Had exactly the same bike, same colour too, brand spanking new . Ordered the week after Easter and delivered to the dealers 10 days later EXACTLY 46 years ago yesterday. Friday 12 April 1978. I loved that bike to bits.

you have figured this out by now but to the viewers, its a vaccum operated pedcock, prime is only to pre fill the carburators before starting.

I just bought the exact same bike. Mine has about a 1/4 of the miles and was garage kept so a little different situation but your video is great! Thank you for the inspiration!

@Turtles_Hotrods

23 күн бұрын

Awesome to hear. Check out what mine looks like now! She’s a whole lot meaner now. Haha

These bikes are among the toughest 4 ,s ever built .roller bearing crank , beast oil pumps , fat cases .the 77 with spokes is collectible .mine was eventually turbo charged , then a 1000cc GS engine , then a 1074,

I had one just like it 30 yrs ago... They are fun and pretty powerful for back then

Like the look of that Harley. Good video. Have not seen the use of diesel for cleaning parts for years. I always used it before

@Turtles_Hotrods

5 ай бұрын

That Harley is my baby. Can’t wait till it warms up a little so I can ride again

Good job 👍 I just finished mine 1978 Gs 750 and it's a beauty. Tuning the carbs was the most difficult part out of all, because you need every cylinder to reach the same temperature. Once you set your air/fuel mix right, it runs smoothly as it should. Hope you keep up and ride it.

@Turtles_Hotrods

5 ай бұрын

Oh yea I’m gonna do a full build series on it. She will be a beast when I’m done

Good video! Looking forward to the next one. One caution....once I fried a wiring harness on an old bike, by using jumper cables from a car that was running. Had to replace the whole thing. From what I've read and my own experience, you can jump from a car battery, but never have the car running....it's just too much power coming in from the car alternator. Obviously you did it successfully, but again, just a caution from one wrench turner to another. Also, I learned from working on old Japanese bikes, they really need that battery in there to keep running right....the stator just doesn't produce enough power, especially at idle, but good news is stator seems to be working well. Great job and looking forward to seeing this one going down the road!

@Turtles_Hotrods

5 ай бұрын

I’ll keep that in mind lol

It's only running on 3 cylinders - that popping is from the 4th cylinder trying to fire.

@Turtles_Hotrods

5 ай бұрын

Check out my short video titled “free horsepower” I took the mufflers off. The 4th cylinder has something wrong with it. But it’s definately firing. I read the plugs and 3 was lean the rest were fat but your comment earlier about the vacuum petcock made me realize I didn’t hook up any vacuum lines as they were all hard as a rock. So I’ll dial in the engine later with vacuum lines hooked up. That should help lol.

What you have there is a vacuum controlled petcock. It is designed so that in the on position, no fuel flows until the engine builds vacuum - you probably noticed a vacuum line going to the petcock. On position works normally; it just has to have engine vacuum. P is for prime; if you run it out of gas, you can put it in this position and it is just on always. The only position left is a normal off position. The idea is that you can never have a fuel leak from the carbs in the on position with the engine off. These are great bikes and will run forever - this thing is just tired and needs carbs work and tuning.

@Turtles_Hotrods

5 ай бұрын

Oh cool thanks for the info. I do remember a line coming from the peacock I didn’t hook it up though. And the carbs are gonna come back off and get completely gone through. I just kinda slapped em together to see if it even ran before dumping some money into it. Thanks again.

@shaunhardie6077

5 ай бұрын

@@Turtles_Hotrods the vacuum line coming from the petcock needs to be attached to number 2 carb. Don't leave the petcock on "PRI" for too long as the fuel will leak into the engine, and you do not want that to happen.

nice video! i see a lot of crud coming out of the , maybe its a bit clogged :o

@Turtles_Hotrods

4 ай бұрын

Oh yea. Gonna rebuild them when the build is closer to being done.

@strubbleler

4 ай бұрын

Neat! im currently also a rebuild, but on a 2009 GS500F ! the engine is out, waiting for new head gaskets! i hope i can do the timing correctly! ( scary ) @@Turtles_Hotrods

I'm getting a 76 gs750 tmrw man im stoked I have two yamaha fzr's 1 is a 91 600 that's been turned into a street fighter and I have a 89 750

@Turtles_Hotrods

2 ай бұрын

Heck yea. Gonna be sweet. I love this one. Check out the latest video on it

17:47 don't jump a motorcycle off or any type of Small engine with the car or truck running. A vehicle alternator can send too much voltage to the motorcycle electrical system and you can damage stator.

@Turtles_Hotrods

5 ай бұрын

Thanks for the info

Nice work, I'm looking for one of these, as I want another 4 with a kick start. these GS's are very strong man, but man you've had it is sitting for 20 years, those carbs need a complete overhaul before putting them back on. This bike is only running on 3 cylinders because the carbs need a new set of jets throughout definitely mains and needle jets and emulsion tubes and new needles if you can get them all and you need to clean that air box, don't chuck it. If you put those atrocious k and n filters on you're just nuts, you looking at the inner carbs running rich and the outer carbs running weak and it'll run like a sack of crap. That air box is designed to give the carbs equal air pressure, so you will need it or a replacement. I love these though I've had 2 of the 650's in my time and they are just a great work horse, not particularly fast, but they plod and are comfortable and they just feel like a proper bike. I soooo want to get one now after watching this.

@Turtles_Hotrods

5 ай бұрын

Thanks for the info. Gonna tear the carbs down and give them a complete overhaul for sure. How come there’s no way to tune the carbs for aftermarket filters?

@iFunktion

5 ай бұрын

​@@Turtles_Hotrods It's down to the fluid dynamics of the air flow and thermodynamics. So basically, when designing a multicylinder engine, the goal is to get all for cylinders running in perfect synchronicity, when you can get the engine running on harmonics suddenly all the rattles stop and the performance of the engine becomes really smooth. To get this you need consistency of air flow through the carbs bearing in mind that the power and torque curve of an otto cycle engine is not linear in any way, but getting all the cylinders working in harmony is the best possible compromise. When manufactures design the engine, they look at how to get that consistent and the best way is to condition the air in a box with baffles inside it that balances the dynamics of the air flow. With those custom filters, that are basically open to the elements, as you ride down the road, the outside two air filters are constantly having a flow of cold air rushing past creating low pressure for those carb, but the inner two are sat in a hot air lock and are getting a completely different condition of air, it's hotter and it's static, so they will run completely differently and you will find that the engine won't smooth out and you will get pronounced flat spots. For a custom build where looks are more important then it's not a big issue, but if you are keeping the bike stock, go for usability and replace that air filter. Once you have all that, go get yourself a carb balancing kit, they are about 100 bucks and you can run the bike and tune each carb so they all read the same, then you will get a nice running bike with decent fuel consumption. Carb balancing is that cherry on the top for getting really satisfying performance and is oft neglected. I hope this helps

@iFunktion

5 ай бұрын

@@Turtles_Hotrods By the way, I was really impressed with your trick for getting it to fire with no carbs on, that was a real eye opener

@Turtles_Hotrods

5 ай бұрын

@@iFunktion lol I came up with that on the fly. And I’m gonna make a very custom cafe racer out of it. One off exhaust, seat, tail. And paint job of course. But your comment about outside carbs getting cold air and inside carbs being hot gave me an idea I simply must try. Im not gonna leave it stock. Thats just not my style. 😎. Thanks for all the info though. I love to learn.

@iFunktion

5 ай бұрын

@Turtles_Hotrods Ah, if you are going to cafe it, then that works out slightly different, if I were in your position, in that case, get yourself a whole set of main jets, then you can change them out to improve the running, on the whole, I think it works out that the inner carbs will need larger jets than the outer carbs, to help balance it out, but it's easy enough to do but be prepared to have the carbs on and off a few times. Personally, i would go with no carbs and just mesh on the mouth of the carbs and run then straight, if it's not an everyday run, then that will be fine, it just means that service times need to be strictly adhered to and never miss an oil change, and avoid synthetic oils as they are too efficient for old bike. I used to run semi synthetic in my fireblade, but not fully synthetic. Following you so I hope to see how this progresses :)

you would get a few quid for that airbox

@Turtles_Hotrods

5 ай бұрын

I haven’t thrown it out yet lol I’ll put it up on eBay

What did you soak the parts in?

@Turtles_Hotrods

5 ай бұрын

Diesel. It cleans a little bit but more than that it breaks loose stuck parts and lubricates things

@adams13f

5 ай бұрын

@@Turtles_Hotrods carburetor as well?

@Turtles_Hotrods

5 ай бұрын

@@adams13f yes

how much for the air box ??

@Turtles_Hotrods

5 ай бұрын

Idk haha. I’m gonna put it on eBay. What are they worth usually

Is it for sale? I’m local

@jasoncabo8737

5 ай бұрын

It probably needs the points cleaned . Try to cut 1/4 off the spark wires and reattach the boots . With age the copper that contacts the boots/spark plugs corrodes . Great project

@Turtles_Hotrods

5 ай бұрын

@@jasoncabo8737 whoa. Neat idea about cutting the wires.

@Turtles_Hotrods

5 ай бұрын

Not for sale yet! Till I’m done with it. Gonna do a complete build on the bike. Cafe racer. Butter yellow and brown.

@Turtles_Hotrods

5 ай бұрын

@@jasoncabo8737 next video on the bike will be all about getting it running perfect and fixing the brakes. And driving it.

If it rolls over it will run. I bought a 78 ga 750 for 20 bucks. Before the internet. I got. Motor carbs frame swingarm shocks. Week later get a call form my sister in-law i gave my little brother cheep good on gas kick around toyota. My sister know where your brother at he took my new car. I just gave him one drove the 130 mies found his ass made him take the car back. Then took his only ride away from him. As I'm leaving.one of the cousins married to a Greek family comes to my car. Says I've got your brother bike parts in the back of my truck. Im tossing them. I look its compleat front forks wheel instruments wheel off a 1985 gs 550e with the 16" front 18" rear. Put it on the 750 put gs 1000 tank found stock seat pan fun 300 total scavenged bike.