dshwasher Posted January 28, 2023 Share Posted January 28, 2023 Hi, I bought a little 2010 Aprilia RS 50 back in July and since then have been working to get it started up. To begin with, my issue is that the bike turns over but does not start, but will start when jumped. So far the work done on it has been (multiple) new batteries, new CDI, new top end and a new starter motor. Once jumped, if the bike is turned off it will not start off the starter: it will have to be jumped again. I’ve done some more reading today and every forum keeps leading me back to the battery. I did some research on battery codes and have found that the battery currently in my bike ends with “BS” while the ones that are apparently suitable end with just “B”. Am I correct to think this is the code for the terminals? Does it make a difference? Thanks Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted January 29, 2023 Share Posted January 29, 2023 Hello. Don't know about the battery code thing but I'd be checking with a voltmeter that you are getting 12v where it needs to be when the engine is cranking. Check for good earths and bad connections. Are the cranks seals ok? If they are tired , it can cause starting and running issues. Quote Link to comment Share on other sites More sharing options...
Mississippi Bullfrog Posted January 29, 2023 Share Posted January 29, 2023 By jump start do you mean it will start using jump leads or do you mean bump starting? If you are using jump leads where are you connecting them to? You can use a jump lead to make a temporary secondary earth from the battery to the frame. Always worth trying if you suspect a dodgy earth connection. 1 Quote Link to comment Share on other sites More sharing options...
dshwasher Posted January 30, 2023 Author Share Posted January 30, 2023 Hello. Noted. I will check with a voltmeter and check on the crank seals. I mean by bump starting it. Could you please explain what you mean by “good earths”? I’ll be getting a new battery later today with the right code and see if it makes a difference. Thanks guys Quote Link to comment Share on other sites More sharing options...
dshwasher Posted January 30, 2023 Author Share Posted January 30, 2023 Did some reading on checking for good earths. Am I right to think it’s keeping the positive rod of the multimeter on the positive terminal on the battery and putting the negative rod somewhere on the frame/a bolt? Quote Link to comment Share on other sites More sharing options...
Tiggie Posted January 30, 2023 Share Posted January 30, 2023 That's right. Always worth checking the battery has over 12v first and giving the earth points a good clean up first too Quote Link to comment Share on other sites More sharing options...
dshwasher Posted January 30, 2023 Author Share Posted January 30, 2023 Got it. I’ll be getting a new battery later today (as the old one is completely knackered) and trying all suggestions. Thank you 1 Quote Link to comment Share on other sites More sharing options...
Fozzie Posted January 31, 2023 Share Posted January 31, 2023 Your starter solenoid working? It's a dinky little thing, so wouldn't surprise me if it burnt out. Quote Link to comment Share on other sites More sharing options...
dshwasher Posted January 31, 2023 Author Share Posted January 31, 2023 It seems to be working. It is a new starter and does seem to be spinning fast enough. 1 Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 1, 2023 Author Share Posted February 1, 2023 Hi, I’ve checked and the battery has over 12V. Checked the earth points too and they all are okay… havent had a look at the crank seals yet. When I turn over the engine on both the battery and earth points I get just over 10V (which is apparently normal according to my dad). Quote Link to comment Share on other sites More sharing options...
Grumpy Old Git Posted February 1, 2023 Share Posted February 1, 2023 25 minutes ago, dshwasher said: Hi, I’ve checked and the battery has over 12V. Checked the earth points too and they all are okay… havent had a look at the crank seals yet. When I turn over the engine on both the battery and earth points I get just over 10V (which is apparently normal according to my dad). That seems a bit low to me - I would have expected at least 11.5V on load. Your battery (ignition off) should be around 12.5V (or higher). If it is dropping to 10V when you try and start the bike, then I would suspect either a high resistance connection (bad earth) or the battery is not up to the job and, seeing as you have a new battery, I would look at the connections. It could be any one of a number of earth points: Battery to frame Starter motor to frame Ignition circuit (solenoid) to frame Starter motor to frame As the bike runs OK once 'bumped', the ignition (coil / spark plug / etc.) would appear to be OK and I would look at the wiring (connections and earth points) around the starter motor and solenoid. 1 1 Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 1, 2023 Author Share Posted February 1, 2023 I’ve used my multimeter to check the resistance between what you have mentioned. Please correct me if my method is incorrect or I haven’t understood something the right way. I am a bit of a bike-noob I’ve set my multimeter to ohms and here are the results: Battery to Frame- 0.5 Starter Motor to Frame- 0.7 I don’t understand what you mean by the ignition circuit (solenoid). Where can I locate this? I did a voltage drop test by putting the positive terminal of multimeter on my battery and the negative terminal on my starter motor (input terminal). I start with 12.26V. Once cranking I get a drop to 0.5V. Apparently this is too high and should be about 0.25V or below. It could be the solenoid instead of the starter motor input terminal but I do not know how to test this on my kind of motor. It is a lot smaller than the ones I have seen. I’ve attached an image of it. Here is the link of the website i’ve been using: https://www.fwi.co.uk/machinery/solving-your-starter-motor-woes I appreciate all the help Quote Link to comment Share on other sites More sharing options...
billy sugger Posted February 1, 2023 Share Posted February 1, 2023 Ignition wiring takes a lot of current, so a starter solenoid is fitted inline, and when you switch on the ignition a small voltage is supplied to a set of contacts that energise a electro magnet in the solenoid and this closes the circuit to the starter motor. If the starter motor brushes are worn out or the windings are dirty, or the solenoid is dirty it will take more cranking amps to fire it up. The live lead from the battery should go to the solenoid, so try tracing that leads' path 1 Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 1, 2023 Author Share Posted February 1, 2023 I’ll take a look tomorrow. Thanks Quote Link to comment Share on other sites More sharing options...
Grumpy Old Git Posted February 1, 2023 Share Posted February 1, 2023 As your starter motor is bolted directly metal to metal, the resistance to frame reading should be less than 0.7 ohms! If you look at this logically, the total resistance that you have measured between you starter motor casing and the battery earth terminal is (0.5 + 0.7) 1.2 ohms. It should be less than 0.1 ohms! Your Solenoid is here: I would also disconnect, clean, reconnect the thick lead from the solenoid to the starter motor to remove any additional resistance there. Have you unbolted the frame earth point from the battery lead, cleaned it up and reconnected it - If not, you need to do so. One way to check your connectivity is to connect a jump lead from your battery earth direct to the body of your starter motor (you will need to hold it firmly against the metal casing) and try and start the bike - If it starts, then it must be an earth problem. if it does not start, then I would suspect the solenoid to starter connection. NB. Don't try this is there is any fuel drips near the starter! 1 Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 1, 2023 Author Share Posted February 1, 2023 I’ve just searched up the solenoid in my bike and realised it looks like the image i’ve attached. I’ve come across it multiple times not realising it’s the solenoid I will clean up the lead connecting. I actually have tried the jump lead technique before. The bike does not start: so I guess it is most likely a solenoid to starter connection issue. I’ll take a look tomorrow. Thanks! Quote Link to comment Share on other sites More sharing options...
Grumpy Old Git Posted February 1, 2023 Share Posted February 1, 2023 That does not look like any solenoid I've seen before however - It does have a 30Amp rating! Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 1, 2023 Author Share Posted February 1, 2023 Haha yes. No wonder I struggled identifying it Quote Link to comment Share on other sites More sharing options...
fredc Posted February 1, 2023 Share Posted February 1, 2023 it should have heavy duty bolt on connections similar to this 1 Quote Link to comment Share on other sites More sharing options...
JRH Posted February 2, 2023 Share Posted February 2, 2023 16 hours ago, dshwasher said: I’ve just searched up the solenoid in my bike and realised it looks like the image i’ve attached. I’ve come across it multiple times not realising it’s the solenoid I will clean up the lead connecting. I actually have tried the jump lead technique before. The bike does not start: so I guess it is most likely a solenoid to starter connection issue. I’ll take a look tomorrow. Thanks! That looks like a heavy duty relay not a starter solenoid. Quote Link to comment Share on other sites More sharing options...
billy sugger Posted February 2, 2023 Share Posted February 2, 2023 That is indeed a heavy duty relay. Has someone switched that for the correct part Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 2, 2023 Author Share Posted February 2, 2023 I’ll need to have a look at the bike (it’s not with me at the moment) and get back to you all. Thanks Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 3, 2023 Author Share Posted February 3, 2023 Had a look at the bike and can’t find anything that looks like a starter solenoid. I’ve attached the electrical system that was shown in the manual if it’s of any help. Last image being listed under “Battery recharge and starting”. I’ll be here looking to see if I missed anything Quote Link to comment Share on other sites More sharing options...
billy sugger Posted February 3, 2023 Share Posted February 3, 2023 I was curious, so have googled "starter solenoid" for your bike and it did indeed come up as the relay in your pics. The only other thing I can think of is a knackered sprag clutch putting too much load on the battery to turn the starter over Quote Link to comment Share on other sites More sharing options...
dshwasher Posted February 3, 2023 Author Share Posted February 3, 2023 I’ll do some looking into it. Thank you Quote Link to comment Share on other sites More sharing options...
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