Dirt Bike Overheating on a 2018 Honda CRF110F - Causes and Fixes
Shop parts for a 2018 Honda CRF110F Dirt Bike.
Why your CRF110F might run hot normal vs. problematic temperature rises
The 2018 Honda CRF110F is a compact 110cc youth trail/motocross machine built around an aircooled, smallbore engine. Because it relies on airflow over cooling fins rather than a liquid system, the bike will feel hotter to the touch faster than a radiatorcooled machine. Short bursts of elevated temperature during slow technical riding, hill climbs, or heavy throttle use are often normal for this class of bike. Persistent high heat, loss of power, smoking oil, or repeated stalls indicate an underlying mechanical problem that needs diagnosis.
Primary causes of dirt bike overheating on the CRF110F
- Poor airflow to the cylinder & fins - Mud, packed dirt, or a blocked shroud reduces convection cooling. Riding with altered plastics or storage racks that block air paths has the same effect.
- Dirty or restrictive air filter - A clogged filter leans the intake or causes excessive intake restriction that forces the engine to work harder and run hotter.
- Low or degraded engine oil - Oil lubricates and removes heat. Low level, wrong viscosity, or very old oil increases friction and temperature.
- Lean fuel mixture or carburetor issues - Lean jetting, clogged pilot jets, or a sticking float needle raise combustion temperatures and can produce detonationlike symptoms.
- Valve clearance out of spec - Excessive valve clearance or valves seating poorly leads to hot running and reduced cooling efficiency from poor combustion sealing.
- Ignition timing or spark plug problems - A fouled, worn, or incorrectheatrange plug or advanced timing can create higher combustion temps.
- Compression changes or internal wear - Worn rings, scored cylinder walls, or head gasket issues reduce efficiency and raise operating temperature over time.
- Prolonged idle or slow technical riding - Low vehicle speed reduces airflow over the fins, causing steady temperature climb during long idling or tight courses.
Inspection steps you can do at the trailhead or in the garage
- Visual check of cooling fins remove loose debris, packed mud, or grass from around the cylinder head & fins. Use a brush and compressed air if available.
- Air filter inspection take the filter out, check for dirt saturation, damage, or oil clumping. Clean or replace as needed.
- Oil level & condition warm the bike, check the sight glass/level, and verify oil looks clean. Top up with the correct viscosity as required.
- Spark plug check remove the plug, inspect the color and gap. Replace if fouled, damaged, or the heat range seems incorrect.
- Carburetor basics verify choke operation, ensure the float bowl is tight, and look for obvious fuel delivery problems or leaks.
- Exhaust and intake leaks listen for unusual noises, inspect manifold bolts & intake boot for leaks that could lean the mixture.
Troubleshooting common causes practical fixes
- Blocked fins or shrouds - Clean thoroughly. Remove side panels if needed to access fins. For caked mud, soak and gently scrape; avoid bending fins. Reinstall panels to their stock positions for best airflow.
- Restricted air filter - Replace a paper filter or clean & reoil a foam element. Never ride with a dry foam element that needs oiling, and keep a spare filter on longer outings.
- Oil service - Change oil and filter if dark, gritty, or overdue. Use the recommended weight for the CRF110F and verify correct fill level. Fresh oil improves heat transfer and reduces friction.
- Carburetor tuning - If running lean, enrich the mixture slightly via the pilot screw or main jet within safe limits for this engine. Clean clogged jets and passages. A properly tuned carb reduces combustion temps and improves throttle response.
- Valve clearance adjustment - Check and adjust clearances per simple feeler gauge procedures if you have the tools and basic skill. Tight or loose valves can be corrected with shims or adjustment screws where applicable.
- Spark plug & ignition - Fit the correctspec plug, set the proper gap, and ensure the cap and lead are secure. If ignition timing appears off or inconsistent, have the ignition checked professionally.
- Address internal wear - If compression is low or oil burning is evident, a topend refresh (piston/rings, hone, valve work) will restore efficiency and reduce heat. This is not a quick trail fix but a reliable longterm solution.
- Riding technique adjustments - During technical sections, reduce prolonged idling and give occasional bursts of throttle to increase airflow. On hot days, take longer breaks and avoid overworking the engine in deep mud or sand.
Parts & replacements to prioritize
- Air filter element (foam) frequent, inexpensive maintenance item.
- Spark plug keep a fresh spare matched to CRF110F specs.
- Engine oil & filter use recommended weight; change more often under hard use.
- Gaskets & seals for intake or exhaust leak repair if suspected.
- Topend components piston, rings, and head gaskets if compression faults are diagnosed.
When to seek professional service
If you experience persistent power loss, white smoke, severe oil consumption, or repeated overheating after basic checks and fixes, have the CRF110F inspected by a qualified technician. Internal wear, head gasket failure, or complex ignition issues require diagnostic tools and shop-level repairs.
Maintaining cooling performance season to season
- Keep the shrouds and fins clean after every ride.
- Service the air filter and oil on a regular schedule based on riding conditions.
- Store the bike in a way that allows airflow around the engine avoid covering when hot.
- Periodically check valve clearances and ignition components as preventive maintenance.
Addressing dirt bike overheating on a 2018 Honda CRF110F is often straightforward with focused inspection and routine maintenance. Start with airflow, filter, and oil checks, then move to carburetion and valve adjustments if temperatures remain elevated. These practical steps keep a 110cc youth trail bike running cooler and more reliably on the trail or track.
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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.
