Potential Robin Engine Cold Start Remedy

[duane]

Have a potential remedy I thought of last night on the Robin Engine cold start difficulties:

Just a note, I have not tried this. So proceed at your own discretion.

Here is my cold start set-up along with synthetic 5W-30 oil in the engine, dino 10W-40 in the hydraulic tank. I use two magnetic block heaters, one 400 watt, one 200 watt on the hydraulic tank for about 2 hours. Approximately 15 minutes prior to starting, I turn on a 35k Btu torpedo heater blowing into the engine compartment, and move the 200 watt heater to the tram pump. This works reliably down to 10F. Below that, it still is a chore to start. I do not like this process; it takes time and the fire risk of having the hot torpedo heater blowing into the engine compartment.

My idea was to use starting fluid without the hassle of disassembly of the air cleaner each time. I would remove the air cleaner cover; the only real function is as a shroud to pull air from the engine fan side. This ensures cool air, but in the winter, this is not necessary. Actually a small engine mechanic told me to remove the air cleaner cover in the winter so that the warm air on the muffler side of the engine would mix with the cold air to promote better gas vaporization.

Take a spare air filter, or the one from the engine to the workbench. Drill a clean 1/8" to 3/16" hole in the air cleaner metal plate near the center. It needs to be near the center so that the straw on the starting fluid can will spray into the throat of the carburetor. See Pixs, hole should probably be located at the front.

Remount the air cleaner with the air cleaner cover nut. Secure into place. Now the part I struggled with was how to cover this hole to prevent air from bypassing the air cleaner through the drilled hole. It's probably not a big deal in the winter since there is no dust (snowblowers do not use air cleaners). Then I had this idea, place a small round magnet over the drilled hole. See Pixs. This is easily removable to spray in starting fluid, and then replace to prevent air bypassing the filter element.

Go to the regular set-up for the warmer temperatures.

So the winter start procedure would be:

1 Open engine cover
2 Remove magnet
3 Spray starting fluid for a count of three. I have starting fluid that indicates that it has an upper cylinder lubricant
4 Replace magnet
5 Close engine cover
6 Apply choke, not sure if you need full choke or about 3/4's. I know as soon as mine starts, I have to back off the choke or it will stall.
7 Set throttle at full
8 As soon as it starts, I am backing down the throttle so the engine does not race to full speed.
9 Allow it engine/hydraulics to warm up

Any negatives. I have not researched the negative affects, if any, of using starting fluid on these type gas engines. I would think if the engine starts well with this procedure, then it is a lot less stressful than continued cranking and backfiring, but please help me vet this out prior to trying.

 

[ldabe]

Duane,

If you don't mind me asking, where is your location?

Also, this sounds pretty good. I am not very mechanical, so I really don't have any valued input.

Btw, what year is your PT425? I have a 422, it is a 2003.

Thanks for posting.

PS. The battery kept on a drip charge has helped, but it still takes to long of a crank to get it running.

 

[duane]

Idabe,

I'm in Northern New England. I have a 2001 PT422.

I put a battery charger in the 'start mode' when really cold. It helps with cranking, but still backfires and is hard starting.

Just as a note to my post, I would only use starting fluid below 10F, not everytime. I did a google and there seems to be a lot of negative opinions on the use of starting fluid. I'm not sure if it is folklore or the real truth.

 

[ponytug]

The general problem with starting fluid, aka ether is that it is self igniting when compressed. If you get too much in your intake manifold, you can get premature detonation, aka knocking. If it is bad enough, as in too much fluid, you can get enough of a bang to damage the piston and/or cylinder head. Used in small amounts, on a cold engine, without having any accumulate in a liquid form in the intake manifold, you would be OK. c.f. the dozers that have it built in. (Which also limits how much gets dispensed...)

So, yes, it can be really bad, but if used properly, no problem.

It also has a tendency to wash lubrication off of the cylinder walls if you get liquid into the cylinder, rather than just vapor.

Personally, I prefer to go the route of preheating the engine and/or the air. It is much harder to destroy your engine. (Search on the cummins diesel air preheater, or look at what deutz does with for the PT diesel engines. Either route would work.)

All the best,

Peter

Idabe,

I'm in Northern New England. I have a 2001 PT422.

I put a battery charger in the 'start mode' when really cold. It helps with cranking, but still backfires and is hard starting.

Just as a note to my post, I would only use starting fluid below 10F, not everytime. I did a google and there seems to be a lot of negative opinions on the use of starting fluid. I'm not sure if it is folklore or the real truth.

 

[catsco]

I have a Kohler engine which can be hard to start below 20 degrees.

It's kept in a round-top fabric shelter to keep snow off, but can't be heated.

So, I've discovered that if I put a small tarp over the engine compartment and a 1500 watt heater under it (always set up the night before) and run the heater for about 1/2 hour, it starts like it would on a 75 degree day.

This is not a lot of work compared to the starter fluid, battery jumping, and general misery I tried first.

Mark H.

 

[duane]

Ponytug and Catsco:

Great comments, I think I will try the tarp over the engine compartment tip.