My rebuild journey. (old title: Future owner - Help me identify this 650.)

Also. The front brake seems to be really stiff. Its not locked up but I can hardly compress the handle and Im pretty sure it doesnt compress the front brakes. I probably need to look into refurbing that.
 
Yes, the front MC and caliper usually need a refurbing as well. A complete disassembly and cleaning will do the trick many times, no new parts needed. They get all gunked up inside from dried up brake fluid. These are like 40 year old bikes. Everything on them needs some love, lol. The fact that so much can be saved and brought back from the brink of extinction is a testament to just how well they were built.
 
Ok
Cred to mr 5Twins ..impressing knowledge
A few thoughts ..
Floats -- these can be checked putting in a bowl of water to se if they float .
if OK
Then with some cleaning money is saved -- soft toothbrush ..+ the right chemical

Taking out plugs to clean idle circuit.
I did not even after 35 years knew they was there . I don't think I have seen any plugs to drill out and I have never adjusted any
Screws. There
My view is that things one can do can also go wrong . Haven't we all been there .. Needing to exert force larger and larger hammers longer and longer pipe extensions on the wrench
and 5 minutes later are out on the internet googling after new parts. In the older days there could be a month waiting for parts
Depending on experience + skills and tools one can damage more than one repairs. Racking up large costs
These carburetors are more dirty than I have seen ..And it is a known problem running uneven so the ( small ) jets and Idle Circuits must be serviced
But I put it out here .. Is it really necessary to drill out anything. Personally I would hesitate doing it.
Cant it be done with cleaning fluid and compressed air..Just putting it out here as a Thought .
It might be necessary in this case but again if less risk with less work It can be an attractive action plan.
I admit that I am not Qualified when it comes to carburetors so I leave it to mr 5Twins and Grizid..




..
 
The plugs have to come out so you can remove the mix screws. As I mentioned earlier, you can't clean the idle circuit properly with the screw still in place, it partially blocks the outlet hole into the main bore. There's also a tiny o-ring on it so if you did try using carb cleaner, you'd probably just end up melting it. Besides, most need replacing due to their age. They're like hard rubber washers now instead of soft round profile o-rings. They're not doing their intended job of sealing the mix screw into the passageway anymore. But the biggest reason for removing the plug is so you can adjust the mix screw. The factory set it to meet emission standards, not for best running, and once you start changing jets, that will change where the screw needs to be set too.

Here's an old original mix screw (top) compared to a new aftermarket one. As you can see, the original o-ring is pretty badly flattened out and deformed (also hard as a rock) .....

LgzWvaD.jpg


And here's the mix screw outlet hole into the main bore. Pretty hard to properly clean that out with the screw in the way .....

lx1NNvl.jpg
 
The plugs have to come out so you can remove the mix screws. As I mentioned earlier, you can't clean the idle circuit properly with the screw still in place, it partially blocks the outlet hole into the main bore. There's also a tiny o-ring on it so if you did try using carb cleaner, you'd probably just end up melting it. Besides, most need replacing due to their age. They're like hard rubber washers now instead of soft round profile o-rings. They're not doing their intended job of sealing the mix screw into the passageway anymore. But the biggest reason for removing the plug is so you can adjust the mix screw. The factory set it to meet emission standards, not for best running, and once you start changing jets, that will change where the screw needs to be set too.

Here's an old original mix screw (top) compared to a new aftermarket one. As you can see, the original o-ring is pretty badly flattened out and deformed (also hard as a rock) .....

LgzWvaD.jpg


And here's the mix screw outlet hole into the main bore. Pretty hard to properly clean that out with the screw in the way .....

lx1NNvl.jpg

I was able to get the tower jets out. But i cant seem to get the washers underneath it. Any tips?
PXL_20201211_211056878.jpg
 
Yes, it's one "assembly" for one carb, so order two. But I'm not sure why you're getting these? If you don't drill too deep when removing the plugs, the screw tops will remain good, like new. If you're doing it for the little o-ring, the size used is a 1mm x 3mm. You can just buy them separately somewhere.
 
Yes, it's one "assembly" for one carb, so order two. But I'm not sure why you're getting these? If you don't drill too deep when removing the plugs, the screw tops will remain good, like new. If you're doing it for the little o-ring, the size used is a 1mm x 3mm. You can just buy them separately somewhere.
Oh great to know! Yeah the spring and stuff looks good but I was going to replace for the sake of having new. So I will try to find the o-ring. Thanks for saving me some cash!.
 
What are your thoughts on removing all that corrosion? You'll also be relacing the wheel with new spokes. It could be pitted when you get it cleaned up.
I was thinking of replacing the spokes and trying to polish and put a new clear coat on the wheel and bits. Do you think it's too much work?

I figured I already had to respoke my current wheel if I stuck with it.
 
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Do you think it's too much work?.
That has to be up to you. What do you have a better supply of, time or money? What value do you place on learning these skills if you don’t already possess them? Also, that wheel may or may not look worse when you open the box than it does in the pictures.
 
That has to be up to you. What do you have a better supply of, time or money? What value do you place on learning these skills if you don’t already possess them? Also, that wheel may or may not look worse when you open the box than it does in the pictures.

I have more time than money. But I do value the idea of doing the work and saying I did it. Do you think 40 is a good price?
 
Just a thought: before you commit to a wheel that needs so much work, post a WTB message for an 18" diameter rear 36-spoke rim complete with axle and see what responses you get in a week or so. Whatever comes up, you still may have to pay a little more, replace spokes and do some polishing, but it might surface some options for you.
 
Found some 18" wheels for 40$ + shipping. Spokes are pretty rusty but it comes with a axle. Thoughts?
View attachment 180785 View attachment 180786

Hi Sudonate,
$20 per wheel & an axle + shipping looks like a total deal.
(To reduce the shipping cost, ask the seller to take the tires off if you don't want them, eh?)
You'll hafta dismantle the wheel to clean & polish the rim and hub & replace the spokes with stainless.
Keep the nastiest wheel untouched as a re-lacing pattern.
 
Keep in mind that this is an aluminum rim. Your original front is a chrome plated steel rim. From a handling point of view, they say it's best not to mis-match rim types because apparently aluminum rims flex differently, or a different amount, than steel ones. You may never even notice if you don't push the bike hard, but just be aware of it. But, I guess getting the actual hub is the important thing. You could always put a steel rim on it instead of that aluminum one. But that is going to add more to the total cost. Maybe it's best to hold out for a 16" steel wheel just like was originally on there.
 
Keep in mind that this is an aluminum rim. Your original front is a chrome plated steel rim. From a handling point of view, they say it's best not to mis-match rim types because apparently aluminum rims flex differently, or a different amount, than steel ones. You may never even notice if you don't push the bike hard, but just be aware of it. But, I guess getting the actual hub is the important thing. You could always put a steel rim on it instead of that aluminum one. But that is going to add more to the total cost. Maybe it's best to hold out for a 16" steel wheel just like was originally on there.

Interesting. Honestly my biggest concern is the larger aggressive sprocket on it. I with that, and the non stock brake and wheel needing work and respoked. I figured I would just revert to stock.
 
Friends,

Thanks so much for the help this far!. I just got notification that my carb rebuild kit will be here tonight instead of monday. Is there anything I need to know about all the jets? Im going to match up the needle washer placement to the old one. Do the other jets just go in hand tight and adjust later?
 
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