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Discussion Starter · #1 ·
A while back I got a cb550 tank off another member on here to replace the custom tank on my bike. the cb tank is much fatter and aesthetically i think it looks much better. Also the custom tank is so small only holding like 3 gallons.



With that said, the cb tank doesnt fit over the customs coils. originally i had planned on banging out the underside to make it fit. After some measuring I learned that the OEM coils are about 7.5 in in width(outside to outside across the frame) and about 5in long. I would have to make about 2 inches of room on each side of the cb tank to accomplish this. I'm somewhat apt to do body work, hammer and dolly, but idk how good the outcome could be stretching the inside of the tank out like that.



Now Im figuring that i should try to relocate the coils to a different place, but not knowing much about them, idk if the honda engineers put them there for a specific reason or what. Ive heard that coils need airflow and could potentially over heat, theres also the fact that the cables to the plugs are only so long.



From searching i found this link to another post where blindstitch just bought new coils that were smaller and relocated them below the frame (backbone).



Do you guys think this is the best option? They really dont cost very much and have the endorsement from good source. while writing this ive also just read another post where ebay coils were said to be good. SO i guess i answered my own question.



One other thing if anyone knows, does the orientation of the mounting matter? it seems they are always mounted horizontally but if they were vertical would they not work?



thanks for reading and any input u might give



nieds
 

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well i was going to give you the link to dons post (blindstich) but you are one of the few that take the time to look for your self which is good



but i dont see why they wouldnt work as long as they are grounded it should work and dont forget to add pics to your build thread
 

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At $14 they are a really cheap alternative. The reason why I put the coils under the backbone the way I did was because it was the only way that didn't interfere with cables or hoses. I also had to cut down the front tube that they are held to in order to fit the new tank. The alternative coils also have maybe an extra foot of wire making it easier to put anywhere you want.



If I didn't have an airbox I would have probably mounted them back there.
 

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At $14 they are a really cheap alternative. The reason why I put the coils under the backbone the way I did was because it was the only way that didn't interfere with cables or hoses. I also had to cut down the front tube that they are held to in order to fit the new tank. The alternative coils also have maybe an extra foot of wire making it easier to put anywhere you want.



If I didn't have an airbox I would have probably mounted them back there.
If you don't mind me asking, where did you get your new coils? I could use a new set for mine, as the old ones are getting kinda weak.
 

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Discussion Starter · #6 ·
"If I didn't have an airbox I would have probably mounted them back there."





huh, i didnt even think of this. thought for some reason that the coils had to be where they are or near it. idk why.



Im going to have to think this out some more. when i finish deciding exactly what i want to do i will be sure to take some pics. i had pod filters but put the air filter back on bc i wasnt ready to rejet yet, i just wanted to ride it. probably wont start any work untill it starts getting really cold, which in upstate new york is going to be soon.
 

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You have to remember that you're trying to understand what was though of 30 years ago. Coils were big. wires were short and that was probably one of the void places that they could use.
 

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Shame too, cos all that wasted space in the gas tank. How much more gas could you get in with a flat bottomed tank?? Frisco, anyone?
 

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If the wire is replaceable on the coils you want to use, you could buy some Non-resistor wire from CarQuest or NAPA and mount the coils next to your tail light if you want.



Just make sure you have good connections on all the trigger and ground wires and you are good to go.
 

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If you brought it in to the same width as the GL tank, I bet you could get almost .5 gal.

 
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