Yamaha F255 Outboard Rebuild Part 5: Top End
After rebuilding the bottom end of our Yamaha F225 outboard, it’s time to rebuild the top end.
Watch the video above and follow the steps below to rebuild the top end of a Yamaha F225TXRC outboard. Use our Yamaha F225TXRC outboard parts diagrams for additional reference.
Tools and Parts – Yamaha F225 Top End Rebuild
- Torque wrench capable of measuring angles
- Cylinder head assembly (port)
- Cylinder head assembly (starboard)
NOTE: Aside from the tools and parts listed above, you’ll need a well-stocked toolbox that includes a ratchet and socket set, Allen set, wrenches, screwdrivers, pliers, etc. If your F225 is in relatively good condition, you may be able to get the cylinder heads resurfaced at a machine shop. However, we’re completely replacing the top end with brand new Yamaha F225TXRC cylinder head assemblies.
NOTE: If you’re installing new Yamaha F225 cylinder head assemblies, you must first remove the cam tensioners and the camshafts.
Disassembling Yamaha F225TXRC Cylinder Head
Step 1. Remove the cam chain tensioner assembly, followed by the four cam caps on each camshaft from the port cylinder head in the sequence shown in the image below, before removing the camshaft.
Step 2. Remove the cam chain tensioner assembly, followed by the five cam caps on each camshaft from the starboard cylinder head in the sequence shown in the image below, before removing the camshaft.
Watch the clip below to see the cylinder head disassembly segment of our Yamaha F225TXRC bottom end rebuild video.
Installing Yamaha F225TXRC Cylinder Head (Port Side)
Step 1. Install the water shut grommet and dowel pins into the crankcase, and make sure the crankshaft is in the correct position by aligning the timing belt drive gear with the mark on the crankcase.
Step 2. Clean the crankcase mounting surface with contact/brake cleaner, then install a new cylinder head gasket and the cylinder head onto the crankcase.
Step 3. Oil the cylinder head bolts, then tighten and torque them in the sequence shown in the image below.
1. Torque bolts 1-8 to 14 foot-pounds
2. Torque bolts 1-8 to 27 foot-pounds
3. Torque bolts 1-8 an additional 90-degrees
4. Torque bolts 9-11 to 10 foot-pounds
5. Torque bolts 9-11 to 20 foot-pounds
Watch the clip below to see the port cylinder head segment of our Yamaha F225TXRC bottom end rebuild video.
Installing Yamaha F225TXRC Camshafts (Port Side)
Step 1. Apply assembly lube to the valve lifters and surfaces the camshafts will rest on, then install the port camshafts into the cylinder head, and lightly oil and install the camshaft oil seal.
Step 2. Install the camshaft caps, and tighten and torque them in the sequence shown in the image below.
1. Torque the bolts to 5.8 foot-pounds
2. Torque the bolts 12 foot-pounds
Step 3. Install the cam chain tensioner assembly, and torque its mounting bolts to 8.7 foot-pounds. Remove the retaining pin if it’s still in the tensioner.
Watch the clip below to see the port camshafts segment of our Yamaha F225TXRC bottom end rebuild video.
Installing Yamaha F225TXRC Cylinder Head (Starboard Side)
Step 1. Install the water shut grommet and dowel pins into the crankcase, and make sure the crankshaft is in the correct position by aligning the timing belt drive gear with the mark on the crankcase.
Step 2. Clean the crankcase mounting surface with contact/brake cleaner, then install a new cylinder head gasket and cylinder head onto the crankcase.
Step 3. Oil the cylinder head bolts, then tighten and torque them in the sequence shown in the image below.
1. Torque bolts 1-8 to 14 foot-pounds
2. Torque bolts 1-8 to 27 foot-pounds
3. Torque bolts 1-8 an additional 90-degrees
4. Torque bolts 9-11 to 10 foot-pounds
5. Torque bolts 9-11 to 20 foot-pounds
Watch the clip below to see the starboard cylinder head segment of our Yamaha F225TXRC bottom end rebuild video.
Installing Yamaha F225TXRC Camshafts (Starboard Side)
Step 1. Apply assembly lube to the valve lifters and the surfaces the camshafts will rest on, then install the starboard camshafts into the cylinder head, and lightly oil and install the camshaft oil seal.
Step 2. Install the camshaft caps, and tighten and torque them in the sequence shown in the image below.
1. Torque the bolts to 5.8 foot-pounds
2. Torque the bolts 12 foot-pounds
Step 3. Install the cam chain tensioner assembly, and torque its mounting bolts to 8.7 foot-pounds. Remove the retaining pin if it’s still in the tensioner.
Watch the clip below to see the starboard camshafts segment of our Yamaha F225TXRC bottom end rebuild video.
Installing Yamaha F225TXRC Cylinder Head Covers
Step 1. Install new cylinder head cover gaskets into the cylinder head covers, and apply Yamabond to the areas shown in the image below.
Step 2. Install the cylinder head covers onto the motor, then use blue threadlocker on the cover bolts and tighten them down.
Watch the clip below to see the cylinder head covers segment of our Yamaha F225TXRC bottom end rebuild video.
With the top end of our Yamaha F225 rebuilt, the next process is working on rebuilding the timing and electrical systems. Watch our Yamaha F225TXRC Outboard Part 6 video below to see how to get that done.
