New bike, new questions

[NastyBeads]

Hello,

Before I get into my new bike and questions I want to preface this with a big thank you to this amazing community and forum. You guys helped me get from a frame and motor to a beautiful build on my last bike. I will get pics of the last one up as I failed to do it when it was done.

On to the new one. I picked up a 73 for a decent deal that was said to be running. Before I went to pick it up the guy replaced the battery and supposedly a jumper wire he had that was a ground hit the positive terminal and fried this "jumper wire". He thought it fried the rectifier but said he tested the continuity and it should be ok, but gave me a good deal off with the associated price for a PMA/Pamco swap.

I'm not going to lie and say I didn't have a little buyers remorse after this purchase as after seeing the bike in person and the shoddy workmanship that was done. That being said, I'm not sure I want to drop the money on the cost associated to the swap for the new stuff. At this point I would rather try to work with what I have just to enjoy this riding season.

I'll also say I'm not very good at electrical or reading said diagrams. My last bike had nothing and found it easier to install all new wiring to get my last bike on the road with a Hughes PMA and Pamco setup.

I'm going to post some pics of what I'm working with in the I hopes that some of you can provide input of what do so I can get this bike running, or if I'm going to have to start from scratch again with new parts. Ill also note that the bike is a bobber build that only has a headlight and brake light/ kick only and all other accessory wiring was removed from the stock harness so I am working with factory colors.

The first thing of concern I noted is that the wire from the positive terminal going to the ignition switch is not fused with a 20 amp (which I believe it should). Furthermore it has the stock charging system with a regulator and rectifier. The three white wires coming from the alternator appear to be slightly burnt at the connector going to the rectifier. The plug at the rectifier has three white wires that look good, but there is no red or black wire coming off the rectifier connector that I see should go to a ground and the ignition switch (this is where I think his "jumper wires" that got fried were at).

Please look at the pictures and advise if this is correctable or not. Like I said, it's a 73. Thanks in advance for all your help.

 

[NastyBeads]

This was the last one, and again I couldn't have done it without this forum. A big thanks!

 

[fredintoon]

Hi NastyBeads,
I'd advise that you DON'T "drink the koolade" this time and swap in another PMA/capacitor (battery is GOOD)
and even if we don't see the Arizona obits up here, fer Chrissake leave the front brake on the bike this time.
An electronic-advance Pamco ain't exactly cheap and DOES need a rigorously exact install & use procedure
but it's a definite upgrade from the stock 40+ year old points & mechanical advancer.
The multi-pin connector in the photos is in sad shape. (Mine was in about that condition when it melted!)
Best it's replaced. A new multi-pin is good. 3 individual bullet connector pairs will work.
(Those 3 white wires don't care which way they are connected)
The stock '73 wiring only had one fuse and as your bike's wiring don't have signals or E-start, one is all it needs.
There's simplified wiring diagrams on this site that'll help you.

 

[NastyBeads]

Like I said, I'm not real confident in my electrical skills. I read one of the simplified diagrams and thought the two missing wires (red and black) from the rectifier connection, needed a hot and ground. I wired in a black to ground and red to battery positive to see if I could get it to just start. The red wire instantly got hot when I connected to battery and I immediately pulled the connection off.

Also, on the fourth picture there is a blue wire coming from the alternator that is just cut off. What is that for? Neutral switch?

 

[NastyBeads]

Fred, thanks for the response. I am going to jump the coils tomorrow just to make sure the bike runs. With everything I see going on after getting some time to look at it, I'm afraid to put money into this before knowing it starts. The PO said the motor was rebuilt about a year ago, and clearly has a new gasket set on it.

Once I know it runs, I will beat up the search bar in this forum to see how to get it wired correctly and check the components.

 

[figure8]

Seen this?

 

[NastyBeads]

Thanks figure8, I didn't see that. I'm going to read up on testing all the components before I figure out where I'm going to have to spend money. The reg/rect combo looks like it might be a good choice. I jumped the coils yesterday to try and get it to run, but no luck. It sputtered a little like it wanted to. Couldn't figure out if it was missing full spark or fuel. Gonna take off the carbs tomorrow and clean out the jets

 

[NastyBeads]

Random question. On my left side exhaust valve cover, there is a lever on it (like a carb throttle lever). Any idea what this is for, my 78 didn't have it?

Thanks.

 

[retiredgentleman]

Its a de-compressor. It holds one exhaust valve open while you use the starter motor to start the engine.

 

[NastyBeads]

I figured it was something like that. Thanks RG!

 

[Bob Kelly III]

What I do when I am trying to start an unknown engine is this.... first test spark ...I usually hold the spark plug lead but on these bikes that is a very bad idea as you can fry the coil or at least weaken it severely .....so put a spark plug in it and kick it over... if you have spark you can move on to fuel....( although I usually set the points and timing first thing just so I know it's right and don't have to worry about it any more)....
on to the fuel.....I usually just use a shot of quick start or either down the carbs throat with the throttle open then close them again....
if you have spark, and with the quick start or carb cleaner sprey you have fuel and assuming you have at least some compression it should run for a second or two just on the quick start.........
kick it and try starting it.... if it fires up try to raise the RPM to about 2000rpm ... Never rev a cold engine to High RPMS !!!!! they WILL scatter!
once you see that it fires up and runs on the sprey quick start then turn on the gas and see if the carbs will work , another shot of quickstart
and give her another go ..... see if you can get it to run on the fuel in the carbs now....
if it absolutely dies now and refuses to even pop you may have a load of bad fuel, or it may well be flooded pull the plugs and see if their wet
remember never kick the engine over without the spark plugs in the spark plug leads and grounded to the head!!!!!!! or you'll fry the coil.
... if you got this far but it won't run on the carbs you know what the problem is...the carbs ! pull them and clean them and set the floats
and try again.... once you get it to run on the carbs does it run real good of does it miss and stumble or only run on 1 cylinder ?
..... we eliminated the spark first off, and if you don't have spark you have to have it first before it will run so that is back to basics and get the spark working first!.....
.....
I can usually have just about any motor running within 15 minites with quick start.... running right within the hour but these XS650's are another story.... it took me almost a month to get my carbs right.... they were...."Dirty" is all ....LOL and had plugged passageways in the carbs , both of them !
hope that helps !
Bob.........

 

[NastyBeads]

Thanks Bob! That's what I had to do with the first one I had. This one is different ️

I found one if the coils was bad so opted for a Pamco. Pulled apart the carbs and they looked great. Installed the Pamco and wired it to battery to just hear this thing run before I throw any more unnecessary money at it.

With starting fluid, the bike will run for about 2-3 seconds. It sounds pretty healthy, but will not run on fuel. I'm at a loss. I also have fuel soaking the pod filters. Pulled the carbs again to check float valves and float height. Height was dead on. Cleaned out float valves and tested them by putting fuel into the inlet and holding valves closed. It held fuel from coming in so not sure what is wrong.

I'm at a loss of why this thing won't run on fuel. With the starting fluid it sounds good and definitely firing on both cylinders. I hope someone can give some suggestions because I'm out of ideas.

 

[Bob Kelly III]

Sounds like carbs to me too....
the idle circuit in these carbs is critical it must be clean... in the bs34CV carbs you must pull out the Cap they put over the fuel/air adjustment screw to get to them and pull them out.... if you haven't done this, then assume the carbs are still dirty also take off the choke system/plungers
so you can open up the idle passage ways and choke passageways.... then using a can of carburator cleaner blast the passage ways from both directions....
Note# under the idle air adjustment screw is a tiny O ring and a small brass washer ( o ring goes in first brass washer next then the idle screw)
don't loose them !!!!!!!
squirting carb cleaner into the idle air screw hole should come out in the small holes in the carb throat by the butterfly ... when it's clean
the choke circuit is kind'a strange it's main pickup for fuel goes through the Bowl the hole in the outside of the float bowl it must go all the way through to the bottom of the bowl for fresh fuel...( mine were both plugged solid and it took a sharp wire to break through)
also blast the Jets with the cleaner and the openings of the intake there are holes there that need to be clean as well
every hole has an outlet and every hole has to be cleaned but be easy on assembling the parts as they are soft and can break if too much force is used.....
....
Once you get the passage ways clean and the float levels checked again( just to be sure) put the carbs back on and hook up the fuel line
and make sure your not getting an overflow condition gas running out of the carb, then turn off the fuel and hook up a vinyl hose to the bottom of the float bowl and check the fuel level in the bowl by holding the vinyl hose up to the carb and opening the carb drain screw. and turning on the gas again.... the fuel level should be at the top edge of the float bowl or just a tad less .
......
with a cold engine the choke needs to be turned on full once it fires up turn it about half off then in a few seconds all the way off....
.... the idle air screw should be about 3 to 4 turns out from the seat on my 83' Heritage special and doing a dead cylinder adjustment
is a good way to get the idle air screws adjusted perfectly.... or you can do it by ear and get it purty darn close.
..... if your fuel is more than a month old the water in it may have begun to seperate and that will cause problems so fresh fuel
is needed .
once you get it running and can start it on demand then do a carburetor synchronization on the bike... it's a MUST !!!!!
it will smooth out the running and make it quicker responding and more powerful all the way around .
here's a link to my carb thread...
http://www.xs650.com/threads/carb-sync.48939/
I think that's the one with the carb synchronizer in it you can make for just a few bucks !!!
...... Hope that helps !

Bob.....

 

[650Skull]

NastyBeads................73TX650 has BS38 carbs non linked with duel throttle cables. BS34's are a completely different carb.............do not try to work on your 38's from advice given on 34's, it will be all wrong except for the advice to clean all passages.............go to the "Tech menu"..........carbs...........1st thread you will find a link to the "Carb Guide". This will have the information relevant for the set of carbs you have.

In relation to your pics.........regulators need to be in the open, take it out of the tin can......

 

[Bob Kelly III]

Good catch Skull I missed that he had 38's OOPS !!!! thank you !
.....
Bob..........

 

[650Skull]

Bob you would be best to refrain from commenting on my posts............or making any comments towards me..................you are on a mission to have me banned............go round up all those you claim are with you and see the Mods or site admin.........

 

[Bob Kelly III]

i'm not on a mission to have you Banned Skull I am on a mission to make you behave sense you can't seam to do it yourself !
and if that will help you be Nice then I will most certainly try to refrain from commenting about your posts but when you Jump on someone in a nasty way that's not going to happen ! be nice and you'll have no problems with me !
.....
Bob.........

 

[650Skull]

Ron, sorry to here you must get rid of stuff, and your right most people skip over the classified... and your also right about 650Skull
why the administration allows him to remain is a mystery to most here but he does have good input on occasion.
I hope you will get through these rough times and get another motorcycle in the future
best of luck to you.
Bob......

 

[xjwmx]

Few members want to see anyone banned. But nearly all members want all members to see it as a distinct possibility. If anyone wants anyone banned, it ought to be a message to that person.

 

[NastyBeads]

As far as carbs go, I'm not sure what I have. I will post pics so you guys can help me. I highly doubt they are the factory 73 BS38s. They have a single throttle, four holes in the front inlets not including air horn, brass floats and no drain barb on the bowls.

The good news is I got this baby idling for a little while. I messed with the Pamco plate a little and got it to idle, however, rough. I was getting backfiring from the carbs, then some nasty ones with flames from the exhaust pipes. I put a timing light on it and tried to get it within the F range, but the damn thing was bouncing around BAD and didn't really find out where the advance was. I ran out of time last night, so after looking around today, I need to check the valve clearances and timing chain adjustment. Then after I get the carb properly ID'd I can set my air/fuel. The floats are at 24 mm right now and I tried anywhere from 1-2.5 turns out. I'm happy to hear it run for the first time, but concerned at why I'm having such an issue getting this to run smoothly as the PO said it was his daily driver before he got a car and parked it....but i guess we know how that goes.