Has anyone installed this SlickStart magneto booster?

It is STC'd for M20Js. See attached files and demo vid on youtube : http://www.youtube.com/watch?v=eWhhdeVuclM

SJT still has starting issues (particularly when hot) and as much as I fear this may be covering symptoms rather than curing the root problem, it does look interesting...

SJT always cranks very slowly - yet the battery has been load checked as OK and is not old, the starter was overhauled, the voltage regulator replaced and calibrated as high as you can (14.2V), the earth circuit between the battery and starter was cleaned up - all should be OK but the engine always cranks like the battery is flat (and if you don't get it going, it soon will be!!) Suggestions?? Similar experiences?

Stuart,
Almost nothing to do with the magnetos will have any effect on how an engine cranks. How often do you fly the aircraft? If you are like me and have large "unused" periods the battery will self-discharge and not recover during short flights even with the VR set to 14.2 volts. What sort of charging currents do you see during flight by the way? Are you using an open cell or sealed battery? What brand? (The two common brands seem to have quite different field satisfaction levels by the way). How old is the battery?

The best way to check for unrecovered self discharge is to take the battery out of the aircraft, (this is permitted pilot maintenance by the way), take it home and charge it for several days with an automotive trickle charger. Then put it back in the aircraft and tell us how it cranks. If it cranks OK then but won't remain charged while sitting around you could try standby charging on the ground. If it is in a hangar get a plug-in trickle charger. If it is outdoors use a solar charger. I notice Ned Kelly uses solar standby charging so I installed that myself and my normally sluggish cranking suddenly got very brisk.

Skip

That is a very interesting video....I had not heard about this product but I think I will take a look at it while at OSH this year. Seems like a good device whether or not cranking is slow. Skip's points are spot on. I would only add that if you continue to have cranking problems after checking on battery issues you might try an expensive solution, namely install one of the new light weight starters such as Skytech. I did that years ago and was amazed at the improvement in starting!

Stuart,
I had the same problem with MZX. Had to have everything crossed, whenever I started her hot. If you missed the start you had a flat battery. Installed a new battery (sealed). No better.
I then installed a Skytec starter. Best thing I ever did. She will now almost fly on the starter. Fantastic for hot starts.

Wow - thanks for all the replies - this forum works seriously well.

Yes, I realise that mag problems and cranking speed are unrelated, but they do both contribute to the fundamental issue of the engine starting (or not).

In reply to questions posed:
The battery is a Gill 35S sealed battery. It is 19 months old (I think, maybe a month or 2 either way)
I have a BatteryMinder and put the battery on charge (which becomes a trickle charge after a while) for days at a time. Cranking speed doesn't change appreciably afterwards.
The battery is of course an electrochemical cell, and it has been cold lately - so output is unavoidably down of late due temperature.

The aircraft is currently flow 1-3 times per week.

For those of you who know Kev Lewis, the other (former) 1/2 owner of SJT, he has sold his share to Rowan Hill, a new AMPA member.

From what I'm hearing, a lightweight high speed starter needs to be on our shopping list! Does fitting one require an EO?

Regards

Stuart,

NWF got a new Concord Gell about the same time as SJT. For the last year she has been grazing in a nice warm hangar, given a run about once per month. She has been starting cold and hot pretty well (for a 1500hr engine she is doing very well, John Chesbrough really knew how to care for an engine). So what are the differences, they are both about age etc. NWF has spent a lot of her life in a hangar, I do not know about SJT. But the one cranking item that is important is not only the earthing but the very high current power cables. The starter motor relay can be a cause of problems if it has any contactor oxide buildup or if cable crimping has oxide buildup owing to atmospheric conditions, particularly if unhangared. To test this wiring I would use a Ductor low impedance device, the ohmic resistance has to be very low.

I have hand swung my prop several times, it has always been easy to start. I was once told that at least one magneto has an "over centre device" that acts like a trigger giving a high velocity passing of the magneto coil that, even at low rotational speeds, gives a nice fat spark. If you cannot hand start SJT maybe you have a different problem, I do not know how fine wire plugs react with these starting devices. A swing of the prop may bring light to bear on where the problem lies.

Geoff
NWF

I had the lightweight starter installed some years ago. It certainly cranks much better than the original. Even the lightweight starter will not crank well with a dead battery or with poor grounds, corroded connections or solenoid. I also had a Gill 35S sealed battery which died at about the same age yours is now. You will notice that Geoff has a Concorde battery.

It might be difficult to source equipment to measure the very low resistances in battery cables and connections but it is not hard to measure the voltage across the motor terminals when it is cranking. If it is normal look downstream (at the motor and its couplings) if it is low look upstream at the cables, connections and battery. You can be fooled here by shorted motor windings but this is a good starting point for diagnosis.

Skip

I too had a lightweight starter installed when I had a top overhaul a few years back and experienced the ame improvement others have.

My battery has just died - or so I thought - from ground running to trouble shoot an autopilot problem. Using my new BatteryMinder it was back to full charge in an hour. I had already ordered a Concorde sealed GSX as from my reading on the net this is supposed to be the bees knees. My LAME tried to talk me out of it as he said he would only sell a Gill sealed to the competition's clients and said Concorde would be the same. He wanted me to get a normal Gill flooded. Nah, I wanna try the Concorde to see how it lasts. The last Gill was just at the two year mark and has now been flattened twice. I shall report back as to how it all goes.

He had heard of the Slick thingo but not seen one.

With those Gill G35S's the S stands for S.....t. I used to install them but got sick of the warranty replacement and so opted for the Concorde sealed option. Since using Concorde I haven't had a complaint in fact I had A customer that rang us only yesterday to say that this is the first winter in 3 years that he hasn't had a starting issue. We replaced his G35S late last year with a Concorde RG35AXC. Most Concorde customers I have get over 3 years and some over 5 years from a battery.

The 'over centre' device referred to earlier is the 'Impulse coupling' and every 'dual mag' M20J has one. As the 'dual' mag has only one drive it impulses both mags for starting. Simply, the device has two pawls with springs that hold them out at cranking rpm or less. These pawls 'catch on two posts in the mag and hold the drive while the engine keeps winding up an internal spring in the coupling. After a set distance more rotation the pawls let go and the spring accelerates(impulses) the mag at a higher rpm to catch up to the engine again and thus create a higher energy spark at the right time. The clicking sound you hear when pulling an engine through by hand is the impulse letting go. At higher rpm the pawls are weighted so that they retract and don't catch on the posts.
Skip is on the money for a simple way of checking the voltage at the starter. If you have anything less than 10VDC once cranking then you definitely have too big a drop somewhere up stream or maybe not enough stream to begin with.

Hope this helps.

I am not an expert here so Hamish please clarify or comment. There has been no mention of how the ignition system is retarded for starting - I assume this is another job for the impluse couling. If the spark is not retarded for starting, the fuel burn will commence too far before TDC for the low RPM- will this make it harder for the starter motor to turn the engine or will it simply make the engine kick back? Won' t that also make the engine less inclined to start?

Andrew,
Yep that is also 'built in' to the function of the Impulse Coupling. The pawls are set to trip at the 'right' timing for a start ie retarded.

Cheers H