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Discussion Starter #1
Hi all. been watching the forum for awhile and you guys seem very knowledgeable about these old cb's so I decided to join.I bought a 72 cb450 a few weeks ago. a little bit of work and I had it running good.
,breaks,cleaned petcock,spark plugs. that's all I had to do.Drove it around for about 20 mins.It was parked for 2 days when I went back to it I couldn't get it to start. did some checking and I have no spark in one cylinder.I changed the spark plug and still no spark.I'm guessing points/coil/condensor but I don't know where to start. Any help is much appreciated.
 

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man, that thing is gorgeous. where'd you find it?

As for spark, I'd check the coil(s) - you can measure the impedance of the coil if you have the right tool - if it's off, the coil is bad. They're not that expensive, and you can probably replace the pair of them with coils of the proper impedance from any auto parts store. You can't replace just the wires on the stock coils, and if they're original a break in the wires is likely.
 

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Thanks for the compliments .The story is that the bike sat in the window of a motorcycle shop (advertisement) for 15 years or better it only has 8000 miles on it.
somewhere in N.C. Also thanks for the info if coils are reasonably priced I'll just go ahead and change them.They probably are stock.Any idea on what the proper impedance should be?
 

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Dido on the bike - nice looking. Re-check your points settings - it doesn't make any sense why it runs on day and dies after sitting for a few days.
 

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thanks. I don't have any feeler gauges yet so I'm not sure of the points settings. but I did take the cover off of the points and turned the motor over. and I did see spark on both sides. I will recheck when I get a gauge.
 

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Discussion Starter #7
ok so I check my points their ok and then I checked the plug wires looked good no cuts or breaks not even dried out checked the plug to wire connection looks good.
so I started looking for coils. Local honda shop can't get em. ok Ebay.Found a set on ebay and the same guy was selling raask rear sets and a bubble seat for a cb450.
Emailed him struck a deal. Now I have a set of coils on their way hope that fixes the spark problem.can't wait to caffeinate my bike.
 

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Shawn,
Did you charge the battery? Those Hondas have to have 12V to run. That is 12V under load. Stick a volt meter on the battery and turn the ignition on and see what you have. I doubt you coils went bad just sitting. Lots of people replace good coils but don't know it because when they unplugged the old ones and plugged the connections in for the new ones they cured the bad wiring connection that was the original cause of the problem.

Ken
 

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step 1: check battery - you need some voltage to be able to polarize the magnets in the stator, otherwise she don't run

step 2: check points, if there is a short in the igniton (or you accidently left it on) and one of the points was closed then it goes bad quick.

Step 3: check plug wires. These bikes are old, and honda plug wires can't be changed without changing the coil. Make sure your plug wires are making good contact.

Step 4: check connections to coil. Sometimes a loose or corroded wire will kill the whole deal.
 

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Discussion Starter #10
battery is 2 weeks old and has been hooked up to a trickle charger after each attempted starting session.will definitely check the wiring to the coil.Don't know why I didn't think of that. Thanks Ken
 

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Discussion Starter #14
So like I said I'm a newbie. Apparently my points weren't adjusted correctly. I adjusted them again, they might not be right, but it's better now because I have spark.
I haven't started the motor yet because I have the tank off.I'm gonna try to clean up the inside a little bit.Any suggestions on cleaning the tank? Or maybe a idiot proof guide to setting the points. I'm sure this has been covered but I'm not having any luck with the search. Seems like I came across someone using CLR? in the tank.Thanks for all the help guys
 

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I wouldn't bother lining that tank unless you've got some real shaky looking spots... I use Evap-O-Rust on all my rusty iron / steel because it is what's known as a chelator which bonds with the oxides in the iron and removes the rust without removing metal. CLR is an acid and while removing rust with also etch the good metal and remove good metal at that. You can leave Evap-O-Rust in for 100 years and you wont lose any steel. Best part is you can dump it down the drain with no worries as it's biodegradable and water soluble.

You can also use electrolysis to clean the inside of the tank, but I'm kinda lazy to set it up, so I go the evap-o-rust route. Either way you do it, once you get the rust out, clean it real good with super clean or simple green, rinse it out with deionized or distilled water, and run some "ospho" or phosphoric acid through it and dry it real good. then run some more distilled water through it, and then some denatured alcohol to try it, then a little spray of WD-40 to get any last bits of water and you should have nothing to worry about. If you want to use the sealer, do everything above but the WD-40 and make that step the sealer step instead. Proper metal preparation is CRUCIAL to the success of any sealing product, be it tank sealer or primer and paint. Skimp on prep you lose on end result.
 

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Please don't molest that beautiful survivor... do some research into the 450's. You may have a change of heart.

-Deek
 

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Discussion Starter #19
thanks for the tank cleaning info guys.Where can I get Evap-O-Rust? Never heard of it before. Also I'm not much of a purist. Yeah the bike is in great condition. I'm not gonna hack it up. My plan is to do some changes but keep all the original stuff so I can put it back on if I decide to.I'll start a project thread when I get some pieces together so you guys can give me advice/opinions.But in the end it is my bike. Unless someone wants to buy it to preserve it.It will be my cafe racer.Thanks for all the help.
 

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You can get Evap-o-rust at Oreilly's auto parts stores, Advance doesn't carry it, and I think Autozone has it as well, but Oreilly's is cheaper. Harbor Freight has it at extortionist prices. You can go to their website and do a dealer locator thingy as well. I swear by that stuff man it makes resto SO much easier my god... The main key is just make sure all your parts are clean and degreased. It will eat through as much rust as you throw at it. A trick that I use is since it's a chemical reaction, like most reactions, it works faster if it's hot. If you get a tupperware container, gladware, just some plastic container where you can fit your parts in totally subgmerged in it, pop it in the microwave till it's like hot coffee but not boiling, it works realllly fast. The evaporust will turn black like coffee when it is "spent". Your parts will have this black film on them which is an oxide layer that will scrub right off with water and a light brushing. After you do that it's good to do another round of degreasing. You'll see what I mean. You think you got everything clean until when you take the parts out of the evaporust there will be a few little spots that are stil rusty. This is because those spots most likely still have some oil or grease on them. Silicone grease is the worst to remove. I reccomend Talstrip or MArhyde metal prep spray or liquid for grease and wax removal prior to evaporust dunk. Anyway, once everything is totally degreased and derusted it will look like a brand new piece of metal. Get everything really dry. I like to stick shit in the oven for an hour or so at like 280 degrees. This will bake out the water as metal is porous. Kind of like the previous post with using alcohol. I stick tanks in the oven too, but if you're gonna do that make damn sure everything is out of the tank for obvious reasons hehe... Anyway, baking the metal opens up the pores and gets some more impurities out. You don't want to go much above 280 though because of possible distortion or tempering issues that come with high temps. After about an hour or so, or when you can't smell anything anymore (I baked a tank for 6 hours once...), just turn the oven off and your parts will be safe for a couple of days wihout rusting again generally, unless you live in a really humid climate.

I'm not intending this to be a painting tutorial though just an evaporust one. If you need help painting let me know, that's another novel :)

Good luck.
 
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