuff

**MDRURY** · 08-03-2021, 11:18 AM

I run the IMCO pump with twin outboards. I have had it overheat on me one time. After a phone call to IMCO, they told me that if there is not enough air circulating where it is mounted it will overheat and shut off till it cools down. I had sealed all the openings to the back of the boat to prevent Salt water spray from getting back there. He suggested to run a small electric fan blowing on it to keep it cool. Works great now.

I only run the fan when I am racing and putting it through constant stress for extended times. Never has it overheated on any regular day trips or top speed runs.

This is on twin 300xs, but still was able to get it hot enough to shut off on me.

Love the IMCO system and how it feels and responds to the smallest of movement of the steering wheel.

Michael

**WILDMAN** · 08-03-2021, 12:59 PM

You can use either helm. The Pro is rated at 1500 but you don't need the pump to be. I always use a Pro helm anyway though. The only real pressure will be from the pump to the motor, not helm to pump.

Originally Posted by Toffen

Hi! Thanks again

If I am correct I can only use SeaStar Pro wheel helm with PA1315? Just to be shure I do it right.

Is PA1315 and SeaStar Pro helm compitable with 450R steering cylinder (as Verado)?

Cheeers, Toffen