P88 Dynamo/carbon?? Starting Issue

Hello all,

Checked the Battery (full), Ignition coil (sparks when shorted but no ignition - local mechanic's crazy idea). Fuses are all fine. When I push the ignition, there's only a small "tick" - and nothing happens. The mechanic said that it should be the carbon in the dynamo that's "been used up". Didn't trust him enough to open her up and let him investigate. Changed all 4 spark plugs 2 months ago and they should be still ok. Did ~150 kms 2 days ago without any issues.

Just got my bike a couple of months ago and everything else is fine with it - quite a clean bike. Don't really know the technical terms, if anyone could help me out here, would be awesome!

Can I get the dynamo carbon from any other bike or is that specific to the XJs?

Thanks!

 

take the cover off of the right side so you see the battery. to the left of the battery you should see a plastic/metal cylinder with two big wires and two small wires. one big wire goes to the + side of the battery the other goes to the starter.
put the bike in neutral.
with a coin or screwdriver gently connect those two big bolts for a instant. there will be lots of sparks and the starter should go. even with the key off.
if this works the starter is good and you need a starter solenoid, that's the thing that just made all the sparks.

 

"with a coin"

Sadist.

I still can't stop laughing. Please don't use a coin.

 

The carbon that the mechanic is speaking of are the commutator brushes. When he says dynamo he's probably talking about the starter motor.

Since the solenoid clicks, and the starter doesn't turn, it's worth checking the starter brushes.

 

With Fitz on the coin; use a screwdriver, but if you do use a coin video and post!

 

The bit that got me was "gently connect"... Whatever you use, connect it between the bolts quickly & firmly as you'll get less sparks that way. And +1 on z32800 if you use a coin please film it! :lol: (and have a bucket of cold water & tube of Savlon on standby!)

 

I'm pretty sure "dynamo" means generator or alternator, and he was referring to the alternator brushes.

Worn alternator brushes will cause a charging issue leading to a flat battery, but not prevent the bike from turning over.

You said the battery is "full" but is it fully charged? A flat battery will also give you a click at the solenoid and nothing else.

Shorting across the solenoid terminals will answer a lot of questions (battery charged enough to turn the starter, starter can turn the motor, etc...)

 

Hello folks,

Thanks for your response and suggestions!

@Polock: yeah, did that. The local mechanic used the screwdriver and there was a spark while shorting the two terminals of the starter solenoid. She didn't start.

@k-moe: got the starter motor out today and gave it to be checked. She's 26 years old and I doubt the starter motor was checked before I bought her. The carbon brushes might have worn out.

@bigfritz: had issues with the old battery as well, it used to die on me every other day even after fully charging it and riding at least 20 kms a day. So it might indicate that the charging issue existed beforehand. Gave her a new battery and had no problems before this issue. The battery is fully charged and only 2 months old, so I doubt that's the core of this problem. To rule the battery out, I checked the acid levels (around "Upper Level"), the voltage (12v) and current (~14Ah). I will get the starter motor back tomorrow and will let you guys know how it goes.


I told the local mechanic that he could use an un-insulated no. 10 wrench that was lying next to him, he just stared at me and insisted that I bring him a screwdriver with an insulated handle. No way he would have used a coin. As for me, when he said that there'd be sparks flying around, with a fully charged battery right by its side - I went to the other side of the bike and handed him the screwdriver. Will go on a tour again in a couple of weeks and I'd rather be cautious than be in the hospital having skin grafts.

 

i don't know what's so funny here but if your afraid to try it i suggest you put some fertiliser down your pants.
watch and learn

 

I don't get what anyone is worried about either. Low voltage, fairly low amperage (though high enough to cause big trouble if it jumps across your heart), and the coin is a much better path to ground than your body. Using a coin on a starter solenoid is safer than checking a 9v battery with your tounge.

 

As a former TV News liveshot producer dependent on 9-Volt Batteries for Wireless Mic's and portable intercom devices, ... the "Tongue-test" for 9V Battery freshness was S-O-P!!

 

@ Polock: thanks for the video, didn't spark that one! But I see that if done right, its quite safe, and without sparks with good grounding. Thank you again for showing it. Fertilizers, I'd love to see a video too. We have different senses of humor, senses of safeties, but we have the same love for our motorcycles. Let's leave it at that.

@K-moe & Rick: Once upon a time, I tried to solve my transistor/radio power supply problem. I was stupid enough to have the cable plugged live to mains (unknowingly) and was chewing the other end to take the sheath off for a new wire connection to screw onto the main plugs. I got all of the 240V on my tongue for a couple of seconds before my reaction threw the wires off. So, 9-12V jokes are amateurish.

You guy are so experienced with a wealth of knowledge amongst you. A newbie comes along in this forum to learn and you give them a dick measurement scale! You should be telling them to go slow knowledgeably and be safe while learning about their motorcycles. Telling them to go back to their manuals and/or where they could buy one! Accidents happen specially when it is least expected. Not all of us are pros here or have opened up a couple of XJs to be a bit bashful Riding/owning bikes (XJs in this forum) are a passion and they are willing to learn much more, if you're willing to help them out with useful advises. Lame shit advices/remarks, you can get everywhere else.



I think that was the original motive of this XJ forum!!



Yeah, the starter motor is good now, the rubber seal was leaking mobile into the carbon brushes which were destroyed. Changed the starter motor seal (towards the end to the engine joint) and the brushes, the bike starts fines now. Had an explosion once when I started her, probably backfire with smoke coming out of my right silencer (which the pro-mechanic said was "fine"), started her 5 times again without issues. She's running great once again, with good throttle response, and I hope this helps someone with similar issues down the road.

Like the experienced members say on here, I would echo that if you have the dough and the passion, when you buy an old bike (any bike), change all the old rubber seals, gaskets and boots of the old bike, and also make sure the carbs are running optimally. Body paint/add-ons and other bullshit are for already great running engines. If you don't have a good motor engine, forget about riding a motorbike. Rather stick to the old bicycle because you'll be pushing your motorbike down the slope to get it started anyways.

Thank you all once again for your advice and input!

Cheers,
Sam

 

Licking a SMALL 9Volt Battery isn't going to electrocute you.

As I mentioned, its Standard Operating Procedure for testing the health of the Batteries in Mic's, Intercoms and Small Linen Amps before doing a Live-shot.

If the Terminals "taste ... salty-tingling" ... you're good to go.

 

Exactly. I know this because my first career choice was to be an electrical engineer. I studied electrical theory (and practice; the part that most engineers forget about needing to learn) for three years, and worked as a maintenance technician for 6 years.

No bad advice was given in this thread. Rarely is bad advice given on this forum, and when that happens it gets corrected very quickly. Nor were any jokes made. I think the confusion comes from the usual difficulty of translating meanings from one language to another. Literal translations rarely convey the intended message accurately due to differences in word useage, and cultural meaning.

I'm very happy that your ride got fixed.

 

@ Rick and K-moe: yeah, "we are sinking" moment http://www.youtube.com/watch?v=guELpieYlFU

She's running great and rode her the entire day. I will post some pictures after my trip.

Cheers guys and thank you once more for your advice!

Sam

 

I think the only joke made was Polock's fertilizer bit, aimed at myself fitz & z32800 I guess since we were the ones who said don't use a coin.

Speaking of which, just to clarify I wasn't worried about electric shock (or even electrocution). More, the potential for a badly conducting old coin to get hot very close to fingers.

It might also be worth checking the alternator (generator/"dynamo") brushes too if the starter's were gone then the alternator's might be close to the wear limit too.
Either way the issues been cleared up & I'm glad be good to see those pics, bet your weather is better than here!