# GT5000 Craftsman w/B&S 26HP Hard Starting



## Urick (Mar 26, 2009)

Hi all. A little history of this machine. This series of engine is the one which has the leaking air intake problem, but mine hasn't exhibited this problem as of yet.This tractor is used primarily for lawn mowing and uses a 48" cutter deck. It has been well maintained with no running problems. But it has a curious problem which I cannot pinpoint. I mow an acre grass every week to ten days in season and the tractor/engine runs fine once started. 

The problem is that it is very hard to start! After it sits for a week or so, I have to get a industrial strength battery charger to assist the regular battery (btw the battery is a new heavy duty Die Hard that holds charge). At first even using a booster charger to assist, the engine will not crank! By goosing intermittantly and multiple attempts, it starts after about 10 minutes or so. At that time the engine will crank and start quickly. Once it warms up, you can cut off the engine and it starts flawlessly without any extra assistance. But cold starting is an arduous process. I am concerned that the starter may have a dead field coil or open rotor. But since the starter whizzes along after the engine is warm, I suspect it may be a valve adjustment problem. Also at present single weight 30W oil is used and the filter replaced every oil change.

Has anyone here seen a patient with such symptoms? Any help appreciated.


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## SABL (Jul 4, 2008)

I was going to ask about the oil but I see you listed it. 30w should be fine depending on outside temps..... don't know if multiviscosity is recommended. 

The "dead spot" with the starter should not change by applying more power and will only improve by moving the armature away from that area (where it came to rest). 

The problem may lie in the connections......especially the ground wires or even the actual mounting of the starter. A plus + or positive charge will readily make the jump if the negative side is good. Lawn equipment is often exposed to moisture and corrosion may be your problem. Inspect all connections in the starting system to make sure all is clean and tight. Vibration from a running engine may loosen the corrosion enough to provide a working circuit that will be lost after a few days of idle time.

A new battery is no guarantee..... some units can be defective. Just another thing to check..... I do not suspect your battery. From the application of additional power I am going to suspect a bad ground or perhaps worn/sticking brushes in the starter. 

Long story short..... check your connections and the starter mount to make sure all is clean and tight. Apply dielectric grease to combat corrosion and loss of connection or a break in the circuit.


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## Urick (Mar 26, 2009)

Yes indeed sometimes new batteries are bummers too, but I don't think this one is. I have visually inspected the most obvious electrical connections, from battery through the solenoid switch to the starter connection. However I haven't examined any of the starter attachments that may provide the grounding circuit. The engine is fairly clean with minor accumulations of dust and dry clippings. I certainly hope that is the problem as I would hate to get into adjusting valves and the like. I'll keep the situation updated as things happen.


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## Urick (Mar 26, 2009)

Electrical circuit tested today. All connections were tight and with no corrosion. I further tested starting circuit by placing ammeter in circuit and voltmeter across the battery. With the starter trying to rotate engine, the battery voltage was around 9.5 Volts and the current being pumped into the circuit was 350 amps. This puts circuit impedance at 2.7 thousandths of an ohm and I think that is pretty good. Voltage across the starter switch was 0 volts when trying to start. Likewise that is good. I am going to change the oil to a synthetic in hopes of reducing the necessary effort to turn the engine. Again once started the motor runs smoothly and with good power to the mower. Later


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## MrChooks (Apr 19, 2008)

:wave: Urick - I doubt that valve timing is the issue - but would recheck every connection in the start circuit - by that I mean remove every starter motor lead, emery the connection faces and reinstall. Even though connections are tight - they can still be high resistance joints if the surfaces are not spotlessly clean.

If that doesn't fix it - try stripping the starter motor - gently emery and clean the commutator and see if a new set of brushes helps.

If these don't work - then I would strip and clean up the contact surfaces or the starter solenoid - else try a replacement one.


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## Urick (Mar 26, 2009)

Sounds reasonable. The starter is fairly easy to access and an investigation of its internals is in order. Brushes are definitely a suspect. I have suspected the solenoid power contacts but the current test pretty much eliminated the suspicion. I am still not sure about the coil that engages the solenoid, maybe it doesn't have the force to put the main contacts in securely. Regardless, I have run an experiment the last 4 days. After sitting a day, I attempt to start the machine. It hesitates once and on the subsequent twist of the start key, the engine whirls quickly and starts. Sitting a week it reverts to the 10 minutes of aggravation.


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## MrChooks (Apr 19, 2008)

:wave: High resistance joints generally only show up under high current loads - so are hard to test with a multi meter:sigh: unless you can measure the voltage drop under high current loads 

If it were my mower - I would check and clean every high current cable joint, the next suspect would be the contact surfaces of the solenoid (these can get burnt over time and hence start making poor contact = high resistance link ) and if all that fails - then look at the starter motor commutator and brushes - I am fairly sure that the problem is in one or more of these somewhere.

The last and outside chance is a failing joint or coil in the starter motor windings - but they are more expensive to fix / replace than all the above -  so look at the cheap fix options first


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## Urick (Mar 26, 2009)

Just a quick follow-up; All external electrical connections are tight and corrosion free. I have changed the oil to a totally synthetic 5W-30 and have done nothing else. The first mowing session (btw it takes about 2 hrs to mow my area) after the oil change, the tractor started on the second try and cranked somewhat easier it seemed. Then Amazements of amazements! After sitting 2 weeks, the tractor cranked effortlessly and started on the first turn of the key! I don't know how it will act next week when I have to start to cut the grass but I am encouraged so far.


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