honda cb500t start problems

[eddie axeman]

i have a 1975 honda cb 500t i have recently started to get it ready for the road it has been stood for a few years when it starts it will only run on the choke and it is hard to get started if you use the electric start after a few times it melts the earth to the rectifier.ihave put new coils on and caps new spark plugs new condenser new ignition switch new air filters.i have stripped and cleaned the carbs i have also put new fuel filters in line .the next stage is new points and timming check. any ideas greatly apreciated.also does any one know if the horn switch should double up as a flasher switch as the switch you can push in and to the side one way the lights flash but the horn dosent work thankyou :unsure:

[shaggy696969]

Sounds like the contact to the starter is corroded also, Just had the smouldering solenoid thing on a XS1100 thats been stood. No idea about the rest sorry good luck.

[matthewmosse]

I recon the lighting / horn switch meant to do that as my cb550 of the same age packs the same features. My best geuss on the electrics front is the earth cable battery to ground (the thick one) has a bad earth and so the current is somehow shorting through the reg insted? clean the major earthing contacts rond the earth cable and engine? carbs been cleaned recently? the 70's 4 cylinder cb500 ones tend to gum up easily as anything..............

[Creature]

carbs

check the jets carefully also check foat height as this is often wrong.

check the throttle slide for wear and the O ring

check the air screw to make sure not seized and at required setting (if memory serves me correct 1 1/2 - 1 3/4 turns out but check ya manual)

also the carbs were sods to balance - if they are unbalanced starting will be hard

for the burning wire check the loom carefully on the ignition curcet thers probally either a trapped earth wire or the wires from the switch are wrong. Most early hondas ran a negative wire for teh start switch and many people stick it in positive by mistake,

also remove the right hand switch gear and check carefully especially were wireing goes into the switch for chaffing. try using starter with switch not on the handle bars and see if wire still burns out -

i would check all the wires that are involved with the ignition even ya points wires

if still problem exsits then its time to carefully reemove the loom covering and check carefully.

best o luck

[Borg]

check the intake rubbers, and the air filter as well

[eddie axeman]

i will try the things that you have mentioned i will keep you posted as to who was right .next stage is paint it camouflage and make a side car and chassis for it so it will be ready for the winter.thakyou for your help.hopefully their will be some pics of it when done....

[bird]

Watch out for the starter motor clutch - Its three little metal studs held in by springs. Make sure its working ok, as it can seize, and the three studs fall out of their housing and chew up the alternator. I recall Fred Hutchings in Exter telling me three weeks after I bought one of bastard things from him that "oh yeah, thats quite common, with the 500T that is" and then refusing to fix it under the warranty.
That was in 1981 and I still haven't forgiven the bastard.:mad:

It had that weird switch gear too, And the torsion bar valve springs shatter as well.

enjoy!:unsure:

[eddie axeman]

i know that they are c**p but luckily i have a couple of spare engines and lots of bits so i will ride it and have some fun until it wont go no more .then i will see if i can fit a modern cb500 engine in the frame .i have spent a little to much getting it going to give up.had it standing in the shed i know its not worth much but somtimes with these projects you can get carried away with it . then it becomes an obsession.so u juast have to carry on .i suppose it is a i will make it go scenario.everybody is waiting to see the rat finished so it must be done.:thumbsu:

[eddie axeman]

it still dosent run properly i think i might try some diffrent carbs unless any body has any other ideas

[odie]

easiest answer is "A GALLON OF PETROL AND A BOX OF MATCH'S" :D
Just kidding petrols to expensive!
The 500T was always a dog from day one, its technicaly a stretched "Black bomber", which were fun but still prone to problems.
Try putting the new CB500T motor into it, will be 100% better.
have fun:thumbu:

[BigSteve]

I had one of those old CB500T's a few years ago. Cam followers made out of cheese, and yes, they are a bugger to start if the carbs are even a smidge out of balance. :(

Hello, by the way! :D

[eddie axeman]

its only a rat bike for winter painted in camo coluors it will evetually have a home made side car onit made with an indespension unit and a home made tub bit like a ural .only if it will run:D

[Creature]

u stick a chair on it and within 5-6000 miles will rip the cam followers out its just not up to the job as metioned elseware is only a bored out 450 black bomber - now taht engine will pull a chair all day long but you will br fighting the collectors

[John Hopkins]

If the earth wire from the rectifier is burning up you must have a shorted or leaky rectifier Think about it, a diode is like a one way valve for electricity, one side of it is positive voltage and the other is negative..the rectifier is made of four diodes, if it is encapsulated (made within the last 35 years) it may have a capacitor inside the encapsulation so you can discount that..Two of the diodes go to the earth wire and they are wired so that they are at zero volts..the current runs from earth to the positive side of the battery driving anything that is connected to it, if the rectifier is really hot it has burnt up and the wire is shorting your battery to earth...the cause of the initial fault is probably the rectifier was not properly earthed in the first place so check with a multimeter on the lowest resistance range to make sure that the rectifier earth is a dead short to the negative side of the battery....John other than that anything such as the horn shorted out will overload a rectifier and probably the battery as well, so you could take the horn out and connect two wires from it to touch on an old battery to see if it sparks or honks...

[eddie axeman]

cheers john that makes a lot of sense i will try that ...do you have any ideas for the carbs it would be much appreciated i have checked the settings over and over again and cleaned them several times .i also found that the battery was knacked as well i dont know if the bike killed it or not as it was just an old battery laying about i didnt want to put the new one on ubtil i had it running propley:thumbsu:

[eddie axeman]

after all the problems i have conseede defeat and sent it to shaurn at the garage to be fixed will soon know what my little rat will cost to fix:unsure:

[gothtec]

1975 honda it starts it will only run on the choke and it is hard to get started

Sound familier.....

I had the same problem until I figured that choke on was actualy choke off!!! Bloody haynes wouldn't tell me which was which. Maybe yours is the same problem, therefore you don't have a problem :D

[eddie axeman]

i have found thier is a problem with the carbs they are not set propley and they dont like the new open filters the origanal filters seem to only be available in america:rolleyes: