# Thremostart Wiring



## Garthhh (Oct 17, 2011)

2620
I'm trying to troubleshoot the system before replacing the Thermostart
there are 2 wires 
one black with a spade terminal
one green with a bullet connector
Black wire has 12vdc with key in TS position
green wire no power in any position or connection to ground?


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## winston (Aug 19, 2008)

Wire spade terminal to spade terminal on thermostart. If all gauges and lights are working put tape on the bullet connector. http://www.hoyetractor.com/PROD/TS-1.htm


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## Garthhh (Oct 17, 2011)

I changed out the thermostart
it didn't help 
still hard to start?
the new thermostart seems to function, the intake feels slightly warm
this 2620 has high hours
after changing the oil last year
starting became very difficult
I have to remove the air filter & add a spray of starting fluid
I replace the filter & use normally
no problems starting the rest of the day

I used 15-30 rotell oil, adding restore additive helped slightly
the battery will crank the starter for extended periods
new ground wire, new end for the positive wire
I added injector cleaner & ran ten gallons of diesel through the tractor, no improvement

will adding kerosene help starting?
heating the block with a space heater helps when the temp is under 50degrees

short of a rebuild, any suggestions?


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## harry16 (Dec 8, 2011)

Apply more time to heating the thermostart. Maybe 30 seconds, or more. 

Sometimes with old worn diesel engines, cranking speed becomes very important, as you lose compression with slow cranking. Make sure all your battery and starter connections are clean, including ground connections. Check battery cables for internal corrosion. Does your starter sound slower than in years past? Clean the starter mounting faces for better ground. Maybe your battery isn't as strong as it should be? Maybe replace starter?


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## winston (Aug 19, 2008)

Overhaul seems in order. Might need a compression check to confirm. 

Be very careful with the starting fluid. I have read of numerous piston lands broken on these engines because of it. An example: http://www.tractorbynet.com/forums/...525981-ym2000-piston-i-think-i-0620091413-jpg


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## Garthhh (Oct 17, 2011)

thanks for the suggestions
who would be a good source for rebuild parts? or short blocks?


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## winston (Aug 19, 2008)

http://www.hoyetractor.com/ Not likely to find short block. Pretty much have to buy individual parts for these old grey Yanmars. Rebuild kits are not available.


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## Garthhh (Oct 17, 2011)

thank Winston


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## bmaverick (Feb 20, 2014)

Garthhh said:


> thanks for the suggestions
> who would be a good source for rebuild parts? or short blocks?


The 2620 has the 3T84-NC. The 3T84 series of engines have many interchangeable parts, with slight configuration differences. You could contact Fredricks for a 3T84-NC or what ever of the 3T84 series that is swapable to the YM2620. However, A freshly rebuilt like new engine and shipping to CA may be cost prohibitive vs. getting a another tractor. 

Sure, Hoye, Fredricks and other gray Yanmar parts places can help you out to rebuild the engine with components, the question is, do you want to spend the time digging into something that may end up being a money pit? 

On my old JD850 with the Yanmar 3T80 engine, it was messed up running when I got it. After two weeks in the diesel shop, it had a cracked head and cracked block. Thus, the cost to weld it with taking a risk was not worth saving the tractor. Instead, I found Fredricks and did a trade-in.


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## Garthhh (Oct 17, 2011)

I'm not in a hurry to throw good money after bad
I only put a couple of hours a month on it

some more observations
the new thermostar actually made it harder to start, [longer cranking time]

starting fluid on the air filter seems to plug it, so I remove long enough to start

when I bought the tractor it had dupont imr 4895 as an oil additive

bad stuff can happen with starting spray/fluid
more a 1 second shot greatly increases the chances of an expensive incident

I don't know how bad the cylinder or crank look
which would determine how extensive of a rebuild would be required

how would I determine which blocks would bolt up?
there's lots of good stuff/junk available in central california...


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## winston (Aug 19, 2008)

Not sure why you would be looking for a block to bolt up. Overhaul of your engine might be the best route. Are you mechanically inclined?


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## Garthhh (Oct 17, 2011)

I'm very mechanically inclined
but 
I have too many projects & too little time

I would consider new rod bearings & rings
not familiar enough with yanmar tendencies
would I find a ridge in the cylinders?
would the crank wear or just the bearings?

side note the starting fluid is not ether, it's a combination of propane, butane & co2
I installed a ball valve on my old thermostart plug
this allowed me to spray a 1/2 second shot of starting fluid with out removing or fouling the air filter


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## winston (Aug 19, 2008)

I don't know whether you would find a ridge. The cylinder liners are replaceable if needed. I would be suprised if you find crank wear.


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## Garthhh (Oct 17, 2011)

thanks Winston
good info
could I do a rod from below?

I ask about what might bolt up
6 months ago there was a JD 850 with a partially blown trans for $500
things like that pop up from time to time
the yanmar [trans]set-up is superiour to most in ease of use


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## winston (Aug 19, 2008)

As far as I know all the greys can have pan and head removed in place. If you have a loader the loader frame might have to be removed if it would interfere with the pan.


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