First build, '77 Yamaha XS750

I recently acquired a rusty old '77 XS750 on craigslist for 300. The PO had been riding it as recently as 3 weeks ago, and it started on the first shot, but she had some problems idling (had to feather the throttle a bit).


The plan is to turn this into a Cafe, but I haven't decided on much as of yet. I have next to no mechanical experience, but have decided this would be a great way to learn my way around a bike. I got some information from some of the good folks here in the cafe help forum, and have already started tearing her down a bit. Being new to this, its kinda difficult to figure out where to start. I've got a repair manual, and I'm trying to follow the information from the yamaha-triples forum in regards to what to do first. I've ordered what I need to change the oil and spark plugs... but, and excuse me if this is a completely noob question, if I'm looking to clean up and repaint the frame, shouldn't I do that afterward? Or should I try to get the basics done first, get her running smoothly then start tearing it down and cleaning her up? When you have something this beat, where do you normally start?

I guess my main concerns as of right now are that her tank is pretty rusty on the inside, and the idling issue. I've read that there are acids that will clean up the rust in a tank and sealants to keep it clean, so I'm planning on doing that as soon as I can. As far as the idling problem, my limited knowledge points me toward the carbs.

As far as what I've done so far, I took off the tank to check the petcocks (neither seem to be leaking but the left side petcock lever is broken and is a PITA to turn). I also figured the idiling issue was probably the carbs, so I removed them, assuming they would need some cleaning. While I was in there I took out the air box, since I plan on putting pods on. Heres what she looks like now:


Heres a few shots of the carbs:



I'll keep this updated as I try to work through all this. Any and all advice is greatly appreciated.

Man, I sure wish I could be that lucky to find a bike in that condition for that great price. They want too much money for bikes here in MN. Nice find.

Congrats on the bike! I would get the bike running well before you tear it down to the frame. I have stripped the bike down and altered a few wires on the harness and I'm having issues getting everything to function correctly. I've spent 2 weeks looking at wires and I'm ready to throw in the towel and start over with a new harness but I'm soooo close to getting it right I can't quit.

For the carbs; take them down completely one by one. This is very important since all of them are a little different and you want the right parts going with the right carbs. Don't forget about the butterfly shaft seals. They don't come with the rebuild kits and are necessary after all these years. Boil the carbs in a 50/50 mix of lemon juice and water. If you have an outdoor grill with sideburner...use it, or the women in the house will whine about it for days.

Take as many pics as you can when disassembling something. If you're like me and didn't plan on the project taking more than a couple of months; remembering where parts go is a real pain in the ass. Even the order of washers and other small things can be a big deal. Put all parts in ziplock bags and label them with a permanent marker. Put them in a safe place where the marker can not wear off. After sifting through the parts box too many times I had trouble reading some of the labels.

The "so you acquire a triple thread" is ok; but if you really want to learn the ins and outs of this bike be prepared to spend some quality on the triples site reading the various threads. Get familiar with the search and use it for anything that might pop into your head. There are very knowledgeable on there and you will need them from time to time. If you ask a basic question that has been covered a lot you may get the cold shoulder. If you have any other questions you can always count on me to help you along with most of the basic stuff. I've done it all except for an engine rebuild. I also have several links that cover just about every part you will need or I will know how to locate it.

Now rip that obese bike down and make it fast! It looks like you have a great platform to build on.

Don't use acid for your tank. There's an easier and less toxic way that uses electrolysis. It's like plating chrome, but in reverse. I have a CB360 that came with a horribly corroded tank and this did the trick:

http://www.altelco.net/~jacil/clay/motorcycle/KElecSetup.html

When it's clean and rinsed out, spray a lot of WD40 inside to keep it from re-rusting.

The advice from Juggernaut about photos is great. Take pics from all angles, zoom in, zoom out, as many as you can.

The sandwich bags and sharpie marker method is a MUST. It only takes 30 seconds now but will save hours later on.

Poke around on eBay and look for the genuine shop manual, not just a Clymer-type book. It's well worth the investment, partly because it'll have the correct wiring diagram, not a generic one.

If you're going to strip it down to the frame, start by spraying every nut, bolt and screw with WD40. It might take a day or two (or three) to get down to the frame, so having the fasteners "pre-loosened" will make it easier.

-Ace-

Painting the engine per jcole of the triples forum. He has THE most beautifully restored triple on the forum.

Here is jcole's engine detailing process copied without his permission. [] brackets are my added advice

-Remove the engine and seal off all inlets very carefully. [Removing the engine makes this whole process a lot easier, especially painting] They must be well sealed. I used corks and insulating tube bound around the ports etc.
-Then hang the engine outside. (Or in a garage where spraying water is ok)
-Then buy gunk degrease or degreaser made by swarfega or other similar.
-Use a scrubbing brush and paint brushes and spend ages degreasing.
-Then the important part: Use a pressure washer and blast the engine clean. *[I wish I had a pressure washer. Not totally necessary but will save a ton of time cleaning off all the fins and the recessed areas of the engine]
-Degrease then repeat pressure washing time and time again.
-I found that loads of dirt was baked on and it took loads of detailed examination and scratching with blunt screwdrivers etc in between all the fins etc.
-Keep going with the pressure washer until you can see that the engine is PERFECTLY clean.
*****Be obsessive about not getting greasy hands on the hanging clean engine. Even clean hands will stop the paint sticking.

-Buy 3 1 lire tins of PJ1 satin black spray paint. [I used duplicolor Semi-gloss black]
-Put a convection heater under the engine (its essential) [you can also opt to let the engine dry for at least a week. Baking at 200*F is recommended but not totally critical. You can also let the engine warm up then turn it off, heat is required to set up the paint]
-In rising warm air (not hot) start to put thin layers of paint onto the engine. This is important... Don't be impatient. Do a thin coat and wait 20 mins. for the next. [or else you need to wait 24 hours for the next coat maybe longer depending on the paint]
(By the way I had masked off some places like the shaft flange).
-So with thin coats and following the instructions on the tin, you'll get amazing - perfect Yamaha reproduction - results.
Good luck!
John in Scotland

Congratulations on the buy. Get those carbs rebuilt! Putting a little thought into what mods your going to make when it comes to the intake and exhasts will save you some time if you change the jetting when they are apart. 8)

Another XS750 build. Good luck and all the instructions listed here will help out tremendously.

Khaameleon take a look here it's a very helpful site. I would also go though it based off the link below. I hope you get it running well soon! Good luck!

http://www.yamaha-triples.org/forums/thread-view.asp?tid=1365&posts=25&highlight=acquired&highlightmode=1#M20340

Thanks for all the info guys. Blakester, that link has been recommended to me at least 10 times by now, but I appreciate you sharing it. Its good stuff and hopefully anyone else working on a XS triple looking through this thread will find it. That whole forum is chock full of valuable information.

So I had some time on my hands tonight and decided to dig in and start breaking down the carbs for cleaning. I decided to go the PineSol dip route for cleaning. I removed all the insides of each carb as per the manual, put each carb's hardware in its own baggie for cleaning and reassembly later, but left the 3 carbs together for the dip. I went with a 50/50 solution; 2 bottles of Pinesol, 2 parts water. Looks like many people on yamaha-triples did this with pretty amazing success.

I'll post after pics in a few days, but in the mean time, here are some snaps of my disgusting carbs after I broke them down.

This is what the float bowl looked like in the middle carb, after the gas was dumped out...


Looks like there was some rust/limescale type buildup on the middle and left side carbs. Hopefully that cleans up easily. I might opt to do a lemon juice boil (as juggernaut suggested) if it doesn't clean up with the PineSol.


Now just to let the solvent to do its work while I wait for the carb rebuild kits to arrive.

Looks like a mess. Hey don't forget to submerge you floats in something to make sure there are not pin wholes. I would leave them overnight or so. I thought mine were going after I stuck min in for around 10 minutes and found out about a week later that there was a small leak that didn't put out any bubbles when submerged in water. I got stuck where I was. You can look into boiling those in a water lemon juice mix if you want I hear it works wonders. But you will have to remove all of the rubber parts of course.


Also when you go to sync them I used the "$5 sync tool" (just google that) that I made. It works GREAT! Have fun out there I will be watching this thread. Good lock.

i'd love to have an old triple some day. especially one in running condition for $300.00. good luck with the carbs. i'm mechanical but have very little experience with small engine parts. first major thing i did with one of my bikes was clean and rebuild the carbs. it was a little daunting but as long as you take your time and take pic and you'll be fine.

So I finally got all the parts to overhaul the carbs in last night and set out to do the final nitty gritty cleaning/polishing and reassembly on them when I ran into a snag. I'm trying to get to the butterfly shaft seals on the carbs, but I can't figure out how to disassemble the shaft. The manual I have has no information on replacing these seals. On one side of the shaft there is a nut, but it has a small washer bent around it which is preventing me from loosening it. Am I supposed to just bend the washer back so I can loosen it?


Shitty cell pics:






Juggs, did you replace the seals on yours?

Yes, I gave them a full rebuild. You need a JIS screwdriver or at least a pozidrive screwdriver to remove the butterfly from each carb. Do a search for the seals on the triples site. You will need to bend the washer flat to remove the nut.

The butterflies can be a little difficult to remove. I suggest pliers wrapped with a paper towel or electrical tape to avoid gouging them.

Be sure to check the idle jets and look to see if the tips broke off inside of any of them.

any news on this build?

Watching this!