1977 550

[Guest]

I figured this would better be posted here...

I recently bought a 1977 gs550 that runs for $500.
Well the last couple of days its been nice so I have went riding a few miles after work and know alot more about the bike.
What I have done so far...
Oil and oil filter change.
I had a misfire so I cleaned the spark plugs and "attempted " to change a wore out plug end wire. ( I say attempted because the ones I ordered seem wrong)
New plugs, haven't installed.
Premium gas, and stp fuel and injector cleaner.

What I now know....
I found a pinched fuel line from an inline filter to the petcock, adjusted and it stayed running.
I have backfires from the pipes due to either lack of gaskets or wrong bolts( I haven't really looked into this yet)
My rpms seem to stay around 5000 tops and I cant go above 60 mph.
Any suggestions are appreciated, I didn't take any photos today and plan to start with carbs, airbox wires and fuel lines. I also have no clue what compression is like in the cylinders. It fires right up and seems to run to well for any serious problems so I'm leaning to the fuel, fire, air as the issue. Also posting this here because I plan on rebuilding this motor this winter as much as I need, I can and cash allows.

Thanks, shooter

[Rich82GS750TZ]

See the Top 10 Newbie Mistakes thread linked in my a signature. Written by member Nessism, added to by many, appreciated by all who come here with a $500 bike that “runs”.

Welcome to the forum. You’re in the right place.

[6ixshooter]

Thanks for the info... the plug ends or resistors I got were ngk, but they were the waterproof hard ones. Not sure the part number rn. The plugs are autolite from o riley the ngk equivalent. I haven't gotten into the carbs yet but have been looking at kits online to rebuild.

https://photos.app.goo.gl/acts1YxTEc2yPcJX9

https://photos.app.goo.gl/75SVQu1pgaDcErkc8

https://photos.app.goo.gl/tTstQPmRehqhVBXe9

[6ixshooter]

Oh I should also mention that in the paperwork I got with this bike, it was saved from a scrapyard by the previous owner who then told me he fixed it for his kid, who was afraid to ride it. It sat in a barn for somewhere around 8 years before he sold it to me.

[Rich82GS750TZ]

I’d start with valve clearance adjustment and a complete carb clean/ rebuild including new orings from cycleorings.com. Tutorial is on BikeCliffs website. Download a factory service manual if you don’t have one, also on BikeCliffs Website. Link in my signature. So much good info and how-to’s on that site. If you’re still looking at carb “kits” after reading the Top 10 mistakes list, Re-read the top 10 Mistakes list. (Hint: #5)

Please create a signature with your bike year and model in it (minimum). Go to top of any forum page, go to Settings, then Edit Signature. This helps people tying to help you without Having to look to see if you may have written it in your first post.

After searching for solutions for problems, if you haven’t found an answer, start a new thread in the appropriate sub forum. Like if plug and wire related, start a thread in the Electrical forum. Be specific about the parts. I don’t know that anyone would be able to tell what you’re trying to do with what you wrote about the plugs and wires above. (Below? Depends how you read the forum- oldest first or newest first)

Tip on using the Search function on this site to get any meaningful results.
Always choose advanced
Always change to search Titles only, type your keyword(s), then Search.

[6ixshooter]

Sweet man thank's... I appreciate it, new to this website and bikes. I posted a week ago after buying but I didn't really ride it. Awsome and #5 for sure. I'm gonna take your word for gospel when resourcing parts.

[Rich82GS750TZ]

I’m just pointing out where to find the info. Among some of the absolute wizards on this site with the real knowledge and experience, I am but a newb as well. But I have been here long enough to have learned how to find answers, how and who to ask for help, how to post pictures. I’ve learned a lot about how to make my bike better than it’s ever been.

[6ixshooter]

So just a quick update. I did change plugs and the previous owner had the wrong ones in. Hopefully no damage was done.
With the appropriate spark plugs I have my power back, tho I couldn't quite catch my buddies v twin harley. I did back off at 70 mph.
I'm addicted for sure.

[steve murdoch]

Even as a new rider on a smaller bike the one thing you NEVER say is "i couldn't quite catch my buddies v twin harley".....could be grounds for GSResources dismissal.

[GalDemSuga]

So just a quick update. I did change plugs and the previous owner had the wrong ones in. Hopefully no damage was done.
With the appropriate spark plugs I have my power back, tho I couldn't quite catch my buddies v twin harley. I did back off at 70 mph.
I'm addicted for sure.

Try harder

[6ixshooter]

Lol I stayed with him at 60 mph, he took off on a straight away, I up shifted and was around 70 mph and backed off.
We continued riding together.
His 1200 v twin is quick but my gs still needs alot of work. It's still not quite running right. I'm pushing premium gas thru and carb cleaner before I take the carbs off.
It's in need of some exaust gaskets and I'm not sure if the throttle is off or just me, but it bogs down after about half or 3/4 so I'm aware I'm not at full potential.
Tomorrow is payday and my Bill's are paid. I'm ordering all 4 carb rebuild kits. Tires, and picking up an inline fuel filter, plus the exaust gaskets.
Another friend of mine that works at a Yamaha dealership said he would scope my jugs and run compression for me. I've noticed no leaks yet, I may not even open the lower end.

P.s. really considering the 650 top end swap, but for now a decent running bike will make me happy.

[sam000lee]

Not to beat a dead horse but hopefully by "rebuild kit" you just mean the O-ring kit for your bike from cycleorings.com. I just picked up 1977 GS550 that hadn't run since 1981. Did the following and now it's golden:


- Valve adjustment
- Complete carb clean - full disassembly, 24 hour dip for each carb and new O-rings (with original jets).
- Cleaned out the tank with vinegar, petcock rebuild, new gas line
- Oil change after warming the engine up
- New spark plugs

The bike runs great and the next thing on my list - that I'd add to yours - is checking the points. A bad condenser can make it so that anything greater than 1/2 throttle is useless.

[6ixshooter]

Awsome thanks for the info.
I haven't ordered the kits but I was looking at the ones from cycleorings.com
The first thing I did was oil and filter change, the only filter I could source local was the wix.
I changed the plugs and one obvious wire end but I bought the wrong ngk end so its rigged onto the plug. ( I know dont yell at me)
I'm absolutely scared of the points due to lack of experience. I'm no mechanic but have friends who can time it out.
The petcock has me confused because it has to be turned all the way right to stay running and straight up and down says on???
Also I found gas leaks and the line to the Petcock was "pinched".
I'm not at my house rn but can get pics tomorrow, also another newbish question... I have two cables from my throttle, one is not connected beneath the gas tank. I do have a picture of this but its probably not a huge help.
I have rust on my tailpipe and a hole on the left one so probably will replace down the line.
My main holdback is money and time. I work to much to be this poor lol. It may take time but I'm patient.
I started out wanting to completely rebuild this motor but now I'm kinda wanting to wait and see what the compression is like, I fear I may need a head gasket.
My Yamaha mechanic friend said lifter tick from the timing being off.
I apologize for my newbie questions and rambling lol but I really like this bike and would love to get it purring.

[6ixshooter]

https://photos.app.goo.gl/XSHBdDas7psd5ugr7

[6ixshooter]

I'm also a bit concerned about this...

https://photos.app.goo.gl/aPaDtZ5Z8cwk1iGt9

The plugs I took out.

https://photos.app.goo.gl/ArANFksnCHMSCueR6

The plugs I put in.

( I know I need a seat)