new to forum, new bike, pics!

coughing skunk

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I've been reading and reading this forum for the past week in anticipation of picking up my new bike, a 1973 TX650. Anywho, here are some pics and some of the questions/concerns that I have.

I just picked this thing up two days ago and rode it 70 miles home with only two hiccups. The battery that came with the bike was dead and left me on the side of the highway at 12:30 in the am. Luckily, we had brought another battery and once installed we made it home hitch free. Then while cruising at ~60 the bike would choke and then once it puttered and died. I pulled over and a minute later and a couple of kicks and I was back on my way.

The few concerns I have are as follows::yikes:

At higher RPM (maybe 4500-5000? no tach.) the bike would start to sputter and die like it wasn't receiving fuel. If I backed off it would act fine. My initial thought was jets, as this bike has K&N pods on it and some sort of aftermarket(?) muffler that looks to lack baffles. Yesterday I began looking over the bike and checked the plugs first and to my surprise they were both dark, as if running rich. I then looked at the carbs and noticed the carb holders are cracking and have been repaired once before. I read here that holes in the carb bladder can produce the same symptoms that I've described but the carbs were just rebuilt (I saw the receipt), so I'm assuming that at higher RPM the vacuum created begins to suck air through the cracks in the carb holder, thus producing my problem.

The next issue that I seem to be missing my choke?? Can I get away with adjusting something else on the carb during warm up, or do I need to get the choke?
Check out this picture

photo8.jpg


My clutch was really really really stiff, but I took the cable off and reran it and lubed and greased all associated parts, and it made it tolerable now. On the ride home my hand cramped it was so stiff.

Another confusing problem is that in 2nd and 3rd gear only the bike will slip out of gear at some point until I back off the throttle, at which point it reengages. I read that its maybe the clutch springs? Or a mis alignment of the pressure plate??

Also, the bike has no tach. This is fine with me, but I think the tach sensor is unplugged, and again fine. Could someone please verify that the tach sensor is in fact the sensor in the picture below?

photo9.jpg


Are these the stock pipes? I can't imagine so, as there is no baffling on the inside and the look shorter than others.

photo6.jpg


And finally the bike!

photo4.jpg



Any and all help is appreciated!

Posted via Mobile
 
Hi, skunk! '73 TX owners unite! :) Welcome!

I'm off to eat supper, but just very quickly, you appear to have Mikuni roundslides there... not the original Mikuni BS38s. That's not a bad thing, but you do need an enrichener. Your carb appears to have been molested. :(

Also, those carb holders look to be in very poor condition and may be part of your fuel delivery problem. You'll want to look into replacing them with units from JBM Industries (one of our compatriots here who makes them for the community); the rubber compound in them is well tolerant of ethanol fuel.

Have a read through the Tech link up top, especially the sections on what you need to do right after bringing your bike home... there's a "laundry list" there. At least your bike is running! :)

Oh, among other things, you'll want to lose that clear fuel line, which can get brittle, and use Motion Pro Gray. Also, please use spring clamps at all junctions, and run in-line fuel filters. You can thank me later! :)

TC
 
welcome,
the sensor pic isn't a tach sensor. its the neutral light switch. i agree w/ teecat, i've never seen carb holders in that bad of shape. good luck with the new bike!
 
welcome,
the sensor pic isn't a tach sensor. its the neutral light switch. i agree w/ teecat, i've never seen carb holders in that bad of shape. good luck with the new bike!

Oh, awesome. I'll grab the schematics and run a light for that.

Yeah, the carb holders are trashed. I was looking at the JBM holders for the 38's but they were all out and Don said to check back in 90 days :shrug: but now that I've got the round slides...

Posted via Mobile
 
Oh, and make sure that the new carb holders are the correct internal diameter for the outer diameter of your carb spigots!

And how are you starting the bike from cold without an enrichener, btw?

TC
 
Oh, and make sure that the new carb holders are the correct internal diameter for the outer diameter of your carb spigots!

And how are you starting the bike from cold without an enrichener, btw?

TC

It just took a couple of kicks, couldn't tell ya. I started it to ride it home and thats it. Haven't started it since, as I've been doing those things on the laundry list in the tech section.

Posted via Mobile <--- not true

edit: It appears I have the enricher circuit, just no levers for them, they twist open and closed..
edit II: I lied, it appears the enricher circuit works correctly, it pulls up and down, just with no lever.
 
You can see the silicone someone smeard on the carb holders on the motor side of the hose clamp. PO'S quick fix!!!!! bike looks looks sweet by the way.

Posted via Mobile
 
transmission slipping out of gear could be shifter pawl needing adjustment or worn engagement dogs. Shifter pawl is under kickstart side of cover. Welcome to owning an old bike, hope you arent scared to dive in.
 
Odds are very good your charging system isn't. Read the Curly's charging guide, start by checking your brushes. Get a repair manual. Either the factory Yamaha manual or a Haynes Clymer version. You will have some extra fun because the PO has changed a lot of stuff and you won't know what he changed, why and if it works. The factory tach was mechanical the drive is located at the front of the RH engine cover, you don't really need one, the engine will sound like it is going to explode long before you reach redline. And set idle where it runs smooth but not racing. It sounds like your clutch is slipping, you will get the chance to go through all parts of it figuring out why. First step is a complete removal, cleaning and proper adjustment of the ball ramp mechanism in the LH cover.
 
Move or remove that chain guard, that awful slapping noise you hear is that abortion. Welcome to the old motorcycle owners club. You should not have bought this bike. But that train has left the station. You will either learn to be a real old time mechanic or quickly get VERY tired of sitting along the road somewhere scratching your head and kicking the damned bike. Or sell it it or leaving it sitting in the back of the shed or in the yard somewhere. This is not a 10 year old street bike that just needs a new battery every three years or so. It is a real old timey mechanical contrivance that thrives only under constant mechanical TLC. You will always have an ear cocked straining to catch an early clue of the next mechanical disaster about to occur. THAT is part of owning an OLD motorcycle. Learn to love it or get rid of it now before it drives you to despair.
 
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Sorry a I don't mean to sound so mean..... I can't help but look at that bike and see a PO who wanted to build a bob/tracker, did the cosmetic stuff and THEN tried to make it run reliably. He figured out he wasn't up to it, couldn't afford to pay someone else to do it and sold it.
 
The VM carbs come in right and left-handed versions. The difference is the location of the idle speed adjusting screw. It should be on the side facing out so it's easily accessible. The left carb in your pic may be a right-handed version, or check the other one - maybe the P.O. just has them mounted on the wrong cylinders.
 
Move or remove that chain guard, that awful slapping noise you hear is that abortion. Welcome to the old motorcycle owners club. You should not have bought this bike. But that train has left the station. You will either learn to be a real old time mechanic or quickly get VERY tired of sitting along the road somewhere scratching your head and kicking the damned bike. Or sell it it or leaving it sitting in the back of the shed or in the yard somewhere. This is not a 10 year old street bike that just needs a new battery every three years or so. It is a real old timey mechanical contrivance that thrives only under constant mechanical TLC. You will always have an ear cocked straining to catch an early clue of the next mechanical disaster about to occur. THAT is part of owning an OLD motorcycle. Learn to love it or get rid of it now before it drives you to despair.


I am very confused with this post. I don't think I ever stated that I wasn't mechanically inclined, or up to the challenge of cranking on an old motorcycle. Quite the opposite really in both categories. :banghead: I'm not going to waste my time attempting to prove my qualifications. I bought this as a project bike with the knowledge that it needed work. I posted on this forum for suggestions as how to diagnose and fix this thing. This is my first bike and I'm (obviously) green in that respect, so all help is very much appreciated. In regards to the chain guard, I have never heard a slapping noise but thanks, the guard will come off.

Please don't take this as any sort of attack gggGary, but just like my grade teacher used to say 'when you assume things you make an ass out of you and me'.

Aside from that I have made progress thus far. I lubed the clutch cable and all linkage associated with it (ball ramp mechanism, etc) and that reduced the stiffness to dare-I-say an enjoyable level. I changed the oil and cleaned the filter and found that the gear holding spring was snapped off. This is (hopefully) the problem with 2nd and 3rd gear slipping out of gear. I've ordered new carb holders as well as the previously mentioned spring. I ordered a new clutch pushrod seal as mine is leaking the tiniest bit. Other than that there are no leaks. I also ordered new brushes as I went through the charging system and both the brushes were worn out. This area is my specialty as I've been trained (read: was a slave in school ) to become a EE some time ago. I am also in the market of sourcing parts for the magneto alternator swap, as I see that being the best solution to a rather bad charging system.

The VM carbs come in right and left-handed versions

So it turns out that I have two right hand versions of the VM carbs. More on that later..
 
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Those mufflers are aftermarket copies of Sporster mufflers. They're a bitch to get to seal at the pipe but I love the look and the not too loud sound you can get by packing each one with a brass wool scrubbing pad. I'm running the same pipes on my '83.
 
OK Mia Culpa, I get some of my best exercise leaping to conclusions. I reread your first posts and looked at the pictures. It did kinda sound like the stuff someone who knows nothing about motorcycles would post, just sayin.... And this bike will get your feet wet in the wonderful world of old abused motorcycles. Good for your electrical knowledge, it helps two ways; you can fix the electrical and you are less likely to blame carb problems on it. :laugh: What attracted you to this bike? Just wondering... My statement about you should not have bought it is because it appears that the PO was an idiot. Those carb holders, fuel lines with no clamps, the scraped off the crap, appearance of the aluminum etc etc.and we can't even see the wiring work. It can be really tough and frustrating dealing with ANY old motorcycle. Working on one that has been thoroughly fuggled by the PO can piss off a saint. Best of luck to you and I hope you will allow me to suggest possible answers to questions you may have. :bike:
 
I thought latin was a dead language?? ha, no hard feelings gggGary. I look forward to recieving some schooling on these old bikes

What attracted you to this bike? Just wondering...

Got what I feel was a good deal for an old running bike with potential. Guess time will tell :laugh: but I've got faith, blind or not.

My parts should be here in a couple of days, and then I'll be able to let you all know what else is broken.
 
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