JeanJeannie60
New Member
Can anyone help with a diagram how to rewire starter motor. Have new starter motor in place..but dont know where electric connetors go?. Thanx
Re 2.2 BMC diesel engine
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bristoljim
Well-Known Member
Large negative to engine block - large positive from battery to large free terminal on the solenoid ( round lump on the side of starter)
small positive from starter button /switch to small free terminal on solenoid usualy spade type terminal
rather basic but hope it helps
Jim
small positive from starter button /switch to small free terminal on solenoid usualy spade type terminal
rather basic but hope it helps
Jim
johnlilley
Well-Known Member
Just make sure it is not positive earth though, the older vessels were using a positive earth system, Might get the odd spark or two if wrong way round !!!
JeanJeannie60
New Member
Thankyou for that...I also have a new automatic bilge pump to fit. It has 2 grey wires coming from it. The supplier says that it doesnt matter which way the wires are attached to the battery doesnt sound quite right to me...
JeanJeannie60
New Member
Thankyou for that....
johnlilley
Well-Known Member
IIf both wires are the same colour then I would think he is right. I It doesn't matter. Just make sure they are identical, some have a thin white or black line on the base grey wire
JeanJeannie60
New Member
Thankyou. I still dont understand why it doesnt matter though...As one is going to a live terminal and the other a negative...
RobinBirch
Well-Known Member
But you do need to make sure that the bilge pump is connected so that it pumps out. Test it when you have connected it. If it does not work as it should swap the connections over and test again.
JeanJeannie60
New Member
Will give it ago thankyou.
oldmanofthehills
Well-Known Member
If identical on bilge pump then it means either a series wound motor with field coil and rotating coil, so motor always goes same way as reverse of field coil is matched by reverse of rotating coil, however thats more usual on larger motors such as your vacuum cleaner so more probably a diode bridge etc in circuit so that motor and controls always see the same polarity whatever you feed in.
Your starter motor however might or might not be different. It wont harm it to spin the wrong way, but if not pre-engaged it simply wont turn engine if going the wrong way, and if it is pre-engaged it will turn engine the wrong way so wont start. Should harm nothing however unlike my mates old Isetta bubble car which had engine start in reverse in order to reverse and he got it wrong and accelerated swiftly from the garage but actually back through his fathers workbench
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JeanJeannie60
New Member
Lets hope we dont reverse into anybody,s boat......thankyou.
oldmanofthehills
Well-Known Member
Fortunately almost all engines wont run in reverse, unlike the odd Issetta bubble car. I did once go unexpectedly backwards on launching with new engine when the installer had failed to note that the boat had a left hand prop but the engine, like most, needed a right hand prop. I didn't hit the launch facilities but my nerves sure needed calming.
JeanJeannie60
New Member
When I first had the boat it was controlled by a cast iron lever coming up from the floor (those were the days) And I couldnt get it to go in reverse! So it was very tricky trying to moor up and stop!...
rotrax
Well-Known Member
In the words of the old joke, that Focker was a Messershmitt!
The Isetta had a single cylinder four stroke engine, motorcycle derived, IIRC no reverse gear.
The three wheel Messershmitt had a 250cc two stroke engine, reverse capability achieved by a second set of points changing the timing to allow the engine to run in reverse.
As it would reverse at full throttle and the castor action of the front wheels was great, steering backwards was tricky!
oldharry
Well-Known Member
Because it's a centrifugal pump and it doesn't matter which way the impeller rotates. Many smaller pumps are built this way. The vanes create suction as they rotate because the perimeter is moving faster than the vanes near the axle, so the direction of rotation is irrelevant. Common in bilge pumps because there's no valves or seals to clog up and unless a non return valve is fitted it's self cleaning as the water runs back when it stops. The ànnoying bit is that they can never clear all the water for the same reason. DC motors will run just as well either way.
DownWest
Well-Known Member
Agree about the Messerschmit (sp?) or a Heinkel, but the Isetta had a four speed and reverse g/box. I drove a couple in the day.
oldharry
Well-Known Member
You couldnt (can not?) drive a three wheeler that has reverse gear on a Bike licence, and they produced one to accomodate that law. I was going to buy one when I still only had a Bike licence, but it proved too far gone. Gave rise to the joke that all the old Isettas are stuck in garages with the owners still inside them because having driven in they couldnt open the door to get out.
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There was a small <10 hp two stroke engine that didn't have a reverse gearbox. It had to be stopped , and restarted in reverse to go backwards or, more importantly, act as a brake. Someone will remember the name!
I believe the Isetta had 2 wheels at the back making it a 4 wheeler.
I believe the Isetta had 2 wheels at the back making it a 4 wheeler.
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DownWest
Well-Known Member
Isetta three wheels in UK, four in Germany, but still narrow track at the rear as different laws.
Back to BMC..
Back to BMC..
rotrax
Well-Known Member
Sachs 250 single cylinder two stroke. IIRC that was the one fitted to the Messerschmitt. Crankshaft mounted dynostart wired to rotate the engine for starting in either direction, depending what way you wanted it to go. They could go through the gearbox in reverse, after a certain speed, not very high, castor action took over and instant disaster!
I had the privilege of racing a good 1934 Scott 650cc two stroke twin many years ago. While waiting at the pit gate onto the track with the engine running, it sort of hiccuped and sounded a little different. When the pit gate opened I engaged bottom gear-a brave gear, 70MPH plus-released the clutch, and ran the gate marshal over as the bike went backwards.
It had changed from rotating the right way, to the opposite way when it hiccuped. Got a mention in the race report in MCN IIRC.