Descaling/cleaning

[Speedling]

Anyone got bright ideas on flushing engine to clean insides well?
I had some overheat warnings so i pulled my thermostat and while not bad i'd like to have a bit more peace of mind. About to let my thermostat soak in a diluted vinegar solution for a short time and then brass brush it. But all the internal parts?
I'm afraid of using something too corrosive and have heard that vinegar can damage aluminum.
I have half a container of salt away that I will be using asap for starters

 

[lazergeek]

Setup a small kiddie pool under the pumps. Get some marine descalling solution and a pump, fill the pool with descalling solution and recommended water then connect the pump to your flush ports and pump the solution while running the engines.

 

[FSH 210 Sport]

You need to check your thermostat in hot to make sure it opens fully, this test is usually illustrated in the service manual.

 

[FSH 210 Sport]

Here’s the thread @CrankyGypsy did on descaling his engine… but looking at the inside passage of your thermostat housing I don’t see much stuff in there. The minerals I see on your components looks it’s deposited in places where the water just sits and doesn’t flow. Since the other engine is giving you any overheats at this time I’d try a new thermostat and see if that solves your issue for at least the rest of the season. Perhaps there is some scale keeping the thermostat from opening fully but thermostats do fail over time

Thread 'Closed-loop flush of MR-1 with Marine Descaler'

Feb 23, 2016

i solved an intermittent overheat on one of my engines due to a bad thermosensor (https://jetboaters.net/threads/bad-thermosensor-intermittent-overheat.8032/), but am still getting overheats on both engines during WOT runs over ~5 miles. i suspect that the issue is scale build-up inside the water jackets, particularly calcium carbonates. both engines are doing the same thing at the same rate, so i'm ruling out electrical issues. my temp readings are showing a particularly hot area of the starboard motor around piston #1, leading me to believe there is a mass of calcium/sand/salt...

• CrankyGypsy
• Replies: 29
• Forum: Member Tips and Ideas

• 
• 

Descaling document;

CrankyGypsy

 

[Speedling]

Thanks guys! Good info here. At work now but I agree it's not like i have a lot of buildup. We bought boat from someone that did brackish and salt water so we did saltaway a few times a year originally and again a few times after bimini run 2018. Our first long run after purchasing was the starved rock to peoria and back. Wehad an overheat then. I believe it was the other side and i replaced the thermostat. Since i am into it i may replace both after cleaning them up.
I like the descaling idea after seeing some of the carnage others have had. My anodes on pumps and engine were checked before this year's bimini run and all looked good. So good in fact that i didn't replace one of them on motor and have a spare.
So after doing all this I may pull the pump screen even though all 4 pee holes were clearly flowing proper volumes.
The exhaust may get taken apart a bit as well just to see if anything obvious is going on and if so i dig deeper.
Meanwhile my wife is like,uh, we should go to Shelbyville this weekend! And don't forget the gary air show is coming up!" And "we haven't done a run up into Michigan yet this year!
And lastly i will look at the sensors that may be cuprits.

 

[FSH 210 Sport]

Right on…. Just looked again at the picture you posted and there is like no scale build up in the passage….

 

[Speedling]

https://a.co/d/3povtiB

This amazon link look like the right one? For some reason they are $17 instead of like $47

 

[Speedling]

Interestingly the one in there is a 50 degree celsius one. Not 60 as linked by others before me

 

[Speedling]

Thermostat bench tested perfectly at the 50 celsius.
Reinstalled and ran salt away on both motors. My wife, my youngest(he's my mechanically inclined one and usually helps me) and myself all agree they both sound rough.
Like rough idle.
Did a batch of salt away using the dispenser on both engines so like 3 minutes or so run time on the hose.
I am curious on the spark plugs.
I learned that ngk has some plugs not from the ngk factory anymore and they put the ngk labelon it. I have come across plugs for work that were broken for the first time.
I also did iridiums this spring knowing they would hold up to salt water better.
Hope to swap the motor that overheated and run another salt away batch through.

Side note my hose has a repair end and it sucks. Different hose tomorrow.
Second side note: time to take pumps apart and regresse/inspect. I think some of what we hear could be pumps rattling a bit. It's been a few years since i pulled that nose cone and greased.
All the good things that should be done anyways i guess.
Maybe a little overheat scare is what i need to get it back to beautiful mechanically just like we did to the interior and exterior

 

[FSH 210 Sport]

From a thread I did on NGK plugs a short time back…

Next I asked her (NGK csr) about the plugs having the translucent or cardboard protectors. She told me that the plugs with the plastic covers are made in the USA, and the ones with the cardboard are made in Thailand or one of the other countries that makes them.

Thread 'NGK CR9EB spark plugs'

Jan 25, 2025

I recently posted about pulling my plugs at 250 hours and I replaced them with plugs I had on hand, I used a super thin coat of anti seize and the service manual torque of 9.6’ pounds or in my case, 115” pounds since I have 1/4” drive inch pound torque wrench for small things. When I woke up in the morning I didn’t have a good feeling about that, even though its what I had done in the past, and I’ve learned not to ignore my intuition as it were. Which resulted in a big dive, Aka fell down the rabbit hole on spark plugs.

NGK is now Niterra

The TR-1 engines take the long skinny CR9EB...

• FSH 210 Sport
• Replies: 3
• Forum: General Discussion

• 
• 

 

[Speedling]

From a thread I did on NGK plugs a short time back…

Next I asked her (NGK csr) about the plugs having the translucent or cardboard protectors. She told me that the plugs with the plastic covers are made in the USA, and the ones with the cardboard are made in Thailand or one of the other countries that makes them.

Thread 'NGK CR9EB spark plugs'

Jan 25, 2025

I recently posted about pulling my plugs at 250 hours and I replaced them with plugs I had on hand, I used a super thin coat of anti seize and the service manual torque of 9.6’ pounds or in my case, 115” pounds since I have 1/4” drive inch pound torque wrench for small things. When I woke up in the morning I didn’t have a good feeling about that, even though its what I had done in the past, and I’ve learned not to ignore my intuition as it were. Which resulted in a big dive, Aka fell down the rabbit hole on spark plugs.

NGK is now Niterra

The TR-1 engines take the long skinny CR9EB...

• FSH 210 Sport
• Replies: 3
• Forum: General Discussion

• 
• 

I appreciate that thread for sure! My boxes were plain white, no description or writing at all. I have one more 4 pack and am getting into that tomorrow.

 

[Speedling]

This is what i have. I am going to check my amazon purchase and see if labeled NGK and leave reviews appropriately.
Heat warnings today and 102 heat index so may wait till near dark to start if I do anything.
Convenient black plastic wrapper they had around the box though.

 

[FSH 210 Sport]

This is what i have. I am going to check my amazon purchase and see if labeled NGK and leave reviews appropriately.
Heat warnings today and 102 heat index so may wait till near dark to start if I do anything.
Convenient black plastic wrapper they had around the box though.

Those look like Chinese knock off NGK plugs. NGK plugs come properly packaged with the company logos.

 

[FSH 210 Sport]

this here is a certified seller for NGK spark plug, I think I put that in the thread that I did on them. Your engine probably uses a different plug than mine, but this distributor is certified, the plugs come in NGK labeled packaging.

Amazon.com: NGK 6955 CR9EB Standard Spark Plug, 4 Pack : Automotive

Buy NGK 6955 CR9EB Standard Spark Plug, 4 Pack: Spark Plugs - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Speedling]

this here is a certified seller for NGK spark plug, I think I put that in the thread that I did on them. Your engine probably uses a different plug than mine, but this distributor is certified, the plugs come in NGK labeled packaging.

Amazon.com: NGK 6955 CR9EB Standard Spark Plug, 4 Pack : Automotive

Buy NGK 6955 CR9EB Standard Spark Plug, 4 Pack: Spark Plugs - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Yeah kinda like these for my mixers