Yamaha 1981 LB50 PH Chappy resurrection

[twosmoke]

Hi 67, no, I have not checked the voltage of the battery, its only a month & a half old! could the rectifier be allowing 2 much voltage 2 pass?-------twosmoke

 

[my67xr]

The rectifier only convert's the AC power from the stator to DC so it can charge the battery.
The Chappy's don't use a voltage regulator, but if you fitted one that would solve the bulb blowing problem's
If you bulb's are blowing then your battery might already be fried too ?

 

[twosmoke]

Hi 67, nah, I don't think the battery is done, but 2 be sure, I'll see if I can check it. I put the 12V taillite bulb & the 15W headlite bulb in (not the 35W I jus got, jus 2 see how long it lasts) & it works, but wont know 4 how long till I get it rippin down the st! but its bright enuf 2 see tho. & how would I install a regulator neway? electrical is not my forte, Im jus good @ burnin **** out! hahaha, thanks 67,-------twosmoke

 

[twosmoke]

Hi67, another snag, I got the flasher connected, but when I put on the indicator switch, all the lites dim on & off like they're flashing? the headlite blew out again, so I checked the battery voltage, & it read 0 volts, would keepin the ignition key on all the time drain the battery? is there a way 2 recharge it? the battery is less than 3 mnths old! thanks 67-------twosmoke

 

[twosmoke]

Hi again 67, another thing, I jus checked the electrolyte level in that dead battery, & ya know what? those f@#$%n morons @ the shop where I got it, only filled up the middle cell! what should I do? add distilled water 2 the level? will it form an electrolyte if I do? can it b chged if I do that? or should I bring it back 2 the shop & get another 1? that's y the bulbs blew out, I'm pissed!-------twosmoke

 

[my67xr]

Over here when we buy a new battery it come's with a bottle of electrolyte, we then have to fill it before fitting it.
there is normally sufficient charge there to start and or run your bike.

If they have been sitting full before being sold you can charge them up prior to using them.
But the motorcycle lead acid battery's should only be charged with a low amperage charger, around 800Ma or a bit smaller for a couple of hour's (6V too in your case)
The instruction's that come with it usually have all the exact detail's too.


I don't think you be able to charge it after adding just distilled water but hen again it may come good, maybe specific battery electrolyte?


The battery also act's as a load on the charge/lighting system, and help's to soak up some of the power that's not being used.
A new fully charged battery may help the bulb blowing problem.



Iirc, it was either me on my youngest son left the ignition turned to the on position on our Chappy, and the battery died not long after that.

 

[twosmoke]

Thanks 67, well, I guess I screwed up twice, I shoulda checked the levels when I got it & I shoulda shut off the ignition switch when shuttin it down, but there's no xcuse 4 fillin up jus 1 cell & sellin it. I'm goin back there 2moro & either havin em add the missing electrolyte & chargin it fully or they're gonna replace it w/a fully filled, fully charged 1! its lil sh%t like this that really slows me down! can you xplain y the headlite & taillite dims every time the blinkers flash? I have no idea y this is happening, I'm sure everything is wired correct. oh yeah, having that dead battery also blew out my new 25W headlight bulb, but not the 12V taillite bulb! hahaha, thanks 67-------twosmoke

 

[my67xr]

I think you need to find yourself a cheap multimeter too, over here they sell them at the cheap $2 shop's etc
Something basic like this would be fine for testing out your bikes' electric's
http://www.walmart.com/ip/Etekcity-...-AC-DC-Tester-Meter-Battery-Included/42556580


Fitting one of these regulator's will stop it blowing bulb's, you just need to bolt it to the frame somewhere for the earth, and connect the yellow wire to the yellow wire coming from your stator wiring.
yamaha FS1 6V regulator

But it may not help your battery charging etc, that's where you need a multimeter to check out the lighting/charge coils' output.
If that is too high then i can work out something else with a different style regulator/rectifier, only has 4 wire's

 

[twosmoke]

Hi 67, yeah, I have a multimeter from the now-defunct radio shack. do I jus start the bike & measure the voltage from the red wire 2 ground? I think the fully charged battery will stop the bulbs blowing, that battery was nowhere near charged w/only 1 cell filled, so I'm gonna try that 1st, if not then maybe a regulator. goin 2 the shop 2moro & tear em a new 1, I should even charge em 4 the bulbs I blew 2, hahaha thanks buddy-------twosmoke

 

[twosmoke]

Hi 67, well I brought the battery back 2 the shop, they're gonna fill the 2 mt cells & recharge it, gotta go back @ 7pm 2 pick it up. I connected a voltmeter 2 the red wire & ground, I'm not 2 sure what range 2 use, they r 10,25,50,250&500VDC, but it moves the needle when I rev it quite abit set on the 10VDC range, how should I measure this voltage? thanks 67-------twosmoke

 

[my67xr]

It should put out around 6.2V or just above at idle, then about 7.2 volt's when you rev it, so set your meter to 25V DC
Any more than that and it'll fry your battery.

 

[twosmoke]

Hi 67, well I had the scoot out last nite, that sprocket fit like a glove & only lost 6 MPH top end, BUT another prob, do they ever end? while in 2nd gear, the engine seemed 2 buck, like slippin in & out of gear, it would rev then skip then bang back in2 gear, what could this possibly be? ignition misfire @ high RPM? fuel delivery? clutch? trans? gearshift mech? IDK WTF is happenin, I'm @ almost 100% w/the resurrection so please advise! thanks buddy,-------twosmoke

 

[my67xr]

So definately a mechanical buck?
Might be the secondary clutch not fully engaging?
It rev's fine the whole way though 1st gear though doesn't it?

Have you managed to do a plug chop yet ?
Hold it wot in top gear and kill the engine while holding the throttle open, bring the bike to a stop and pull the plug out and check the colour on the porcelain right to the base inside the plug

 

[twosmoke]

Hi 67, yeah,it does rev in 1st w/no bucking, it jus does it in 2nd gear, intermittently tho. it sounds more like it slips in & outta gear, bcuz it revs higher between the cutouts. could it be the gearshift rod moving outta engagement? I don't think the clutch is slippin, when it goes, it pulls, minus the chops, of course. no, I didn't do a plug chop, but I looked @ it last nite, & it was lite brn, it was a colder plug tho, the plug b4 that was hotter & the color was jus a tick darker,but not 2 much, I am running a #80 jet currently, it don't seem 2 different than the 75 that was in it as you suggested, oh yeah, would a 4 petal reed block make much of a diff instead of the stock 2 petal? thanks as usual mate-------twosmoke

 

[my67xr]

Yeah the 4 petal reed block will let more fuel in so maybe a bit more top end? but you need a different manifold etc to go with it i think ?

Have to look at the gearbox exploded view to see if there's a detent arm/spring that hold's it in second.
Spring tension may have gone soft ?

 

[twosmoke]

Hi 67, maybe, but I think I saw a couple on treat's site that have the same dimensions & I don't have an xploded view of that gearbox tho IDK if the spring has gone soft, it didn't do that the 1st time I had it out either-------twosmoke

 

[my67xr]

I'm sure i posted a pdf manual one one of your threads before.
Google LB50 service manual pdf if you cant find it

 

[twosmoke]

yeah, 67, ya did, but I'm not sure if I saw an xploded view of the trans, but I'll chk it out again, thanks-------twosmoke

 

[twosmoke]

Hi 67, I found the xploded view of the trans in the manual ya gave me, but now, I don't think its the trans as I don't see nething that could fail cept the spring that is keeping the shaft in the hi range position. I'm starting 2 think its a hi speed ignition miss? I already cleaned the points once, maybe a spot of dirt/oil got on em? I'll check em again, if not, mabe replace the coil? Its 35 years old! but it doesn't buck like that in 1st gear or in low range either, & it revs jus as high, I cant imagine y it doesn't do it, I don't think the clutch has nething 2 do w/it either. thanks,-------twosmoke

 

[twosmoke]

Hi Gang, hey 67, I drained the oil, didn't find ne metal or gear chips ,hahaha, so I took off the flywheel cover & cleaned the points again, took off the clutch cover & inspected the clutch & gears, they all looked 2 be fine, no chipped teeth or ne visible signs of damage, I still think the ignition is intermittently cutting out & high RPM under load. How would I chk the coil? is there ne way 2 chk 4 a high RPM miss? If I hafta replace the coil, I will, I cant have it stutterin like that in 2nd gear @ WOT on the st! thanks,-------twosmoke