Author Topic: I thought the GS was bad...  (Read 529 times)

Offline mr72

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I thought the GS was bad...
« on: May 24, 2021, 11:22:30 AM »
You all are likely aware of my trials and tribulations making my GS500 "just run". And my aversion to carburetors as a result. And how I have, through the necessity forged from adversity, become somewhat knowledgeable about how to make a motorcycle with CV carburetors run...

Well, you might recall I ride with my dad, it was his desire for a riding buddy that prompted me to buy a motorcycle to begin with and started this whole adventure. My dad still has a fondness for old motorcycles, those which were new when he was young. He's enjoyed the reliability of his Honda Shadow 750 and finds it to be a capable and comfortable bike, but he still had some desire for a "scrambler" as he puts it. He bought a 2011 or so TU250X that required some work to get it right, and he put a set of trials tires on it and now i's a "scrambler" and it's been his first choice to ride most of the time even though it's woefully underpowered for TX roads. We actually rode out to my parents' eventual retirement property some two hours from here into the hill country and he took the TUX and I took my GS500, which revealed the glaring weakness of the TUX. Max speed is about 65 but it can't maintain that speed if there's any incline, so the hill country and 9 miles of a 70mph highway each way was not any fun at all. That train of cars behind us as we ran that bike flat out up hills at 45 mph was not very nice.

So the plan was hatched to find a "Scrambler" that would handle gravel roads and also comfortably cruise at 70mph. And one that would be at least as reliable as his VT750. And this can't be like a KLR650 or even a DR350 because the seat height is just too tall on these dirt-oriented bikes. He needed something with size and ergos like his TU250X.

My dad is constantly cruising Craigslist in search of something that'll match with his current needs and former desires. He found a pretty well sorted '72 CL350 survivor on CL and we drove the hour away to pick it up. It's been a few weeks since he got it home and it's been a big exercise in buyer's remorse, I'm afraid. I suppose I should have talked him out of it.

First was a rash of cosmetic and quasi-functional stuff. The guy who sold it to him built it up to sell. He does this a lot, buys incomplete or project motorcycles and then adds a dash of this and that to make a complete bike and flips them. He's a retired guy who basically does this as a hobby. In this case, he kind of styled this like a hipster-themed Scrambler with real loud pipes (cheap Emgo looks like), tiny gauges (original speedo was long gone), Shinko 244s and a flat tracker handlebar plus one of these universal "cafe" type hard as a brick seats. But the bike seemed to be mechanically solid, had been upgraded to a CB450 front end complete with disc brake, ran fine and my dad brought it home.

The first order of business was turn signals, which were totally missing from the bike. Turns out I had a set that were perfect, chrome bullet type but too small for my Bonneville but just right for this bike, so I donated them to the cause. He also switched the handlebar for an alloy ATV handlebar I previously had on my Triumph. He did a "shake down" ride and the throttle cable got stuck due to a missing lock nut inside the throttle assembly, making it idle at >2K rpm. So he fixed that by putting a zip tie in place of the lock nut. Next problem was the gauges, which aside from the speedo being in kph, it was also too small for my dad to read without reading glasses which basically defeats the purpose. And he finds no need for a tachometer anyway and hoped to just chunk it. Turns out the bike has a custom (that is, made by the PO) wiring harness with none of the wiring in it for turn signals, so I'll be running wires and putting a turn signal relay on it any time now.

The PO had the bike parked on the center stand when we got there to check it out. He said he parked it that way most of the time because on the side stand, with the petcock left on (manual only), it tended to let the left carb get too full and flood, but on the center stand it was not so bad. Well, during a series of "shake down" rides, my dad discovered that the left carb leaks all the time, running or parked, leaking fuel right near the exhaust, which is a certified bad thing. So now I'm on deck not only to add turn signals to this thing, but also to figure out what's wrong with 50 year old carburetors. My guess is there's a hole in the (brass) floats, or the float needle valve is just completely not installed correctly so the fuel never shuts off.

He was supposed to come by my house yesterday and we were going to pull the carb off and let me take a look. But when he went out to fire up the old CL, one of the (non-original ... probably from TEC bike parts...) rear shocks had separated the shaft from the end, and he didn't have a spring compressor to put it back together. So now the plan is to pull the carb and bring it over to me maybe this afternoon, and he's going to cobble together a spring compressor from hardware store parts and try to put the shock back togeher.

So he's ridden it like 20 miles and spent a ton of time tinkering with it. He bought it being convinced that these 50 year old Hondas were legendary for reliability and were also very simple to work on and maintain. I contend that his 2011 TUX is a lot more simple to work on and maintain because you just have to start it, ride it, and change the oil every now and then, and that's 100% of the work you have to do on it. There's nothing simple about a motorcycle with two CV carburetors that are half a century old along with points ignition and who knows what modifications that have been done in its extremely long lifetime.

Given that it was in Killeen before and now it's in Austin (a rich market for instagram-worthy selfie bikes like this), I think he could put the turn signals on it and sort out that carburetor and sell it for more than he paid for it. Then maybe he'll give up on his desire for a do it all bike and just sell the Shadow and his DR200 which he doesn't really want anymore, put all that money together and buy a Royal Enfield 650. Fuel injection, ABS, a warranty, and the cosmetic impression of a 70s motorcycle. We'll see. But either way, I have a far more needy old Japanese twin to work on for the next few weekends.
« Last Edit: May 24, 2021, 11:28:13 AM by mr72 »

Offline cbrfxr67

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Re: I thought the GS was bad...
« Reply #1 on: May 24, 2021, 01:48:38 PM »
"buys incomplete or project motorcycles and then adds a dash of this and that to make a complete bike and flips them"  =my dream retirement

"Hondas were legendary for reliability and were also very simple to work on and maintain" 

I agree, he should dump that turd to somebody with more money and keep looking!  Great read btw,..always enjoy your commentary!
"Its something you take apart in 2-3 days and takes 10 years to go back together."
-buddha

Offline mr72

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Re: I thought the GS was bad...
« Reply #2 on: May 24, 2021, 02:35:03 PM »
I agree, he should dump that turd to somebody with more money and keep looking!

It's not about money. It's about his tolerance for fiddling with a motorcycle vs. his desire to just ride it. He wants the kind of forget about it reliability of his TU250X but with twice the power and the air of authenticity of an actual motorcycle from yesteryear.

Offline Bluesmudge

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Re: I thought the GS was bad...
« Reply #3 on: May 25, 2021, 09:44:23 AM »
Power to weight ratio:

'73 CL350: 33 hp/346 lbs (dry) = 0.095
'11 TU250X: 24 hp/326 lbs (wet) = 0.074

Assuming we trust the '73 power and weight figures (I don't) you are looking at a ~20% power to weight ratio improvement IF you're dad can get the CL to run as good as it did in '73.

Once you factor in the true curb weight and power loss to time/wear/poor tuning, I doubt that CL will ever outrun the TU. The juice isn't worth the squeeze.
Seems like you know this was a bad idea, why didn't you talk your dad out if buying that bike?
« Last Edit: May 25, 2021, 09:46:35 AM by Bluesmudge »

Offline mr72

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Re: I thought the GS was bad...
« Reply #4 on: May 25, 2021, 11:09:12 AM »
Well, I couldn't really come up with a reason why he shouldn't buy it.

I think the CL350 is likely making pretty much as much power as it did new in '72, maybe more, since it has free flowing exhaust and pod filters. My dad says it is a lot faster than the TUX. My guess is it has 50% more power than the TUX, maybe 20% more weight, but both bikes are also pushing my dad's weight.

I think 50% more power is meaningful. But yeah, I am beginning to regret not talking him out of buying it.

Offline chris900f

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Re: I thought the GS was bad...
« Reply #5 on: May 28, 2021, 06:28:48 PM »
CV carbs in 1972? I thought that CV's came later than that.... Well, I just deleted 3/4 of my post, 'cause they were indeed CV's with neoprene diaphragms!


If the bike is running ok it's probably just a matter of a gasket, or the needle/seat valve...(first part I ever replaced on a motorcycle) they wear out and are easy to replace.

It's too bad that the exhaust was replaced, those old scrambler high exhausts are gorgeous.
« Last Edit: May 28, 2021, 11:53:16 PM by chris900f »

Offline mr72

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Re: I thought the GS was bad...
« Reply #6 on: May 29, 2021, 04:49:39 AM »
he probably will bring it over today for me to look at if the rain holds off long enough. I agree it's most likely float needles and seats.

It has the original headers but has what look like emgo mufflers. They're loud.

Offline mr72

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Re: I thought the GS was bad...
« Reply #7 on: July 06, 2021, 02:41:03 PM »
FYI -- update

We did rebuild the carbs on this bike a few weeks ago. I gave it a test ride and it ran just fine. Hard to really know for sure though because I didn't ride it very fast, just up to maybe 35mph in the neighborhood. But it'll probably wheelie if you really want to.

My dad says on a long ride if you get to mid-rpm, light throttle steady cruise it kind of runs bad, surges or does other odd things. He's thinking it's the points ignition out of adjustment. That's over my head. Before my time. I even switched my 240Z to electronic ignition back in the day.

 

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