as per title. put two in it over the last fortnight. dip blows first, shortly followed by the main. 35w35w that only work when the bike is running. the first time it blew i didn't have a spare so quickly checked the voltage, i'm sure it showed 6v at the headlight plug (it's a 12v system) but bright when the bulb is replaced. odd. i will need to recheck on the rare occasion i can prize it off of him. anyhoo, the charging voltage seems fine. around 14v so i'm assuming the light circuit go through the regulator, which i'm starting to suspect is faulty. low voltage wouldn't blow bulbs tho would it? what am i missing here
Fin, first thing to check is the quality of the earth connection. I have had two similar instances, one with a GS550 blowing what were very expensive H4 bulbs and one with a Lancia blowing rear side and brake light bulbs almost weekly. On both occasions the issue was an intermittent earth continuity at a location I was unable to locate. In the case of the GS550 I was blowing dipped beam filaments every 2-4 weeks and on one occasion lost dip and main beam on a late night 20 mile ride home from work. Both problems were fixed by adding a supplementary earth wire from the bulb holder to a known good earth point, on the GS550 it was straight back to the battery negative terminal. Poor earths can cause significant thermal stress on the bulb filaments as the light effectively gets switched on and off at very high speed due to vibration affecting the continuity. You need to also check that the connections on both - and + paths are clean and tight all the way through the circuit. Good luck tracing this one as it could be a sod to bottom out and you will not necessarily see anything when you check for circuit continuity or resistance. Reg voltage around 14v would suggest there is not much wrong with it but you may want to check it across the rev range, expect it to vary between 13 and maybe 14.5v depending on the engine speed.
nice one. i did repair indicator wiring around the headstock two weeks ago. i wouldn't be surprised if it's in that area. cheers, never thought of an earth issue and may explain the 6v at the plug. Doh.
yeah, funnily enough I was trying to help a mate with her RSV4 yesterday with the opposite issue, sure enough it was a cooked stator as I suggested but it was just flattening the battery. I'd say in this case, more likely reg/rec which could be letting the voltages go over 15v at high revs, we had a 748 once that at 6k revs was throwing something like 18v at the battery... dread to think how a lithium battery would have dealt with that.
i guess i could just run a wire from the Bat- (after rechecking voltage) to the earth wire on the headlight plug as a quick fix before i use the hot line to my Aprillia dealer.
tonight i am going to fit a rec/reg to the lads bike. i noticed the other day that you can get battery voltage readings through the dash. showing 14.9 at tick over rising to 15.2 with higher revs. not mental high but seams a bit high compared to what i'm used to. since the headlight started blowing bulbs, he has noticed the temp gauge sitting higher and overheating. several times today as he has been using it during the day until the reg turned up. it's not loosing coolant, i'm not familiar with water pumps failing intermittently (some do if the impeller is pressed on to the shaft) so what i'm thinking (hoping) is that the possible over charging is messing with the sender/dash reading. anyone heard of this?
fin, yer such a dick. lad, yer such a knob. earths seem good, fit the reg, charging a lil lower so bulb wise we will need to wait and see but still over heating. check the water pump impellor all good. but no water in the housing. wtf? recheck expansion bottle and the level is still sitting on the minimum. bolt it all up and top up the coolant to the max and it just keeps taking more and more, not that much but considerably more than you would expect from min to max. start it up and guess what, it's no longer over heating. but does have a small drip from a hole behind the water pump which is easily sorted with a seal i ordered. ask the lad if he has seen anything unusual under his bike and he says aye, a puddle of red stuff under the engine every time he parks it up.
My lads RS4 50 only holds .9 litres of coolant. https://www.vespaforum.com/manuals/Aprilia/RS50/RS4-50/RS4 50 Workshop Manual.pdf
He's a lad and young. We all did stupid things when we were beginning back in the day. At 15, I repeatedly (like for at least an hour up and down the hill outside my home) bump started a Lambretta GP150 I bought for £5 trying to get it to start. It had no spark plug in it ffs.
aye, but with you that's kinda to be expected. where as i, have just proven that a lil knowledge can be dagerous.
i guess i wont know if any head/barrel damage has occured untill he can use it again. we will find out tomorow and over the comming days i guess. starts and sounds ok tho he did say the engine sounded different when overheating. i'm gona take a hit with this but all i need is another 4 months out of this one before he turns 17. unlike 50s, geared 125s are plentiful. during the day it's been scortchio for the last two weeks. but baltic first and last thing when he has been using it.
When I eventually started the GP150 I never knew I had to premix oil and promptly heat seized it not long after. The joys of youthful finding out the hard way.
aye, to think of the death traps i used to ride around on back in the day. in this part of the world you need a bit of reliabilty in yer life. the next one will be new. tho saying that, he has been eyeing up my coupe and reminding me of an aledged convo we had promissing him it when he passed his test. hmm, i do have a faint recolection of saying it. cant imagine i meant it tho.
or better still, when i pass mine in clasical english literature. and thats only after he has cleaned his room. chortle.
