1982 CM250 Custom parts

EzPete said:
Save the Seafoam. Regular motor oil, PB, WD40 all work.

Before you drain the tank, shake it around pretty good, wait a couple hours, shake it again, maybe repeat a few times. There’s going to be quite a bit of rust dust.
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I'd suppose it'd be good. I've let it soak 24 hours on some sides and over that on others. I might toss some old screws in there and shake the tar out of it though. Any tips on how to get all those flakes out the tank? Add baking soda water to rinse over and over?
 
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Be careful with screws - I've seen that poke holes in otherwise good tanks. I prefer bearings or nuts - if they're even needed. With Rust 9/11, it already has a neutralizer, so you don't have to get too crazy with the whole baking soda thing, just rinse well and dry thoroughly, then coat with oil. A magnet does a good job of grabbing loose rust flakes that evade the rinse - although for the most part they do rinse out.
 
The mesh on the built-in filter that runs up into the tank is broke in some areas. Wouldn't it be fine to discard it as long as I have and inline filter? The petcock filter is still in great condition.
 
You can limp it a long like that, but you’ll likely be cleaning the petcock out pretty often. That filter is a big first line of defense. Measure the diameter and length on that old filter. I’ve got a few extras from petcock experiments - may have one that’s compatible I can throw in the mail.
 
I was thinking of getting one of those mesh reusable inline ones and maybe fabricating the outer case to work in a tank. Mines about 1cm wide and 4 and 1/8" long.
 
What I did was get some extra fine stainless mesh to make a 'better' in tank filter.
Also found some electrical reinforcing stuff that was already in 'tube' form to fit over cables that was easier to use plus probably filtered better than the stainless?
I think it was for 'military' applications, tin or nickel plated wire of some sort, similar but much much finer than the plastic mesh stuff sold for harnesses or on computer power supply cables.
 
Finally! I got that tube out the carb. After grinding down a screwdriver for awhile, it worked! Now I may have another issue, the head of the tube is chewed up yet not all the way down. The holes running through it and down the center still had light coming through. Should I replace it? I’m guessing that now that the “stuckness” of it has been broken it’ll be easier to take out later if need be.1D66359E-335A-4D00-9447-871309928FB0.jpegF416A08B-814A-49E0-B064-83DB1099638E.jpegA0CDEE79-35E0-46BC-A9C7-4DD7E4FD3066.jpeg
 
You need to run a bunch of carb spray through the passage that jet was in, then blow it clear with air. Same with the jet itself.

The slot being chewed up is no big deal. Just clean the threads and it’ll be far easier to install and remove later for cleaning.
 
Ok. How far should I be running guitar string into the tiny holes near the throttle? I'm pulling out about an inch of string back out after stuffing it in. Does the piston need to re regreased, if so, with what?
 
That’s pretty good. They don’t go far. Blast them out with some carb spray and air after you do that and they should be clean and good to go.
 
The picture of you removing brass, small circle to right is block off plug for bypass drillings.
It isn't staked or glued in
Plug is about 6mm~10mm long, the drillings going through carb bore are in a very thin piece so you need to be very careful poking at them.
I wouldn't think wire can go in about an inch, it's probably going into drilling to pilot jet which means your approaching at a low angle?
There is a brass 'ball bearing' blocking the drilling if you look at carb 'end on'.
The nylon plugs on CB350 carbs can go brittle with age and go 'powdery' the alloy plugs I think are shrink fit?
You can remove them but need someone to make new ones, they are not a 'service part'
I have pulled them out on 360 carbs (drill tap 5mm mini slide hammer) but not knowing exactly what material they are I'm a bit wary of having too high expansion and cracking carb body.
Not sure if this will be any help but someone in future may need explanation?
 
Another question. Have y'all ever used any lead substitutes for gas? From what I remember, my bikes manual says to use either leaded or low-lead gas. I'd assume non-ethanol alone would be fine, but if it helps to use a lead substitute what do y'all suggest?
 
B.C. said:
Another question. Have y'all ever used any lead substitutes for gas? From what I remember, my bikes manual says to use either leaded or low-lead gas. I'd assume non-ethanol alone would be fine, but if it helps to use a lead substitute what do y'all suggest?
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I have purchased low lead aviation gasoline from a local air harbor. This was back when I was listening to people saying what the hot setup was for fuel on our 175 race bikes. One guy said mix 50/50 the 110 LL with ethanol free fuel, which seemed reasonable. I didn't notice a difference in power. I think the lead has to do with valves, that is to say, valves in motorcycles manufactured when leaded gas was the thing, need this lead so their valve seats are not compromised, but I'm not sure.

I've never added any lead substitutes so can't advise there. I think non-ethanol gas is the way to go for...everything
 
Short answer. No, your bike is set up for regular gas. Non-ethanol is the best for fuel systems if you can find it.
 
Honda's haven't needed leaded fuel since late 60's, (when they designed new motors for 65~66 model years)
Honda were often decades ahead of even future legislation proposed for late 70's, probably why 'all' the motorcycle designers moved to automotive in 77 and 78 models were mostly over engineered but under developed (basically pretty crap until 1980)
I'm thinking you read something wrong or misinterpreted?
If you want it for something else, various vintage car magazines did tests in Britain in the late 80's/early 90's (I had a 1965 Rover car at the time)
Switching to unleaded on a motor that needed lead resulted in exhaust valves sinking into head over 0.100" in 10,000 miles.
Back then, some sort of tin additive was best but I would hope there is newer better stuff by now?
 
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