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What speed should starter crank motor at. 225 Ficht

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baddog1016

Regular Contributor
I have been trying to diagnose a no spark issue with my 225 Ficht. I replaced the CPS because of bad ohm readin and I took the starter apart and it appeared to be in good shape. I cleaned and lubricated the starter and put it back on the engine but do no avail. By taking a slow motion video I determined my starter is cranking the engine at about 270 rpm, hence no spark. The voltage at the engine is nearly same as the voltage at the batteries, 12.77 V vs. 12.84V. Cranking voltage at the engine drops to 10.7 or so which from an automotive background doesn't seem terrible to me. I'm ready to replace the starter but am curious at what speed the starter should crank the engine assuming everything is in normal order. I have no reason to think there is a mechanical issue with the engine, when it last ran (September 24) it ran great and there is no significant voltage drop between the batteries and the engine
 
Before I replaced the CPS I had a no sync error. It did start once after I replaced the CPS but haven't checked again. I'm convinced I either have a bad connection someplace but the 270rpm is so close to the 300 rpm I have read that is necessary I wonder if when the stars are aligned either the 270 is good enough or the 270rpm might be enough to get it going. I also had an issue with my tach and wonder if the tach isn't taking the tach signal from the EMM so it doesn't start but it doesn't even try in the first ten seconds when the fuek pump is running. I will try with the software tomorrow.
 
I checked today with the software, no CPS sync happening. Cranking voltage at starter was only 7.84 volts (I checked both sides of solenoid) but 12.77 volts at battery side of solenoid not cranking. Group 31 lead acid battery and group 29 AGM both in the circuit when testing was done. AGM is a little over two years old and the other a year and a half. Both will hold charge. I have no reason to think there is anything mechanically wrong with the motor, compression is 105-115 psi and there are no unusual noises from it, cranking or last time it ran. I did but a starter from Amazon that was supposed to be a Sierra starter but it's not and the lower bracket is wrong so I am sending it back. Regardless, 300 RPM seems like an awfully fast cranking speed, because of the gearing it seems like the starter motor would have to spin at 4,000-5,000 rpm to get the flywheel at 300? I did double check my math, I get 8 revolutions of the flywheel in 5 seconds, which is 96rpm. I will get an OEM starter from the dealer but I'm open to any and all suggestions. Oh yeah, if I do the cold test with the software I do have spark.
 
Having thought about my issues I'm inclined to think there is an issue with the sweges in the wires between the batteries and the engine. There is heat shrink over them so Ihaven't looked at them closely. How common is this type of problem?
 
If a problem exists with the battery cables (it happens) such as internal corrosion... the cable will get very hot within a very short time of engine cranking. To test, just grab the cables in various areas... it'll let you know if a bad spot exists very quickly.

The cranking speed of 300 rpm needed to have the stator energize the powerpack is correct.

Easy test if the flywheel is engineered to accept a pull rope for starting.... Remove "all" of the spark plugs. Have a spark tester hooked up whereas a Air Gap can be set, with the gap set at 7/16". Have someone observe the gaps for spark while you (or someone) pulls the engine over sharply with the pull rope,

I know it's difficult to believe but, for the 2 or 3 times that engine rotates via the pull rope method... it's turning over a good deal more than 300rpms.

I'm not familiar with the Ficht engine itself... BUT... if there's a black/yellow wire attached to a raised "M" terminal of the ignition switch... remove it temporarily. If you have spark with it removed and no spark with it connected... replace the ignition switch.
 
Thanks for the info. Good point about the cables getting hot, easy to check. Rope on the flywheel isn't an option on this engine.
 
I hadn't read about a power pack on the engine but imagined it had to do with crank speed needed to get 40 volts out of the alternator. I will report my findings, I am going to fix this.
 
This is from the shop manual, it Needs the voltage to fire the injectors:

On 200-250 hp motors, the 40-volt system should show at least 20 volts when cranking, more than 24 volts and steady with the motor running at idle, and more the 39 volts when running above 1500 rpm. 20 volts cranking

No spark is my basic issue at this point so above isn't my problem.

 
Yes its a 3 phase stator and a 40 volt volt system...EMM has regulator in it . See what voltage drop is on system when cranking with software connected,its in the display.
 
It will be a couple of days before I do that but I know the cranking voltage was 7.84V down from 12.77. That's what made me question the battery cables.
I appreciate everyone's ideas, all good stuff to think about.
 
not cranking 11.21.19.jpgCranking data 11.21.19.jpgI'm attaching two snapshots, one with engine not cranking and the other with engine cranking. I also measured current at solenoid when engine cranking and found it to be 250 A but I don't have 100% confidence in my current clamp and I'm not sure what information this gives me. I think i remember that high resistance in the wires would make this current reading low and 250 A actually sounds high to me for the starter cranking. I could only check the wires at the engine for heat while cranking and they remained normal temps.
 
View attachment 22298View attachment 22299I'm attaching two snapshots, one with engine not cranking and the other with engine cranking. I also measured current at solenoid when engine cranking and found it to be 250 A but I don't have 100% confidence in my current clamp and I'm not sure what information this gives me. I think i remember that high resistance in the wires would make this current reading low and 250 A actually sounds high to me for the starter cranking. I could only check the wires at the engine for heat while cranking and they remained normal temps. I see that the engine is spinning fast enough to make nearly 20V for injectors.
 
Either the starter is bad,solenoid has high resistance internally,battery has low CCA output or gearcase is shot and dragging speed down or bad cables.
 
Thanks. This is really a tough one. All of my Ficht experience is with this motor but there pretty much isn'y anything you can do to an automobile engine that I haven't done.
I tried a different starter with no change. Group 31 battery is fully charged and hydrometer says all cells are good. I resealed gear case in the spring with no issues. Input shaft turned freely in neutral and there was no sign of water in it when boat was pulled. I think at this point I'm going to pull the spark plugs and see what crank speed is but I'm probably going to bite the bullet and bring the powerhead indoors for the winter. My thought is that if the current draw is accurate the starter is against a lot of resistance cranking the engine. I have no experience with roller bearing cranks and imagine if there was an issue I would hear it but I'm starting to think maybe not. Maybe a piston issue inset of the compression being okay?
 
I think I found it! I was tracing the battery cables to engine and found this. In hindsight I guess I should have known there had to be something like this. My power boat experience is limited to this one but I'm learning.
 

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