Here are some recommended maintenance items you can address while you are awaiting the return of your rebuilt carbs. Most of this is written from the GL1000 perspective, but generally applies to other models as well.
Imperative – all tune-up issues must be in order before you synchronize your freshly serviced carbs. Especially: plugs, plug wires, points and timing! Click here for my “Tech Tips” section for helpful information on setting points and ignition timing properly.
1. Fuel Tank:
When your carbs arrive, they will have absolutely pristine innards. IT WOULD BE A CRIME to connect them to a contaminated fuel tank. Now’s the time to evaluate the condition of your fuel tank. At a minimum, drain all the old fuel out and replace with at least 2 gallons of fresh fuel (regular unleaded is recommended). The drain plug is located near the rear master cylinder. Obviously, do this outdoors to avoid fire hazard. Once the fuel is out, you can see the inside through the filler next with a strong flashlight (somewhat easier in a dark garage, so you may want to push the bike back indoors for this step).
If your tank is rusty, bite the bullet and remove for cleaning and re-furb. This is a bear of a job..very time consuming. Consult your manual for complete details. Generally, on a GL1000 – you will have to remove the following from the bike (other bikes have simiar procedures…consult your manual):
- Rear Shocks
- Rear Wheel
- Rear Fender
- Rear Inner Fender
- Rear Master Cylinder
- Final Drive Unit (“Pumpkin”)
You will also have to remove the 4 bolts which secure the top shelter (false tank). This is because the rear of the top shelter has to be raised slightly to allow the tank filler neck to slide to the rear.
Some manuals erroneously indicate that the swingarm and muffler have to be removed…this is not correct!
Since new fuel tanks cost $1000+ from Honda, rehabilitating your old tank is an economic necessity. Good commercial cleaning / protection products include:
Rustol from Sudco: https://www.sudco.com
MOTORCYCLE TANK REPAIR from POR: https://www.por15.com/FUEL-TANK-REPAIR-KIT/productinfo/FTRK/
GAS TANK SEALER FOR MOTORCYCLES from Eastwood: https://www.eastwoodco.com
KREEM: available at any motorcycle shop (not my favorite…a challenge to prevent clogging of fuel pick-ups) See this special precaution regarding the use of Kreem: click here.
Follow product directions to the letter. I recommend blocking the fuel pick-up lines with lengths of insulated wire inserted after you remove the petcock. Make sure the product does not block the fuel inlet screens as it sets up.
Also, many good radiator shops are set up to service fuel tanks at reasonable cost. One good one is:
Elizabeth Radiator Shop
1550 Hayden Boulevard
Elizabeth, PA 15037
Some folks recommend cleaning rusty tanks with diluted muriatic acid (generally 1 part acid to 8 parts water). A full tank of this solution soaked overnight will definitely remove most surface rust. After the acid solution is drained, you flush with water then add alcohol to dry the inside of the tank. Some recommend blowing air through the tank with a shop vac to ensure thorough drying (may take several hours for complete drying).
However, I don’t recommend this procedure as muriatic acid is a very hazardous substance. Also, it’s easy to remove more than rust and create holes which didn’t exist before (don’t ask!) Finally, it’s next to impossible to prevent a “flash” of rust from reappearing after you’ve cleaned the tank. Some recommend sloshing kerosene or 2 stroke premix to stop the rust “flash” but my results haven’t been great. My advice: go with one of the commercial products listed above or send your tank out to an expert.
Finally, obtain and install a new rubber gasket for the fuel gauge sending unit before you reinstall your tank. These reliably leak when reused.
2. Battery Service:
A weak battery yields a weak spark. If your battery is over 2 years old, replacement is recommended. Make sure you follow the manufacturer’s recommendation for the initial charge procedure. Using a “Battery Tender” is a foolproof way to perform the initial charge. Otherwise, a 1 amp trickle charge for 18 hours is what you need. When charging is complete, top off with distilled water. Make sure you install and correctly route the new battery vent tube…don’t reuse the old one!
3. Cam Belts:
If these are due for replacement, now would be a good time. Consult you manual for details on how to do this. Don’t attempt if you’re not clear on how this is done. A slight mistake can be very expensive! Incorrect valve timing will wreck your engine by bending valves.
4. Spark Plugs:
I recommend NGK plugs in the standard heat range: D8EA. These are reliable, economical and have wide operational flexibility. If your bike won’t run well with these then you have other problems. These are available at any motorcycle shop. Avoid Splitfire plugs. In my experience they are built to a poor standard and prone to physical failures. Iridium plugs are spendy, but an excellent choice in my experience.
5. Spark Plug Caps:
If you have the original plug caps on your bike, they are probably due for replacement. OEM caps are pricey; however, NGK makes a perfect substitute. The NGK part# is XD05F. The only difference is the raised white NGK logo on the side. To make the plug retainer seals fit better, I usually grind off the NGK logos. You can buy GL1000 / GL1100 caps here.
6. Plug Wires / Coils:
If you have trouble installing your new plug caps (if they won’t screw in tight) you can try nipping off 1/2″ of the plug wire and try again. If this doesn’t help, your plug wires are toast and should be replaced. Unfortunately, the GL1000 plug wires are integrated with the coils as a sealed unit (other bikes have more replacement options).
Here are your options:
New OEM Honda coil assemblies (best solution).
Aftermarket generic duplicate of OEM coil assemblies. These are available from Cycle Recycle II: https://www.crc2onlinecatalog.com/Index_Main_Frame.htm These work fine, but you will have to make slight mods to the brackets and wiring harness at the coils (blade vs. pin connectors).
Aftermarket coils and wires (like Dyna or ACCEL). These work fine, but you will have to make slight mods to the brackets and wiring harness at the coils. These have higher output than stock but don’t have original appearance if that’s important to you. Not much cost savings over stock. On the plus side, you can now replace plug wires in the future without disturbing the coils.
7. New Air Filter:
I recommend OEM Honda air filters. Aftermarket filters are generally acceptable. However, I don’t generally recommend “performance” filters like K&N due to their tendence to disrupt optimal jetting calibrations.
8. Breaker Points / Ignition Timing:
Correct breaker point and timing function is critical to a sweet running GL1000 engine! Click here for my Tech Tip on Ignition Quirks…”Split-Timing” Technique for helpful information on setting the points correctly.
9. Wiring Harness Service:
Now would be a good time to service all the major plug connectors and cable ends on your wiring harness.
- Stator Plug
- Voltage Regulator Plug
- Rectifier Plug
- Reserve Lighting Unit Control Module Plug
- Reserve Lighting Unit Resister Plug
- Starter Relay to Main Harness Plug
- Condenser / Breaker Points plugs
- Ignition Switch to Main Harness Plug
- Starter Cable
- Negative Battery Cable to Frame Cable
- Positive Battery Cable to Starter Relay Cable
Separate the connector or cable, gently scrub with soft brass bristle brush, clean with contact cleaner, repeat until all corrosion is gone, apply dielectric grease then carefully reassemble. Make sure locking tab on the connector is securely engaged. Handle the connectors with extreme care. They are 25+ years old and very brittle!
Carb Install and Synchronization Instructions: Yes, you will need to synchronize the carbs once they are returned and reinstalled for optimal performance! Click here for the procedure.