6410 thermo start

[MarkOntario]

Hi all, I have a '91 6410 with the thermo start. Yesterday I took the hose off the intake manifold, my son in the seat was "glowing",
that part works, it glows great but no little fire, there is no fuel dripping on the spiral I think.
How is the fuel moving without the motor running?, There should be a little fire ?
My TW15 gives a little " woeshhhh"(fuel explosion) @ 45-50 seconds glowing, the 6410 doesn't do that.
Any ideas welkom.

Mark

 

[sotxbill]

Should be a fuel line on the thermostart, that goes up to a tee on the return fuel line. As fuel is returned to the tank, it go through the tee and back down to the thermostart. That short piece of line is a reservoir for fuel for the thermostart. Make sure line is clear and fuel dribbles out of it when the tractor is running. I have seen thermostarts that would not fire but only glow. Some I fixed buy working a probe against the spring loaded ball and loosen it up.. Others I had to replace. On the fuel side, push a small screwdriver into the hole and push on the ball bearing a couple of times and then see if it heats up and finally releases fuel into the manifold and burns.

 

[MarkOntario]

On this tractor the fuel line to the thermo start comes direct from the rotary fuel pump.
I never knew there was a ball/spring in it, will check that out.
Thanks, Mark

 

[sotxbill]

the line must be located where is is gravity fed from the return line. that way it will hold a bit of fuel and act as a reservoir. the bleed line from the injector pump should go up to the return on the injectors and then up towards the tank where the tee is located..

 

[sotxbill]

Your newer tractor may have an electric fuel pump that supplies fuel different than the previous models.. either way the fuel line to the thermostart must supply fuel. The older models were gravity feed from a tee into the return line. Even earlier ones had a small canister or reservoir that held fuel. ie the 5200 had the reservoir at the tee to hold extra fuel.

 

[psimmer]

I can't help at all with your question, but am curious as to how effective these are. I know about them, but have never used them. For example, when they are working correctly, how much lower temperature is effective at? For example, if it starts down to 40 degrees with no assist, do you gain say maybe down to 20 or 25 degrees? Thanks.

 

[Dwayne F]

Sorry to butt in on this post, but I have a small fuel line which I think is on the other side of the tee which I hoping is the return that's been referred to in this post coming down to the bottom tank on my 7710. It has a "check valve"(I'm guessing) just as it goes in under the cab. In the past the fuel line between the check valve and the little "Tee" or "block thing" has been patched more than once by the looks of it, and is now weeping in a split above the check. Is it safe to say that I can just remove all the old line from the tee to the check valve without too much of a fuel spill...My concern is..will it syphon from somewhere ? I'm trying to get the line in hand to go to the local auto shop for a replacement to get the correct size and length...Sorry for the long winded post.

 

[sotxbill]

Yes you should be able to replace all the lines. the injector pump and injectors need the return line open and working. They will pass excess fuel back to the tank or in some cases the filter. If this line is plugged it can cause starting problems and worse. The injector pump will not prime correctly and get air lock. Normally very little fuel will run out when replacing the lines.

 

[Dwayne F]

Thanks Bill, I just had to cut the end back a bit and reassemble...Good to Go..only one more left, a dripping lower radiator hose..btw..My wife says to me a bit ago.." I see you're working on your Harley today... " of all the nerve.