[Dominic Maionchi]

I have a lot to learn. i finished the install and started the engine and put the boat in gear and ran it to about 2600 rpm at the dock and the exhaust temperature shot up to 780! and the boost was around 7-8.

I didn’t want to go higher at the dock but will give it a test run soon.

what temp should i be looking for?

[Dominic Maionchi]

ok im starting to understand

ill order new blades. ill get flexofolds recommendation, even though they recommended this size in the first place.

off the top of your head, do you think its better to adjust by making the diameter of the prop smaller, or changing the pitch?

i’ve read that changing the pitch makes the prop less efficient.

[Dominic Maionchi]

about 1.5 gallons per hour.

yes im only using about 30 hp.

So I’m not hurting the engine cruising at 2500 to 2800 rpm depending on sea state, even though i’m overpropped across all rpms, right?

i can change the 4 blades on the propeller hub with blades with less pitch to get to 3850 at wot. what advantage would i get in doing so?

dom

[Dominic Maionchi]

tony
i ordered the pyro/boost guage last night.

any thoughts on the prop sizing?

do you agree with rob that as long as i cruise at 2500 at 8 knits im not damaging the engine through overload?

dom

[Dominic Maionchi]

you wrote: but if you stated that you cruise the engine just over thermostat opening temperature, something like 1,200 or so then you’d probably be safe as is.

I cruise at 2500 rpm as per the guage at about 8 knots. How does this equate to therostat opening temperature?

[Dominic Maionchi]

im going to check ccuracy of tach again. my eyesight may have failed me in the bilge. it must be 50 rpm off across the range. two of the readongs must be mistakes. so at 2500 on the tach must be 2450.

so i can do approximate hull speed at 2500. However, after reading the articles on overpropping if the engine is overloaded at wide open throttle wouldnt it be over propped across all rpms?

dom

[Dominic Maionchi]

2500 rpm at 8-8.5 knots

i posted the accuracy results above

[Dominic Maionchi]

great. thank you. ill order the guage tonight on your website.

any thoughts on the prop?

[Dominic Maionchi]

is the prop overloading the engine? i have a 4 blade folding flexofold prop. if its oberloaded can i ask flexofold for different pitch blades?

where do i install the boost and temperature sensors?

thanks

dom

[Dominic Maionchi]

Instrument tested with LED instrument on cranck

1000 1030
1500 1350
2000 1985
2500 2350
3500 3450

seems accurate

[Dominic Maionchi]

Here are the results:

Wide open throttle in neutral: 4,400 rpm

Wide open throttle in gear: 3,500 rpm

Engine rating: Maximum output 100 hp at 3800 rpm (see attached for Yanmar 4jh3-hte)
https://www.simplicity-marine.com/pdf/Yanmar/JH.pdf

Test results with clean bottom.

RPM Speed over Ground measured by GPS

1500 5.9
1750 6.4
2000 7.0
2250 7.3
2500 8.7
2750 9.1
3000 9.4 with very light white smoke
3250 9.7 with light to moderate white/grey smoke
3500 9.7 with moderate darker white/grey smoke smoke

[Dominic Maionchi]

mixing elbow looks like it has a plug in it. 3rd picture

exhaust manifold looks like it has a plug on it. 4th picture.

intake manifold looks like it has a plug on it. 6th picture

can i use any of these?

if so how do i go from metric to your 1/8 npt?

dom

[Dominic Maionchi]

to answer your question about the application, there is no special application at all. i would just like to moniter these two parameters. its a 50 foot sailboat. ive recently put a new prop on it. i am still not certain that its the correct size. it may be slightly overpropped. I will test it again this coming week more thoroughly with a clean bottom. I will also check if the rpm meter is accurate. i will also ckeck the wot in neutral. my records from my last outing with the new prop showed 3700 rpm at wop; the yanmar specs show it should be 3800.

i am getting some very very very light white smoke from idle through the mid rpm range and then some additional white smoke at 3000 and then again more at wot, never heavy. i do not know why yet. if the engine was over propped and thus overloaded woulldn’t it be black smoke? could it be a bearing leak on the turbo?

i thought knowing the exhaust temp would help me diagnose problems like this and also give me early warning signs of future problems.

i bought the boat in puerto rico and sailed it back motoring all the way up the coast from panama to san francisco. i have a lot of hours motoring. I’m planning another trip soon to alaska and want everything in order first.

[Dominic Maionchi]

forget the stock photos. they are different.

[Dominic Maionchi]

i will send the actual pictures of my engine when i get to the boat.

[Dominic Maionchi]

yes turbo and intercooler

are these two stock photos ok?

[Author]

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