Yanmar 4JH3-TE 75hp AND 4JH2-HTE 75hp the differance between these two engines

[ski69sail]

Hi And Thanks
My current yacht has the Yanmar 4JH3-TE 75hp , And I have purchased a seperate 4JH2-HTE 75hp to pull apart and play with in my own time in the garage. I also intend to keep it as a source for spair parts.
I believe they are very simular yanmar motors , but im hoping someone knows something that can help ..

[skipperpete]

Originally Posted by ski69sail

Hi And Thanks

My current yacht has the Yanmar 4JH3-TE 75hp , And I have purchased a seperate 4JH2-HTE 75hp to pull apart and play with in my own time in the garage. I also intend to keep it as a source for spair parts.

I believe they are very simular yanmar motors , but im hoping someone knows something that can help ..

Here’s the chronology of the JH series and while I’m warily confident that some parts are interchangeable many other parts are not. Heat exchanger housings might be but low hp JH had a 2 pass tubestack and the higher Hp used a 3 pass stacks the cores and end caps were different. Injector pumps changed from inline to rotary, injector nozzles with different spray angles , injector pump drive gears with auto advance and there was a thread on this forum about water pump">raw water pump drive gear incompatibility recently. To use parts across different series would require a forensic search of both parts catalogues. [ATTACH]26799

[ski69sail]

Thanks Heaps.
So the other option was to recondition the 4JH2-HTE in the garage And keep it as a spair.
Im thinking that the worst that could happen is that atleast Ill actually learnt about the finer points of the motor. And possibly onsell it at no loss ???..at a later date.
Ray

[skipperpete]

The finer points of your two engines are almost identical, fuel system, overhead gear, turbo, heat exchanger...if you learn one.....you’ll understand the other. Both are good reliable models.

[ski69sail]

Thanks Skipper Pete.
Your opinion gives me lots of encouragement..Playing around on my actual yacht motor is very stressful... So haveing another motor to break is sounding like an OK idea. There is also a gearbox...

.

[skipperpete]

Originally Posted by ski69sail

Thanks Skipper Pete.
Your opinion gives me lots of encouragement..Playing around on my actual yacht motor is very stressful... So haveing another motor to break is sounding like an OK idea. There is also a gearbox...

.

Money well spent, you won’t regret it. Please try and post your stories about the “training engine” so we can all benefit.

[ski69sail]

Hi Skipper Pete
My wife thinks its also a wonderful idea ... except for the cost..Sorry yet another and another and another cost...

I dont intend to sell this vessel ... so it feels like a cheap up front cost when divided by time ,knowledge and spair parts over another 20 or 30 years...God Willing....

[Ericson38]

Originally Posted by ski69sail

Hi Skipper Pete
My wife thinks its also a wonderful idea ... except for the cost..Sorry yet another and another and another cost...

I dont intend to sell this vessel ... so it feels like a cheap up front cost when divided by time ,knowledge and spair parts over another 20 or 30 years...God Willing....

I have a 4JH2-HTE. The series is all 1.8 liter.

The original 4JH series is 1.644 liter, (78 mm bore).

The 4JH3 series are 1.99 (2) liter.

The bore of the 4 JH3s is 84 mm, while on the 4JH2s it is 82 mm. The 4 JH4s are 2 liter also, but 4 valve heads with the bridge actuator.

[ski69sail]

Hi Ericson 38

Thanks for your interest...Are there any other differances that would be worth menchining............ thanks heaps Ray

[Ericson38]

Originally Posted by ski69sail

Hi Ericson 38

Thanks for your interest...Are there any other differances that would be worth menchining............ thanks heaps Ray

I'm sure there are more, but the biggest that stood out to me when downloading the parts and repair manuals was the bore-stroke values.