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Scag Tiger Cub SMTC with Briggs 26HP will not start in cold weather. The engine will not turn over fast enough to start. The dealer claims the oil viscosity is to heavy for the weather. I'm using the oil recommended by Scag. This was no problem when it was new,it started fine in the cold.This is the second season of operation .Installing a new battery didn't help. Has anyone else had this problem?

essikr said:

Scag Tiger Cub SMTC with Briggs 26HP will not start in cold weather. The engine will not turn over fast enough to start. The dealer claims the oil viscosity is to heavy for the weather. I'm using the oil recommended by Scag. This was no problem when it was new,it started fine in the cold.This is the second season of operation .Installing a new battery didn't help. Has anyone else had this problem?

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I'm not much of a small engine mechanic, but I don't think its the oil and you have eliminated battery problems.

Double check your battery terminal connections and then the only thing left is the starter. It sounds like something may be gumming up the starter drive and keeping it from turning full speed.

If its easy to pull the starter, that's what I would do and see if the starter drive is turning freely when out of the engine.

If its not gummed up or too dirty to turn freely, then there's the possibility that its just a bad starter, but that should have shown up during warm weather, too.

Just as a curiosity, what winter temperatures are we talking about and what viscosity of oil are you using? Also, are you using any additives such as STP oil treatment?

Tempertures in the 30-40 ,I was using 30 weight .I changed it today and put 10w 30 ,no additivesin. I didn't think it was the oil either. I'm going to pull the starter and check it. I'm thinking the starter is pulling to many amps ,going to have it tested when I get it off.Hopefully it just may be gummed uplike you menthoned. Thanks for the reply

What is the cold cranking rating of the battery?
I just had the same problem with my TC/Briggs and I realized that I had 30w oil in the engine. I drained and refilled with 5W-30 full synthetic and had to change the battery which was 5 years old.
Another problem is dirt in the plug in connectors, which I periodically disconnect and clean. you need to disconnect the battery before doing so. I did add another ground cable from the battery ground terminal to the engine ground. Check the engine grounds on the mounting bolt.
Briggs has changed to another starter motor with a different part number, but I don't know why. Lack of lubrication in the starter motor bushings is another possibility, I just serviced a Toro/Kawasaki ZTR with a cranking problem and found the starter dragging while cranking and the customer gave me the go to replace it, 11 year old machine with 500 hours. It still had a starting problem, I replaced the ignition coils and it ran perfectly.
Bear in mind that while the engine is cranking, it has to turn two pumps that have 20W-50 oil in their hyd system so a fully charged battery of the correct cranking amps still has it's work cut out to turn all this fast enough when cold to make spark.
ZTRs generally are not cold weather machines and I let mine warm up for 10-15 minutes before using.
I'm done for this season and will be storing it for the winter.
Mad Mackie in CT:smile::laughing::biggrin:

If the oil is part of the problem,does anyone know if they make a dip stick plug in heater. Something similar to ones made for cars? The mower will be put away in a week so any improvements made will be for next season's cold weather.Here in Ohio you never know what your gonna get ! Thanks for the replies.

I do not recommend a dip stick heater as the oil level is only about 2 1/2" and the dip stick tube is plastic. I know several that use their ZTRs in winter with a snow plow but the machine is kept in a heated garage ready for use.
With all things normal, it should start down to freezing. I used my TC last fall in cold weather to do some customer fall cleanup but it did crank noticably slower.
My new battery is a 425 CA, 350 CCA and I charged it before putting it into service. To my knowledge this is the highest capacity available in the garden tractor size battery. There are deep cycle batteries available in this size but they don't have the cranking capacity needed for hydraulic ZTRs.
Mad Mackie in CT

If this is an OHV engine I would check the rocker arm to valve clearance. This should be checked and adjusted every couple years and if the clearance is too wide, it could be the cause of your problem.

I went out into my cargo trailer this AM and my Tiger Cub/26 Briggs started right up no problem, temp was 34F. Last time it ran was Monday.
I'm going to clean it up, service it, replace the blades, put it in storage, run the carb out of fuel, drain the fuel tanks, and remove the battery for use in my Ingersoll GT for winter, in spring I'll buy a new battery for it.
Mad Mackie in CT:smile::laughing::biggrin:

I want to thank everyone for their input. When I went to remove the starter I think i found the problem.The 12v cable at the starter was not tight.Looking at it ,it appeared to be OK. When I went to loosen the nut it was already loose. I took the nut off , cleaned the connection and put the cable back on properly. This morning 30 some degrees it started up like it is supposed. The lesson here is to check the simple things first.

essikr said:

I want to thank everyone for their input. When I went to remove the starter I think i found the problem.The 12v cable at the starter was not tight.Looking at it ,it appeared to be OK. When I went to loosen the nut it was already loose. I took the nut off , cleaned the connection and put the cable back on properly. This morning 30 some degrees it started up like it is supposed. The lesson here is to check the simple things first.

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I'm glad you fixed your problem!! :thumbsup: Nice work!

essikr said:

I want to thank everyone for their input. When I went to remove the starter I think i found the problem.The 12v cable at the starter was not tight.Looking at it ,it appeared to be OK. When I went to loosen the nut it was already loose. I took the nut off , cleaned the connection and put the cable back on properly. This morning 30 some degrees it started up like it is supposed. The lesson here is to check the simple things first.

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I'm glad it worked out well for you.

As an aside, I use 10W-30 synthetic in all my mowers year round.

Glad you found the problem. The battery cable stud on the starter motor is a fairly common problem.
For years this stud has been problematic on some brands of starter motors as it snapped off from over tightening. In time as the radial serrations push into the copper cable lug, the nut will become loose.
I'm going to service my Scag Tiger Cub and put it into storage today.
Later
Mad Mackie in CT:smile::laughing::biggrin: