By Mike Grage, Tech and Customer Support at The Bonneville Shop and British Iron
When I started my career as a motorcycle technician after graduating MMI in 1991 I had no idea that every spring every shop I worked in would be filled with motorcycles that ran when they were parked anywhere from a few months to many years. Most of the time they were parked when the weather started to cool off in the fall.
For this series of blogs, I’m going to go over all the preliminary checks for a Hinckley Triumph barn find that sat so long I had to hit brake calipers with a dead blow hammer to push the brake pistons back far enough to roll it out of the dust infested abyss it was hidden away in for a decade or more. This first part is going to be how to start and tune the bike, however there are several other checks and repairs that need to be done before taking it for a ride.
First Things First
Once the motorcycle is in a place where it can be worked on the first thing to do is get the rear wheel off the ground with a jack similar to The Bonneville Shop part number TBS-37-9847. Remove the fuel tank and side covers and visually check the wiring harnesses for damage, mice and rats like chewing on wires for some reason. If the wire harnesses are damaged, they will need to be replaced or repaired before proceeding. If they are intact, get your service manual ready and keep going.
Spark Plugs
Now the spark plugs need to be removed. After that we need to make sure the engine rotates smoothly. For this we use the leverage of 6th gear. To get the bike into 6th rock the rear wheel back and forth while upshifting, no clutch is necessary with the engine off, and chances are the hydraulic clutch fluid is dried up. Once it is in 6th gear with the spark plugs removed, you should be able turn the engine over smoothly by turning the rear wheel. If it turns smoothly, reinstall the spark plugs, put it back in neutral and keep reading.
Oil
Next you will need to look at the oil level sight glass. If the oil level is higher than the sight glass you will need to pull the drain plug to get the oil down to the correct level, you can go ahead and change it at this point if you want to, but keep in mind we are still determining whether the bike will run or not at this point.
The reason why the oil needs to be drained to the proper level from the plug is because there may some gasoline or water that drained into the cylinders from the carbs and made its way past the rings and ended up in the bottom of the oil pan. Do not panic if clear water or gasoline comes out before any oil. Just let the non-oil liquid drain out until it’s down the proper level.
Did your Hinckley Triumph Barn Find Run When Parked?
Now we’re going to find out if your Hinckley Triumph barn find actually ran when parked in a quick and dirty way. You’ll need a can of carb cleaner, a charged battery, and make sure you have a fire extinguisher nearby just in case. Connect the battery and turn the key on and make sure the dash is lighting up and everything is working, give the starter one crank and then turn it off.
Remove the air filter and leave the airbox open. Put a 1-2 second spray of carb cleaner in the airbox, more than a 2 second spray might cause a backfire that will scare the neighbors, and someone might call the cops. Turn the key on and crank it over. The engine should fire up for a couple of seconds after a few cranks. Do not run the engine on carb cleaner for more than a few seconds. At least one cylinder will be very rough due to rust on the exhaust valves and the fact that carb cleaner is not the best fuel. Turn the key off and disconnect the battery.
If everything went as I described up until this point, your bike actually ran when parked.
This is when you need to change the oil and oil filter, then remove the spark plugs and give the motor a few cranks to put a fresh and clean coat of oil on all internal parts as soon as possible.
Tests for Your Hinckley Triumph Barn Find
If it did not start and sounded like it wanted to, check for spark. The first thing to test when there is no spark on one of these bikes is the handlebar kill switch. If the switch tests good and there is still no spark, proceed through the ignition diagnostic guide in the service manual.
A compression test should be performed to make sure it is within specification so it can be properly tuned, even if it ran on carb cleaner. There is a chance that one cylinder will be slightly low due to a dirty valve or two from sitting so long. This will right itself after the engine runs for a few minutes. The factory specifies compression test pressure of 100-175 psi. A reading under 130 psi normally requires a valve adjustment, or a carb may have a sticking slide. Anything under 100 is not a good sign will be expensive to fix.
Carb Cleaning
The first job to start if it passed the run test is the most tedious thing of all, carb cleaning/overhaul. The factory service manual has step by step instruction on how to fully disassemble the carbs. A pro-tip for cleaning the carbs is use a single strand of copper wire to make the air holes in the emulsion tube are clear. Same method through the primary jets.
The majority of the jets or gaskets that you may need are available from Modern British Iron, you can find them by clicking here. Using a remote fuel bottle to make sure fuel inlet pipes are not leaking is a very good idea, same method can be used perform the float level check in the manner suggested in the service manual. A pro-tip that is ignored in the service manual is making sure the transfer ports are clear. These are the four small holes in a diamond formation between idle mixture port and throttle butterfly. Clogged transfer ports cause stumbling off idle.
While the carburetor parts are soaking it would be a good time to check for sticking buckets/tappet and get it ready for a valve clearance check/adjustment. Remove the cam cover and sparks plugs, then rotate the motor over a few times using the back wheel with the transmission in 6th gear to make sure the tappets/buckets are moving smoothly.
A sticky bucket will require camshaft removal to clean the bucket and head, and possible bucket replacement. With no sticky buckets it is time to do the valve adjustment. The valve adjustment instructions and specifications are in the service manual. Modern British Iron offers a valve shim removal tool kit that is easier to use and is much more cost effective than the Triumph factory tool. We also have a full kit of 25mm shims and individual shims in stock and ready to ship.
Triumph Twins Triples K&L Adjustment Shims PN MBI-KLSHIMS
$14.29 – $14.85Price range: $14.29 through $14.85
Once the valve clearances are confirmed/adjusted, the carbs cleaned/reinstalled, new spark plugs installed, and fresh oil/filter we need to make sure the coolant is at the proper level because we are about to fire it up. You will need the remote/auxiliary fuel bottle previously mentioned and some carb sticks/manometers. The service manual provides some detailed instructions on how to adjust the idle mixture screws and synchronize the carburetors. Personally, I like to start with the mixture screws 2 turns out.
After the bike is started, at operating temperature, revving up smoothly, and running right we know the engine is confirmed good and we can start the rest of the cleaning process. The first item on the list is the fuel tank and petcock. Be sure to use a dental mirror and flashlight to check the top of the inside of the tank for rust. Rust means the tank will need to be relined. Hard epoxy fuel tank liners like Caswell are the best, and closest to what the factories use. I would highly recommend investing in a fuel petcock repair kit if the fuel tank is rusted, or if the gasoline in the tank has dried up.
In part 2 of this blog on a Hinckley Triumph barn find, we will go over the braking system and how to address stuck calipers and dried up brake fluid. Hydraulic clutches will also be included in the next installation.
Frequently Asked Questions
What should I do first with a barn find Hinckley Triumph?
Lift the rear wheel off the ground with a center jack like the K&L Center Jack (TBS-37-9847). Then remove the fuel tank and side covers and inspect the wiring harnesses for damage, because mice and rats like to chew on wires. A damaged harness must be repaired or replaced before you go any further. If the harnesses are intact, grab a service manual such as the Haynes workshop manual for 1991–2004 Triumph triples and fours and keep going. Wiring repair parts are in Electrical and Ignition.
How do I check if a motorcycle engine that’s been sitting is seized?
Remove the spark plugs and put the bike in 6th gear for leverage. With the engine off, you can rock the rear wheel back and forth while upshifting, without the clutch, which is lucky because the hydraulic clutch fluid has probably dried up. Then turn the rear wheel by hand. If the engine turns over smoothly, it isn’t seized. Reinstall the plugs, shift back to neutral and move on to the oil.
Why is there water or gasoline in my motorcycle’s oil after storage?
Gasoline or water can drain from the carbs into the cylinders, get past the rings and collect in the bottom of the oil pan. If the oil level is above the sight glass, remove the drain plug and drain down to the correct level. Don’t panic if clear water or gasoline comes out before any oil. Let the non-oil liquid drain out until the level is right.
How can I tell if a barn find motorcycle ran when it was parked?
Use a quick carb cleaner test. With a charged battery hooked up and a fire extinguisher nearby, turn the key on and confirm the dash lights up. Remove the air filter, give the open airbox a 1–2 second spray of carb cleaner, and crank the engine. It should fire for a couple of seconds after a few cranks. Spraying for more than 2 seconds can cause a loud backfire, and you shouldn’t run the engine on carb cleaner for more than a few seconds. Expect at least one cylinder to run rough, from rusty exhaust valves and because carb cleaner is a poor fuel. If it fires, the bike ran when parked.
What should I do right after a barn find motorcycle starts?
Turn the key off and disconnect the battery. Then change the oil and oil filter, remove the spark plugs and crank the engine a few times to coat every internal part with fresh, clean oil as soon as possible. Find oil service and engine parts in Engines and Engine Parts, and fresh plugs from NGK.
Why won’t my Hinckley Triumph start even though it’s trying to?
If it sounds like it wants to start but won’t fire, check for spark. On these bikes, the first thing to test when there’s no spark is the handlebar kill switch. If the switch tests good and there’s still no spark, work through the ignition diagnostic guide in the service manual. Testers and ignition parts are in Electrical Tools and Electrical and Ignition.
What compression should a Hinckley Triumph triple have?
Triumph specifies compression of 100–175 psi. Below 130 psi usually means the valves need adjusting, or a carb may have a sticking slide. Below 100 psi is a bad sign and will be expensive to fix. Do a compression test even if the engine ran on carb cleaner, so you know it can be tuned properly. One cylinder may read slightly low from a dirty valve or two after sitting so long, and that usually corrects itself after the engine runs for a few minutes. Compression testers and other diagnostic tools are in Engine Tools.
How do I clean carburetors on a barn find Triumph?
The factory service manual has step-by-step instructions for fully taking the carbs apart. Use a single strand of copper wire to clear the air holes in the emulsion tubes and the primary jets. Make sure the transfer ports are clear too; they’re the four small holes in a diamond pattern between the idle mixture port and the throttle butterfly. The service manual skips this, and clogged transfer ports cause stumbling off idle. A remote fuel bottle helps you check for leaking fuel inlet pipes and do the float level check. Jets and gaskets are in Carburetor and Fuel Delivery, and the full process is covered in the CV carb cleaning and tuning guide.
How do I check for sticking valve buckets (tappets) on a Hinckley Triumph?
While the carb parts soak, remove the cam cover and spark plugs, put the transmission in 6th gear, and turn the engine over a few times with the rear wheel. Make sure every bucket moves smoothly. A sticking bucket means removing the camshaft to clean the bucket and the head and possibly replacing the bucket. If none are sticking, go ahead with the valve clearance check and adjustment.
What tools do I need to adjust Hinckley Triumph valve clearances?
The adjustment procedure and specs are in the service manual. The Triumph valve shim removal tool (MBI-VSRT) is easier to use and costs much less than Triumph’s factory tool. For shims, buy individual K&L adjustment shims or the complete K&L 25 mm valve shim kit (VSK25). See more from K&L Supply.
How do I start and sync the carbs on a barn find Triumph after rebuilding them?
First, confirm the valve clearances are set, the carbs are cleaned and reinstalled, the new spark plugs are in, the oil and filter are fresh, and the coolant is at the right level. Then use a remote fuel bottle and carb sticks or manometers to adjust the idle mixture screws and synchronize the carbs, following the service manual. Mike likes to start with the mixture screws 2 turns out. Once the engine reaches operating temperature, revs smoothly and runs right, the engine is confirmed good.
How do I know if a motorcycle gas tank needs a liner?
Use a dental mirror and a flashlight to check the top inside of the tank for rust. Any rust means the tank needs relining. Hard epoxy liners like Caswell epoxy gas tank sealer work best and are the closest to what the factories use. If the tank is rusty or the gas inside has dried up, Mike also recommends a K&L fuel petcock repair kit for carbureted Triumphs (MBI-182842). The series continues with Part 2: Triumph hydraulic brake restoration and Part 3: Hinckley Triumph maintenance and restoration. For factory maintenance schedules, see the Triumph owner’s handbook library.
