Siromer 204s starting problem

[paulmowers]

Hi people!

This is a customers machine which has got me well and truly stumped, so I'll give you a rundown of proceedings.
So customer calls and says it wont start (from past experience of this tractor i'm thinking air leak in fuel system or a blocked filter), when I get there pre heaters work but crank position gives a chattering solenoid with no rotation at all, battery voltage dropping to about 7v during cranking.
Wasn't exactly 100% sure the battery had failed as I would have expected voltage to drop to 5v or lower during cranking, but what else could it be? Especially as the customer said it had been cranking slower and slower over a number of weeks, so advised him to get a replacement battery.

He did, and it still chattered when trying to start! mmmmmm.......... I go back and remove the starter for testing in the workshop, so bench test, solenoid works fine, solid movement and good switching, however the motor current draw was very high, almost welding the test lead to the terminal and the rotation was about half speed or less of the speed I would have expected, there was no instant oomph to the spin it was very high power draw and a slow spin up to its low speed.
Dismantled it and out came the smoke, brushes worn to over half length and commutator badly burnt on 1/2 of its segments.
Burnt out starter - right?

Got a new starter for it, fitted it today, it cranks slowly frequently stopping and spinning freely like its become disconnected, this one is drawing excessive power too as the supply lead started to smoke after a short time, am thinking if I'm not careful I could easily burn out another starter on this!
I am now thinking there is something major wrong with this engine, but not having much experience with these engines, (yangdong y385? I think) I don't know the most likely place to look for tightness, I mean it has been standing outside for a good couple of weeks since it broke down, is it possible rain has got down the exhaust and one cylinder has water in causing the engine to hydraulic?

Could the hydraulic pump cause these symptoms?

I know the problem, at least I think i do, the engine must be exceptionally hard to turn causing the starter to draw excessive power and burn itself out, why is the question please, anyone?

Thanks Paul

 

[paulmowers]

No ideas then, ok, Siromer have no idea either!

Here's a maybe for your thoughts, clutch release bearing? You have to hold the clutch down when trying to start so maybe the bearing has either seized or even worn through the release fingers if it has them, only thing is when i had a car do this many years ago it wouldn't crank with clutch down but it also almost stalled when pressing the clutch to select gear or pull away, so not 100% sure on this.
Does anyone know where the clutch inhibitor wiring goes to the switch so i can bypass it and try starting with clutch released?

Thanks paul

 

[paulmowers]

Well, clutch inhibitor is right under the clutch pedal arm so dead simple to bypass, oh and engine still cranks real slow with a slow grinding noise.
Removed starter from engine, connected up wiring and tried again, pinion moves out real quick and motor spins fast as usual when solenoid energised, so clutch release bearing ok and new starter motor ok.
The edge of the ring gear teeth were all a bit knocked about so spent some time with a small grinder taking the burrs off and re shaping the lead in chamfer on each one.
While doing that I turned the engine round with the aid of a large screwdriver through the starter hole,there were no tight spots during the rotation.

So starter back in and try it again.

First attempt on a heated start and it cranked normally, subsequent attempts were hit and miss, sometimes it cranked normally sometimes slow with the grinding noise.
Out of sheer frustration I turned the key to the left, unheated start and it wound over normally and started up!
So stopped and started it a few times without heat and without issues.

Now I have to try to work out how and why there should be this difference between starting with heat or without.

anyone had any experience with these?


Thanks Paul..

 

[pycoed]

Glow plug (or plugs) shorted to earth, drawing excessive current when plugs & starter are engaged? Also check cables/relay in glow plug circuit.

 

[jimmysisson]

Checked both battery cables for good contact and corrosion?
Jim

 

[paulmowers]

Thanks for the suggestions,
The glow plug being shorted did sound likely although I would have thought it would have manifested melted wiring or a blown fuse to be honest, but thanks for the suggestion. However the customer now reports the starter is now either missing engagement or jumping out at every 3 or 4 revolutions.
As previously mentioned I have cleaned up the lead ins on the flywheel, that is assuming there are supposed be be lead in chamfers of the flywheel teeth and they are not supposed to be square cut. If they are meant to be square cut then this is the issue especially as there will be less power during a heated start to hold the starter pinion in place.
It has had a new battery, and all battery connections have been removed, cleaned, greased and re tightened, the earth connection to chassis has been supplemented with an extra link straight to the engine.
Also he reports that after getting it started and while grass cutting he has lost all hydraulics! No implement lift and no power steering.

I am getting a bit miffed with this tractor - The two issues can't be connected, can they?
It had a new hydraulic pump on it around this time last year as the original leaked oil like a sieve!

Thanks again Paul.

 

[scottie9]

possibly the hyd pump has been dead heading, thus loading the engine at startup, and this has now blown the pump. this deadheading would also cause the starter to overload and burn up

 

[paulmowers]

Thanks for the suggestion,

I'm not entirely familiar with the term deadheading, I assume it means the output of the pump has nowhere to go and it overpressures? Is this likely with no external attatchments and only its onboard 3pt hitch connected, I know the q/r coupling self seal ball can play up behind the dash but they were all checked before fitting the new pump last year as the very last thing i wanted was to screw a new pump as soon as fitted due to those couplings.
Wouldn't it be really sluggish to start and run if this was the case?
Its just that when it runs, it runs normally, the same as it always has.

The biggest issue with this tractor is that it is regularly costing its owner a small fortune and I cannot keep throwing new bits at it until a cure is found, its already costing £200 for the starter.

My personal thought on it is scrap it for bits and buy an old ferguson vineyard / orchard tractor, they run for years without any problems!

Thanks paul

 

[DLTTrekkers]

Mybe your ext hyrauliclever is in detend and pump the oil (deadend) ....no pipes fitted at the back ?

 

[paulmowers]

Well update on the tractor, tonight the owner was going to drive it to my workshop so i could work on it more easily and often as time allowed, it wouldn't start, did crank but kept disengaging and spinning free, then would resort to a slow churning cranking, not quite grinding but not sounding at all right.
Some times it would just spin free.

Ive been looking past this - its a pre engaged starter!! HOW can a pre engaged starter which by definition HAS to engage before cranking spin free or disengage from the flywheel while cranking?

And its a new overpriced badly made starter from siromer.

The old starter which burnt out never behaved like this

The hydraulic issue I am fairly sure is nothing more sinister than low oil level as the owner had experienced lumpy lifting, but until the starting problem is addressed there seems little urgency in worrying about the hydraulics.