Reviving a Barn Find or Project Bike


Since we’ve all found ourselves with more time to spend in the garage, maybe you’ve found time to revive that “someday” project bike. In this How To, we’ll show you some of the things you need to do to revive a bike that’s been sitting for a while. The bike in question is my Honda CL450. We’re continuing to work through some issues resulting from its long slumber. You’ll need appropriate wrenches, solvents and oil, and it never hurts to have a shop manual to reference. Any parts needed can be sourced from a variety of our advertisers. Let’s get started with the battery. Unless you’ve periodically charged it, it’s going to be bad. Find out what type, size and voltage before you get started. You’ll need good voltage to test out the electrical system. My preference is sealed batteries, no chance of acid ruining hard to find chrome parts. — Keith Fellenstein

1. Find out what spark plugs you need and buy new ones. Buy extras too, the non-resistor plugs for these old bikes are getting hard to find. Get a small packet of anti-seize too. Looking at the old plugs can give you a clue to hidden engine or carburetion issues. Check to see that the plug caps are securely fitted to the wires, as loose ones will misfire at all the wrong times.

2. Fuel? Probably bad. If you added gas stabilizer before storing it might be OK, but even with that you’re better off with fresh gas. Disposing of the old gas is a problem, but often you can use that gas in lawn mowers if you mix it with fresh gas. If it’s not at all usable, check with your city or county to see if they have a hazardous waste recycling program.

3. Oil? British bikes are notorious for draining their oil tanks into the sump, known as wet sumping. When it happens to a stored bike, it bathes the crankshaft bearings in oil, probably sparing them from corrosion. The other thing that happens often is a leaky petcock combined with leaky carburetors. Gas ends up in the oil. The combination is a poor lubricant and overfills the sump. In any case, you’ll want to drain the old oil and fill with fresh oil of the proper grade.

4. Carburetors? Did you remember to turn off the petcock and run them dry? Great! If you used gas stabilizer but didn’t run them dry that’s second best. Worst is if you just parked the bike with the carburetors full, or if the leaky petcock kept them full to overflowing. Regardless, it’s a good idea to take them off and clean all the passages.

5. Wiring? Stored bikes attract rodents. Rodents love to nibble wires. Make sure the wiring is intact, you don’t want the smoke to get out. Rodents also love to store food in the airboxes and carburetor mouths, check those for nuts and seeds. I know this isn’t the Honda, but it was a good example of pack-rattery.

6. Points or electronic ignition? If points, clean them to make sure you’re getting a good circuit to the coils and good interruption of that circuit to fire the coils. If they’re not too dirty, a piece of card stock drawn through them can restore their function. Too dirty/corroded and you’ll have to file or emery them clean. Don’t forget to check the gap and static timing if you can. Most electronic ignitions won’t require anything other than a fresh battery.

7. If you don’t know when the fork oil was last changed, it’s a good idea to check and change that too. This one doesn’t look as bad as many I’ve seen, though it did come out faster than I anticipated as you can tell from this photo. This old Honda uses ATF for fork oil, but yours may use a specific weight of fork oil. Make sure you have the right stuff and amount on hand.

8. How old are the tires and what’s their condition? As they age, they get hard like old pencil erasers and won’t provide the traction you need. Dry rot is also a problem. See if you can locate the date stamp on the sidewall. These were made the 47th week of 2012, so 8 years old. Even though they were never used enough to wear off the mold sprues, they’re past their prime. Best to be sure with new rubber.

9. Be sure to check the chain, it may be worn out or rusted stiff. This one looks OK in the wear department and still has a good coating of chain lube so it’s not rusty either. I could barely get the link to lift off the sprocket. If you can see daylight between the sprocket and chain when doing this, it’s new chain time. If you’re considering replacing a standard chain with a ringed chain, make sure there is clearance for the wider chain. On this CL450, a ringed chain will foul the clutch mechanism.

10, Compression testing is a good idea, and gauges are relatively inexpensive. If the bike has sat for a long time it may show low compression that will improve once it has run a while. Don’t forget to hold the throttle wide open when testing. A shop manual will be useful to tell you what the correct measurement should be.

11. This improvement in compression with just a little oil squirted in the cylinder tells us the rings are worn or stuck in the grooves. It will run with the lowered compression shown above, but if you want maximum performance and minimal oil burning, this engine needs a refresh.

12. It’s always a good idea to check your cable ends. Nothing ruins a good ride like a parted cable. I’m using a commonly available tool that clamps around the ferrule and directs the lubricant down the cable.

13. If you don’t have that tool, you can use the old tried and true method of a baggie with the corner cut out, taped to the end of the cable. Add your preferred cable lubricant and let it drain down the cable.

14. It’s also a good idea to lubricate the barrel of the cable where it rotates in the lever. This Honda has a plastic-sleeved barrel so it is mostly self-lubricating, but many bikes just have metal on metal contact here and lubrication is a must. Stuck barrels here result in frayed and broken cables.

15.  It’s also important to check and lube the throttle cable or cables. Undo the fasteners holding the throttle grip in place and remove the cable barrel from the twist grip. Old wiring harnesses are probably stiff, so take your time. There’s usually a way to get things apart with no damage.

16. After sitting for so long, the grease applied to lube the throttle sleeve becomes sticky. Clean the handlebar end with mild solvent like isopropyl alcohol and apply a thin layer of fresh grease. Clean the inside of the twist grip, too.

17. After sitting for so long, the grease applied to lube the throttle sleeve becomes sticky. Clean the handlebar end with mild solvent like isopropyl alcohol and apply a thin layer of fresh grease. Clean the inside of the twist grip, too.

18.  Close inspection and a shop manual also showed that this clutch cable was incorrectly routed, which made the clutch pull harder than necessary. It was supposed to run between the carburetors. If you have doubts that the cables are run correctly, a shop manual can help. Alternatively, a Google image search can provide visual clues if the manual doesn’t.

19. These scrambler high pipes are unobtanium, and usually rusted out, so they’re worth a bit of effort to clean and protect. We’ll spray the rusty bits with this Permatex Rust Treatment. Start by scrubbing any oil off the surfaces with a good solvent. Use a stiff wire brush to remove any surface rust. It’s not necessary to wire brush down to clean metal, the Permatex treatment will turn the Iron Oxide into Iron Phosphate and seal it with a polymer clear coat.

20. Follow the directions on the can, spray three coats, with minimal time between coats, then let the final coat dry. Don’t forget new exhaust pipe sealing gaskets, the old ones will be compressed and probably leaky.

21. So now that you’ve done all the above, fresh gas, fresh oil, fresh battery, what’s next? Turn on the taps, make sure the gas stops flowing when the carbs are full, turn on the choke, turn on the key and either kickstart or press the start button and hope for the best. It may smoke a bit at first, hopefully clearing up almost immediately (2-strokes not included). There may be some water out of the tailpipe(s) as it warms up. Listen for any abnormal engine sounds and be prepared to shut down if necessary. Now that the engine runs and sounds normal, you can tend to the rest. Finish testing the electrical system beyond the ignition. Check the headlight, taillight, brake light and turn signals. Test and adjust the brakes and clutch. Clean and polish the shiny bits. Most importantly, get out and ride!

Published on Dec 11, 2020
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