April 20, 2015 at 6:35 am #46385
So, I’ve been converting/fixing my used second TAG Engines, so I can use it as a practice engine. It was a pushbutton pre-09 engine. So far, I changed stator/rotor/coil to the newer ones, and got it to start with my keystart harness, using an external starter to start it. I then repaired the starter brushes, and they seem to be working too.
Now, I’m trying to start it with the key and it won’t start. The battery is charged, and I have tried multiple batteries too.
On trying to start, I either get a clink, a pee-ouww (like an old western bullet shot), or a single crank of the engine (about 20% of the time). If it would crank more, I think it would start. I checked it again, and don’t see how I could misinstall it since the 3 bolts to the casing are tight, and it must be pulled forward enough as a result. Unless it needs to be twisted to mesh properly.
The starter and my brush repair seems to be working and holding up. With the key on, it whirrs away.
I am wondering a) if the teeth in the starter, or b) the teeth in the ring on the crank are not meshing properly or are worn out.
Does the starter ring wear out? How can I inspect it? Do I need to pull the clutch?
Can it be replaced easily? Any tricks?
I have the engine mounted on the kart, and don’t want to remove it if possible, to do any of the work – I very painstakingly got the chain aligned.
Thanks in advance for thoughts and advice. Samir.
April 20, 2015 at 7:56 am #46402
If you’re sure the motor is not stuck, pull the clutch drum and inspect the ring gear for damaged teeth. Also pull the cover off the bendix and check it out. To remove the clutch drum without loosening the motor, unbolt the axle gear from it’s carrier and take the chain off. The ring gear can get bent. Turn the motor over by hand to see if the gear is bent.
If your engine never needs repair and you never have to change axle gears, your perfectly aligned engine will never have to removed. Good luck with that. :)
Still sounds like a week battery. Get a heavy gauge wire and put a connecter on one end that matches the one that comes off the starter motor. Take the other end of the wire and touch it to the positive terminal of the battery. Should crank. Did you repair the starter motor brushes or replace them? You also could have a dead spot in the starter motor.
LAD Specialties customer / tony kart / rotax / kt100
April 20, 2015 at 9:14 am #46410
I removed the sprocket, Bendix cover and clutch drum – starter gear looks straight, no broken teeth either.
I checked for spark – its there.
Fuel is flowing and there is suction from the carb.
Battery is good.
I had repaired the starter brushes, did not replace them.
I played around with trying to start w/ a little throttle. That seems to have helped. I got a few incidents of a single pop and flame from the header.
Once the motor actually ran for 3-4 pops, and died before I could catch it and rev the engine.
I tried the direct wire to starter. On this engine, same thing – clang or richochet or one pop.
I see what you mean – engine should keep cranking – I tried the direct wire to starter on my other engine (off the kart), and it kept turning the engine over.
So the problem lies in starter, or bendix. Could it also be a carb issue?
April 20, 2015 at 9:43 am #46412
Next, I think I’ll have to remover the starter again, and maybe rebuild it with fresh brushes.
Will fresh brushes take care of any dead spots in starter? The brushes I repaired were curved from wear but had a fair amount of depth left. Maybe the spring on 1 side did not get fitted properly?
How can I test the armature to make sure it is ok?
April 20, 2015 at 9:48 pm #46457
Been reading old posts – and they are pointing to either a bad ground, or a bad bendix.
Will tackle these tomorrow.
Anyone with advice on how to most easily remove the bendix? And how does one clean and test one?
April 21, 2015 at 6:49 pm #46535
So, I took apart the starter again, and found the problem – the magnet ring inside the starter had broken and fallen apart, and was rubbing against the coils of the starter armature, causing friction, and thus reducing the power of the motor, which now was not strong enough to get the bendix spinning fast enough.
Anyone seen this before? Can a replacment magnet ring be found, or is this starter toast?
April 27, 2015 at 3:33 am #46991
This is still not working – tried 2 new starters, they engage briefly, but no crank. So it must be the bendix. Grounds good, battery good, harness, etc, works just fine on my other engine.
Do these wear out, or just get dirty and clog? I sprayed it out with brake fluid followed by a teflon spray. Should I soak it in gasline?
Or do I need a new bendix?
April 27, 2015 at 5:45 am #47000
When you say it still won’t crank, what exactly does it do now? If the starter, battery and harness are all good the starter should spin when you try to start it. The bendix has a gear on it that engages the ring gear on the clutch when it is spun by the starter, and it has a small spring in the end that pushes that gear back. That is basically all that is in them, a pair of gears and a spring. See if the teeth are good on both ends of it and see if the spring still is intact and the end moves in an out freely.
April 27, 2015 at 5:57 am #47003
I found this on youtube. This is not my engine or video, but this is the same thing as what is happening on my engine. Starter spins, might throw a pop, might push the piston bit, but wont generate enough power to crank over the engine before the bendix retracts. Even with direct 12V to the starter.
On my other one, direct 12V to starter will make it keep turning over the piston and keep cranking.
Tried multiple starters.
So got to be the bendix.
So either something is the wrong size somewhere, its not aligned properly, or there is friction preventing the bendix from spinning up enough, and it retracts prematurely.
The bendix seems simple enough comceptually, so I’m loathe to just replace it. How can I take it apart? Maybe the spring is not the right one, too weak or too strong?
Anyone with a spare?
You must be logged in to reply to this topic.