reverbtank
XS650 Member
Just got a beautiful '73 TX. Starts on the first kick, but I'd like to use the electric start as well. When I pull the decompression lever, the engine turns over, but never starts. Any ideas?
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How do you use the decompression lever to start a '73 TX?
- Thread starter reverbtank
- Start date
You're using it the right way. The decompression lever is a combination of that and the start button. What I'm guessing your problem is is low voltage. The ignition needs I'd say pretty near 11 volts to fire the plugs strongly enough to start. The electric starter sucks a lot of juice. It may be pulling the battery voltage down too low to adequately power the ignition at the same time. When you kick it, there's no extra draw on the battery. All it's voltage is free to power the ignition.
You might want to test the voltage at the coils too. Low voltage to the coils is a common problem on old bikes. You start out with around 12 at your battery but by the time it goes through all the old connections and switches, you may only end up with 9 or 10 volts at the coils. Two common big loss points are a dirty ignition switch and/or a dirty kill switch.
You might want to test the voltage at the coils too. Low voltage to the coils is a common problem on old bikes. You start out with around 12 at your battery but by the time it goes through all the old connections and switches, you may only end up with 9 or 10 volts at the coils. Two common big loss points are a dirty ignition switch and/or a dirty kill switch.
How old is your battery? Old batteries can charge up ok but not have the ability to put out much cranking amps.
Do you have a small battery charger? Not a car battery charger, they put out to high a voltage and current.
A small charger with 1.5 amp rate is about right. You can buy one from a lot of places. Wal Mart sells one. It even has a Motorcycle on the box.
Use a charger like this to fully charge your battery.
Opp's, Check the fluid level in your battery first, If low add enough distilled water to bring the level up to the fill line.
Once charged check the voltage at the battery terminals. It should be 12.5 or maybe a bit higher.
Then turn on the key and engine stop switch. Leave lights off. Check battery voltage again. Use this voltage as a reference voltage when checking voltage elsewhere. Such as the coils.
Leo
Do you have a small battery charger? Not a car battery charger, they put out to high a voltage and current.
A small charger with 1.5 amp rate is about right. You can buy one from a lot of places. Wal Mart sells one. It even has a Motorcycle on the box.
Use a charger like this to fully charge your battery.
Opp's, Check the fluid level in your battery first, If low add enough distilled water to bring the level up to the fill line.
Once charged check the voltage at the battery terminals. It should be 12.5 or maybe a bit higher.
Then turn on the key and engine stop switch. Leave lights off. Check battery voltage again. Use this voltage as a reference voltage when checking voltage elsewhere. Such as the coils.
Leo
Hi reverbtank and welcome,
like they said, the starter is sucking up so much power that there's not enough left to run the ignition.
A no-cost check is to temporarily connect a car battery to your bike battery with booster cables and try the E-start.
If the bike starts when boosted your bike's battery is low/weak/needs replacing.
like they said, the starter is sucking up so much power that there's not enough left to run the ignition.
A no-cost check is to temporarily connect a car battery to your bike battery with booster cables and try the E-start.
If the bike starts when boosted your bike's battery is low/weak/needs replacing.
The Ignition switch is one common voltage drop area. Some pics of a rebuild here; http://www.xs650.com/threads/early-ignition-switch-r-r-70-73.42161/#post-421845
Just a couple of pics to refer to how it comes apart, goes together.
Like deese guyz sez find all the dirty electrical connections and it will be a happy bike. Much easier in the garage instead of out on a dark road somewhere.
My stock but maintained 73 would regularly electric start even after long sitting. Doesn't hurt to do the drill; gas on, choke on, a few kicks, then ignition on and pull the E-leg lever.
Just a couple of pics to refer to how it comes apart, goes together.
Like deese guyz sez find all the dirty electrical connections and it will be a happy bike. Much easier in the garage instead of out on a dark road somewhere.
My stock but maintained 73 would regularly electric start even after long sitting. Doesn't hurt to do the drill; gas on, choke on, a few kicks, then ignition on and pull the E-leg lever.
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angus67
Welder's penetrate deeper!!
don't jump it with the car/truck running.
....in the middle of nowhere, with a girl on the back, in the rain, the night before a major final exam in thermodynamics.....(don't ask me how I know all that...)
reverbtank
XS650 Member
Great advice, thank you all. The battery seems old, but did take a charge overnight. Still lacks the power to fire it up from cold, so I'll get a new battery and check the switches.
Anyone know why the '73 got the 'TX' name?
Anyone know why the '73 got the 'TX' name?
The TX750 was intro'd in 73 and Yamaha was was uniting the 4 stroke street twins under one TX "marketing brand". Then when the poorly executed TX750 became a pariah in the minds of riders, the XS name was resurrected in 75 to distance the "good ole' reliable 650 from the TX fiasco.
Two years of the 650 model got the TX designation
The 1973 TX650 and the 1974 TX650A
Oddly the 73 - 74 model changeover made the most significant changes to the XS650 engine and frame during the entire production run. Not really hinted at by the mere addition of an A to the the name.
Two years of the 650 model got the TX designation
The 1973 TX650 and the 1974 TX650A
Oddly the 73 - 74 model changeover made the most significant changes to the XS650 engine and frame during the entire production run. Not really hinted at by the mere addition of an A to the the name.
NOTE: some of what appears below is personal opinion based on observations, rumours and what a guy I met in a bar told me one time, and some of it is verifiable fact based on extensive research, reading lots of magazines and knowledge transferred from the automotive sector.
I think that the Yamaha marketing department was, collectively, on some sort of drug trip all through the late 60's and early 1970's (it was the "Age of Aquarius" afterall) as they seemed to change their system of model designations nearly every year and most of these designations provided no real clue as to what the product actually was (XS1, XS-1B etc.....). Then they tried the TX branding scheme which made a bit more sense because "T" presumably stood for "Twin" and "X" was the cool letter of the 1970's (just like "R" is the cool letter in motorcycle model names now...CBR600RR etc. etc.), and then there was a number which referred to the approximate engine displacement in cubic centimeters - and finally sometimes you see a letter to designate the model year.
The problem was that one of the TX clan (the TX750) was NOT a good bike - even though it had some really neat technology - the Omni-Phase engine balancing system which made the thing feel like a four cylinder bike rather than a bone-shaking twin. Unfortunately, in its first year (1973) the TX750 suffered from serious engine durability problems whcih were actually caused by the Omni-Phase balancing system. Also, it was a bit of dog on the road compared to the sparkling, fast, cool and sexy sounding Honda CB750 Four and the fast and furious Kawasaki H2-750 triple and slightly more civilised Z1-900, not to mention the quirky but wonderful Suzuki GT750 LeMans or "Water Buffalo" as it is usually called (aka the "Kettle" in the UK). The second year '74 TX750 was actually an OK bike, but the model's reputation had taken such a huge hit that the 750 bike was canned after only two model years and tons-o-dough in R&D spending. Those bikes are rare birds now. I've only ever seen one and that was in the 70's when a classmate of mine had a '74 TX750 - which my 1975 XS650B could eat alive in a drag. BTW - your '74 TX650 is (as far as I know) essentially identical to my old '75 XS650B.
After the TX750 fiasco, Yamaha simply had to change their model designations yet again to try to back away from the unsuccessful 750 model. So, eventually they got it right (I would say in 1975 - but others may differ) and developed a model designation system which actually they stuck with for more than a few weeks:
Anyhow, let's try another mid-1970's Yamaha model:
....those wacky marketing folks - gotta love 'em.
The amazing thing is that despite the turmoil in the marketing departments of these companies, for the most part, the engineers keep coming up with really good products and with very few exceptions (Yamaha TX750, Honda Civic Del Sol), they have done so for decades.
Engineers are cool. Be an engineer.
I think that the Yamaha marketing department was, collectively, on some sort of drug trip all through the late 60's and early 1970's (it was the "Age of Aquarius" afterall) as they seemed to change their system of model designations nearly every year and most of these designations provided no real clue as to what the product actually was (XS1, XS-1B etc.....). Then they tried the TX branding scheme which made a bit more sense because "T" presumably stood for "Twin" and "X" was the cool letter of the 1970's (just like "R" is the cool letter in motorcycle model names now...CBR600RR etc. etc.), and then there was a number which referred to the approximate engine displacement in cubic centimeters - and finally sometimes you see a letter to designate the model year.
The problem was that one of the TX clan (the TX750) was NOT a good bike - even though it had some really neat technology - the Omni-Phase engine balancing system which made the thing feel like a four cylinder bike rather than a bone-shaking twin. Unfortunately, in its first year (1973) the TX750 suffered from serious engine durability problems whcih were actually caused by the Omni-Phase balancing system. Also, it was a bit of dog on the road compared to the sparkling, fast, cool and sexy sounding Honda CB750 Four and the fast and furious Kawasaki H2-750 triple and slightly more civilised Z1-900, not to mention the quirky but wonderful Suzuki GT750 LeMans or "Water Buffalo" as it is usually called (aka the "Kettle" in the UK). The second year '74 TX750 was actually an OK bike, but the model's reputation had taken such a huge hit that the 750 bike was canned after only two model years and tons-o-dough in R&D spending. Those bikes are rare birds now. I've only ever seen one and that was in the 70's when a classmate of mine had a '74 TX750 - which my 1975 XS650B could eat alive in a drag. BTW - your '74 TX650 is (as far as I know) essentially identical to my old '75 XS650B.
After the TX750 fiasco, Yamaha simply had to change their model designations yet again to try to back away from the unsuccessful 750 model. So, eventually they got it right (I would say in 1975 - but others may differ) and developed a model designation system which actually they stuck with for more than a few weeks:
- 1975 XS650B - "XS" = 4-stroke street bike, "650" = nominal engine displacement, "B" = designator for the 1975 model year;
- 1976 XS650C - "XS" = 4-stroke street bike, "650" = nominal engine displacement, "C" = designator for the 1976 model year;
- 1977 XS650D - "XS" = 4-stroke street bike, "650" = nominal engine displacement, "D" = designator for the 1977 model year;
- etc...up till the 650 twin model was canned in 1984, except that in 1979 they began adding in all sorts of stuff about Specials, Midnight Specials, Heritage Specials and Special II's etc... - just as Honda started in with Nighthawks and other marketing foolishness from their beauty police (the auto industry nickname for styling and marketing folks).
Anyhow, let's try another mid-1970's Yamaha model:
- 1975 RD350B - "RD" or "ring-ding" = 2-stroke street bike, "350" = nominal engine displacement, "B" = designator for the 1975 model year;
- 1976 RD350C - "RD" or "ring-ding" = 2-stroke street bike, "350" = nominal engine displacement, "C" = designator for the 1976 model year;
- ....ok, that seems to work, for a while....
- ....and then MamaYama started in on XJs, and then they started giving their bikes names that sounded like porn stars (Seca, Maxim..), 1960's folk groups (the Venture), brands of toilet paper (the Venture Royale....), or names that sounded like late night Japanese B-movie monsters (the V-MAX.).....then..who the he!! knows...
....those wacky marketing folks - gotta love 'em.
The amazing thing is that despite the turmoil in the marketing departments of these companies, for the most part, the engineers keep coming up with really good products and with very few exceptions (Yamaha TX750, Honda Civic Del Sol), they have done so for decades.
Engineers are cool. Be an engineer.
Think it was cycle world that published this along with eulogies for several other motorcycle turds.
The TX750 by Yamaha
is smooth and slick as a Bananaha.
Counter weights revolve hard
on chain by the yard
And oil leaks thither and Yanaha.
Rumor has it that the TX750 is why Yamaha (had to) invent Yamabond.
The TX750 by Yamaha
is smooth and slick as a Bananaha.
Counter weights revolve hard
on chain by the yard
And oil leaks thither and Yanaha.
Rumor has it that the TX750 is why Yamaha (had to) invent Yamabond.
....and perhaps that goofy emergency headlight warning thing-a-ma-jiggy?
Hi Pete,
I dunno about that thingie being goofy. I reckon it's a good thing.
Yes, if one of your headlight filaments craps out at night it's effin' obvious.
But in daylight, not so much.
That goofy gadget lights up to tell you that's it has either switched to the other filament or is warning you that it's burned out.
On a bike that don't have one you could be running dark in daylight and never know it.
...Engineers are cool. Be an engineer.
Well said, Pete.
Given a choice, It's said that:
Mechanical engineers make weapons.
Civil engineers make targets...
The other key piece of info for the layman is how to tell one engineering discipline from another. Here is a handy guide:
If it doesn't move - its civil
If it moves - it's mechanical
If it moves really fast and is made of aluminium - it's aerospace
If it moves so fast you can't see it - its electrical
If it's green and is singing "kum-by-yah" - its environmental
If it smells really bad - its chemical
If it's really dark - it's mining
If it's really hot - it's metalllurgical
If it doesn't work - it's computer systems.
There: engineering - a mystery no longer!
If it doesn't move - its civil
If it moves - it's mechanical
If it moves really fast and is made of aluminium - it's aerospace
If it moves so fast you can't see it - its electrical
If it's green and is singing "kum-by-yah" - its environmental
If it smells really bad - its chemical
If it's really dark - it's mining
If it's really hot - it's metalllurgical
If it doesn't work - it's computer systems.
There: engineering - a mystery no longer!
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reverbtank
XS650 Member
While I'm getting to know my new bike, does the red light on top of the headlight case indicate that the headlight is on or that I have a bulb out (which my low beam is out)?
70 to 73 the red lens in the top of the headlight bucket is the high beam indicator, It uses a tiny twist lock "wheat bulb" in a fragile socket, IMHO if it lights don't mess with it. I replaced one with an led.
I dunno guys. Can you scrape together enuff re-bar and concrete for this?
Even though it was detonated at a height of 2 miles, the rock below was turned to ash.
That was back when we were doing those silly "duck-and-cover" drills.
About as useless as tweezers for kickstarting this XS650...
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