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Discussion Starter · #1 ·
Hey guys, just got my first motorcycle, a '78 CX500 that's been in a barn apparently since '89.

Gave the metal a spray down with GUNK and pressure washed it to see what I was working with and overall it seems ok, but there are some things that definitely need looked at before trying to start it up.

The 'plan' is to get the bike started and see how it runs, just in case the engine needs work or not. Hoping to run it a month, see what needs done, then come winter dismantle to the frame and do a sorta cafe racer half-breed. Just looking for some advice to get me started.

1) Carbs need cleaned, no worries there, lots of straight forward YouTube videos for that. Was trying to find the pail of GUNK with the strainer bucket inside to give the parts a good soak but, hard to find in Canada. Anyone know where I can get that? As well, is it safe submerge the entire carb for a day then dismantle and clean? or would it mess up gaskets and non-metal parts? Or being unused for 25yrs should I simply splurge and buy the rebuild kit online when I buy new stainless steel Allen/Hex bolts?

2) Tank. Turned it over, and the gas came out like cooking oil. Tank itself seems to have very minimal rust. I wanted to buy the 3 stage kits for cleaning/derusting/epoxy coating the tank but not found locally... I'm in a bit of a remote area so, bit of a pain. May end up ordering online and waiting 2-3 weeks, use a water bottle with gas in the meanwhile for starting the bike. Was looking at paint thinners to remove sludge, but, varsol? mineral spirits? methyl hydrate? just use GUNK engine cleaner? dish soap and water? Rust wise, molasses/water works well on rust, maybe just use CLR... read something about Navel Jelly (?) last night that seems good... then pressure wash it all out and slosh about some isopropyl alcohol and dump it, help make it dry faster. It's the flash rust I worry about which is why I wanted the kit to epoxy coat it.

3) Engine. The fuel line was cut, but I don't know if it was cut before/after someone tried to start it with that thick old gas in the tank. I want to flush the system out if possible without the bike running yet. Something tells me if that gas is in the engine it may do more harm than good if I don't get it out first. Read some good things about Seafoam which I can buy locally, but how-to's are all on running bikes/cars. I know for cars they basically shoot a pressurized detergent/steam through the engine but I don't have that equipment. Any ideas? I don't mind ripping the engine apart... never done it before but I have the service manual and CX500 engine rebuild how-to... maybe (like the carbs) buy a rebuild kit and Allen/Hex bolts... but, would be nice to run it first if possible.

I'll also have pics posted soon. Going to do a blog/site of the whole start-to-finish of the bike. Figured it may help other newbies to see what I'm going through since I'm starting this project as a true beginner... so, hopefully I don't fail at it. :D
 

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Disassemble the carbs before dipping, the dip (if it's any good) will destroy rubber pieces. Also the dip will penetrate much better. The low speed jets are pressed in, can be removed with the right techniques, search for that info and/or use Larry's book. Complete carb clean must be with these jets removed, it's a problem area. The real carb cleaner works pretty well, there are modern "safe" (read ineffective) formulas in abundance now. Only Professional/WARNING/WARNING kinds are strong. Newer method is ultrasonics/detergent/water methods, safer and still effective. Old dirty carbs are a common denominator in poor running, but cleaning them effectively often involves a learning curve for the average wrench turner like me.
 

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I bought an 80 model that had been sitting since the late 80s. The carbs were gunked. I ultrasonic cleaned them several times. The main jet that is pressed in was so badly corroded it was seized in the carb body. One broke which I was able to get out. The jets are obsolete as well. I bought 2 sets of spare carbs from ebay and one already had messed up jets where someone had messed with it and the other set were not any better than my originals. My advice is buy the mikuni conversion set up from Murray. I am rebuilding the entire bike now but I have a set of his carbs ready to go on. Buying original carbs as spares and the costs of other parts hit close to half the price of the mikuni kit. Imo ditch the crappy keihins if you are positive the rest of the bike is good.
 

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Discussion Starter · #4 ·
I don't really have the cash for new carbs... no idea who Murray is either. :D

For the $35 after shipping I think I'll buy the carb kit since thinking after 25yrs sitting the rubber can't be very good anymore anyways. Kit is the one below, as well, buying the stainless hex/allen bolts. Saw a few posts saying it was a good idea to switch to the newer bolts. Then use GUNK brand carb cleaner which I hope is good (?).

Hopefully it makes sense to do that... just hate to take them off, apart, clean, assemble, then find they don't work right and then take them off, apart, then wait 2-3 weeks for the kit to show up. :S

Any advice for #2 and #3?

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Hey man, I just finished cleaning my carbs from my 81. I used Goo-Gone on some of the really bad areas. Also, I put a few drops through each jet (removed) to penetrate. And I used Dawn dish soap with HOT water when I was ultra-sonic'n my carbs.
 

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Any advice for #2 and #3?
#2:
The best way is to use an tank sealer for lightly rusted tanks.
The cheapest thing is to clean inside as good it works and to install an inline filter between petcock and carbs.

#3.
Drain the old oil. Change the oil filter, don't lose the spring and the big washer. Mount it on the correct way ;-))
Fill in the right amount of oil, run the bike for 50-100 kilometres and again change filter and oil.

Without warranty: You could pull the cylinder head covers, open the inspection plug/cover under the right side carb, fill diesel/gasoline in to a 100-200 ml syringe and press the diesel into the inspection cover. To press (with pressure of the syringe) gas/diesel into the cylinder heads You should it do, where the rods go into this tunnel going to the cam shaft.
During this cleaning the oil filter and drain plug must stay removed and don't turn the crank with the starter.

Gruesse
WolFgang
 

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Since you are just soaking the carbs, use a fine wire to "floss" the passages and to poke through the jet orifices to ensure that they are clear.
A single strand of telephone wire or Cat 5 wire works great for this.
 

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Discussion Starter · #8 ·
Oh not just soaking... cleaning is where my OCD kicks in. :D

Just figured let it soak a day, that way when dismantled it would be easier to clean everything.

I grabbed one of those carb jet cleaner tools off eBay which will hopefully help. Really wish someone locally sold those buckets of GUNK cleaner that has the parts basket. Saw it online but checking around no one seems to carry it. Would a general parts cleaner work for the bulk and a can of spray carb cleaner for the remainder? Always concerned when I do this stuff in case I grab a solvent and use it then everyone says 'oh no, you shouldn't have used that, it really messes things up'. :D

Last night I ordered the two previously mentioned kits for the carb rebuild and bolts, as well as the wire cleaner tool. Also grabbed WIX filters, new fuel line, fuel filters, clamps... just the basics to hopefully start this thing.
 

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Oh not just soaking... cleaning is where my OCD kicks in. :D

Just figured let it soak a day, that way when dismantled it would be easier to clean everything.
Really wish someone locally sold those buckets of GUNK cleaner that has the parts basket. Saw it online but checking around no one seems to carry it. Would a general parts cleaner work for the bulk and a can of spray carb cleaner for the remainder? Always concerned when I do this stuff in case I grab a solvent and use it then everyone says 'oh no, you shouldn't have used that, it really messes things up'.
Why so hung up on GUNK? There's other products that are effective. "Original" Pine Sol being one of them. Just soak with a warm soak- (not a boil) and your carbs will come out sparkling clean. As with any cleanser, just don't keep it submerged for too long. A hot plate would be ideal for this.
 

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Discussion Starter · #10 ·
Not really hung up on gunk, just the only name brand carb cleaner I can easily get my hands on, and quicker to type gunk than 'carburetor cleaner'. :)

Pine Sol though? Definitely smells better. Having never cleaned carbs before, not really sure what to expect in terms of how caked on the grime is.
 

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You don't mean one of these abortions, do you? Motorcycle ATV Carb Carburetor JET Cleaner Cleaning Smooth Wires SET Tools | eBay I don't know where anyone got the idea to sell welding torch nozzle cleaners for use on carb jets but I imagine there are a lot more screwed up jets since they started.

NEVER EVER put anything harder than the brass that a jet is made of into a jet unless you intend to drill it out to a larger size. Even a tiny scratch can change the way a jet works.

And unless you have the skills & knowledge to do it right, don't expect that getting a 36 year old bike into safe condition to use again will be cheap. You should replace every bit of rubber on it, inside & out and probably most of the gaskets. And as for the cheap carb kits, read this View topic - Carb Kits - A Comparison ? NGW Club and then buy quality parts like the ones Randakk sells.
 

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Discussion Starter · #12 ·
Yup... One of those abortions. Saw way more positive reviews on various sites than negative so figured can't be too bad. I'll be careful though because as you mentioned, the parts are brass. Probably use an old toothbrush for most, which the bristles will probably get into the holes.

Kit wise I got a basic one off eBay. Read posts where people said they were fine, others saying they suck, and others still that say why bother wasting your money get mikuni carbs instead. I don't expect to get the bike running cheap, but, I don't think I need to buy the most expensive parts either. I understand there are differences in quality for parts, not sure about stuff like gaskets and orings though.

May even be made in the same factory, like I just discovered WIX and NapaGold filters are, though the WIX are much cheaper. :)

That being said, just want it to run and drive around the yard, see if runs OK first before I dump money into modifications. No point blowing hundreds on just the carbs to discover the engine is 100% dead and the drive shaft is seized.

Skill wise, it's new territory for me, but not worried. I knew zilch about cars 5yrs ago, since then I've rebuilt half of mine. So long as I have Google and a good forum, I'm sure it'll get done. :)
 
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FWIW, I did my carb clean. I used some dip from WalMart....I think it is called Berryman's. I also used about 4 cans of spray carb cleaner.

The best thing I bought was the carb kit from Randaaks. It was about $100 USD, but it had all the bits and pieces for a complete build. The O-rings are made of Viton material. This is a much better material for exposure to gasoline than Buna-N. Be aware, many times the "cheap" sets use a low grade Buna-N. The next best purchase was Larry's book about cleaning these carbs. There is a link somewhere on the forum. I'm sure someone will provide. The book was about $25 USD. It is a step by step how to.
 

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Why so hung up on GUNK? There's other products that are effective. "Original" Pine Sol being one of them. Just soak with a warm soak- (not a boil) and your carbs will come out sparkling clean. As with any cleanser, just don't keep it submerged for too long. A hot plate would be ideal for this.
Not really hung up on gunk, just the only name brand carb cleaner I can easily get my hands on, and quicker to type gunk than 'carburetor cleaner'. :)

Pine Sol though? Definitely smells better. Having never cleaned carbs before, not really sure what to expect in terms of how caked on the grime is.
Simple Green also works well for this too and is not caustic.
 

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Discussion Starter · #15 ·
Good to know... Canadian Tire carries that, the Heavy Duty 4litre jug... I'll always take the green products over the environmentally unsafe ones, so may give that a shot.

I assumed that since there was stuff specific to carbs, that the stuff inside the carbs was so stuck on you'd need something really strong. Simple Green, Pine Sol... thinking dish soap would probably work. :D
 

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Discussion Starter · #17 ·
Ha... which loops me straight back to my original idea of playing it safe and buying something that says 'carb cleaner' on the label. :D
 

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i soak everything in SImple Green, then wipe and scrub where needed. If it's really bad, I use brake cleaner. Believe it or not, just a hose with water or air really blast out the crud effectively.

I like the suggestion of Pine Sol. I think I'll give that a shot someday. I'm all about saving money where I can.
 

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Simple Green also works well for this too and is not caustic.
Be careful using the Simple Green or so I'm told. This guy claimed he used it and ruined the finish on his carbs. I myself heard it works well which leads me to believe this guy probably left his carbs sitting in the solution for too long of period: Simple Green and my poor carburetor
 
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