This article will introduce the process of installing Kitako's "145cc LIGHT Bore Up KIT" into the popular moped model JC92 Grom (FNO, JC92-1000001-1099999). In this 4th installment, we will be installing the camshafts and cam sprockets, adjusting the valve clearances, and installing the covers. In the previous installment, the basic engine parts (piston, cylinder, and cylinder head) were already installed. This time, camshafts and cam sprockets were installed and valve clearances were adjusted. Then, the oil gallery, cam sprocket cover, and crankcase cover will be assembled to complete the engine body.
The145cc LIGHT Bore Up KITfrom Kitako, which allows the stock cylinder head to be used as-is, is based on ø54mm gravity cast pistons and cylinders, and is also available as a set with high camshafts. The price is 28,600 yen without high camshafts and 38,500 yen with high camshafts.
The high camshafts for the bore up kit will be installed in this case. Once the camshafts are installed, make sure the pistons are at the upper dead center of compression and install the cam sprockets. In addition, put oil in the push rod part of the cam chain tensioner and move the tensioner to turn the oil.
(1) Prepare a Kitako high cam for the JC92 series that is compatible with the stock cylinder head.
(2) Before installing in the cylinder head, lubricate the camshafts with oil. Start with the bearing part.
(3) Next, apply engine oil to the cam mount area.
(4) After applying the oil to the cam mount area, spread the oil over the entire cam mount using your fingers to spread the oil.
(5) Apply oil thoroughly to the bearing on the other side, and rotate the bearing to allow the oil to blend in.
(6) The keyway for securing the cam sprocket is turned down 45° when viewed from the side
.
(7) The keyway is aligned so that the cam mounts align with the depressed area in the cylinder head.
(8) When installing the camshaft, check the location of the depression in the cylinder head.
(9) Align the cam mounts with the grooves in the cylinder head and set the camshafts into the cylinder head while slightly angling the camshafts.
(10) Once the camshaft is in as far as it will go, turn the camshaft to adjust the keyway position.
(11) Turn the camshaft to the right so that the keyway is at 45° to the inside.
(12) Now the camshaft can be set all the way to the back, with the front side cam mounts matching the groove position.
(13) The camshaft is set by moving the rocker arms and fine-tuning the camshaft orientation
(14) Make sure to insert the camshaft straight in and push the bearing part deep into the cylinder head.
(15) Once the camshaft is set all the way back, secure it using bolts + washers.
(16) After setting the bolt + washer by turning it by hand, tighten it using a T-wrench or other tool with a long tip.
(17) After tightening the bolt to a certain extent, tighten the bolt with a torque wrench to 10 N-m at the end.
(18) Once tightened, try turning the camshaft. If it seems reluctant to turn around, use the adjustable shim washers that are placed under the washers to make adjustments.
(19) Once the camshafts are secured, the cam sprockets are installed. The cam sprocket is easier to install if the cam chain is larger asso...
(20) Loosen the tensioner bolt at the bottom of the crankcase for a larger cam chain assoby.
(21) With the tensioner body in this position, loosen the tensioner bolt until it moves easily when the tensioner is pushed.
(22) Rotate the flywheel to align the mating mark with the case and align the piston to the upper dead center of compression.
(23) Install the cam sprocket. Check the protruding part pointed with pliers.
(24) Align this protruding part with the keyway on the camshaft and set the cam sprocket in place.
(25) Put the cam chain on the cam sprocket and set it on the camshaft, aligning the keyway and the projection.
(26) If it's too tight to align, loosen the cam chain tensioner further to make it easier to work with.
(27) Once set, check that the circled mark on the cam sprocket is aligned with the protrusion on the cylinder head side.
(28) After installing the sprockets, check again that the flywheel and case are aligned with the matching marks.
(29) After confirming that the seals are aligned, secure the cam sprocket to the camshaft with the cam sprocket bolts.
(30) Turn the cam sprocket bolt by hand and tighten it as far as it can go.
(31) While securing the cam sprocket with the universal holder, tighten it with a 12 mm socket wrench, and finally tighten it with 27 Nm.
(32) This completes the installation of the camshafts and cam sprockets.
(33) Once the cam sprocket is installed, remove the cam chain tensioner bolt.
(34) A 5 mm Allen wrench should be used here, with a slightly longer length because the bolt is located in a secluded area.
(35) When the cam chain tensioner bolt is removed, oil will flow out, so be sure to have an oil receptacle underneath.
(36) Loosen the cam tensioner bolt with a ratchet wrench fitted with a 5 mm hex wrench socket.
(37) Once the bolts are loosened a little, use a T-wrench for more efficient work.
(38) The cam chain tensioner bolt that came off. It is a flange type bolt and does not contain a washer.
(39) When the cam chain tensioner bolt is removed, a pushrod can be seen inside.
(40) Fill this pushrod with at least 4 cc of engine oil using the oil filler.
(41) Quickly install the cam chain tensioner bolt as the oil you put in flows out.
(42) After tightening the bolt with a T-wrench until it reaches the point where it stops, use a torque wrench to tighten the bolt to 10 N-m at the end.
(43) After tightening the cam chain tensioner bolt, check the operation of the tensioner arm.
(44) Press the tensioner arm and check that it moves smoothly.
(45) At first, if the oil is not turned, noise will be heard, so pour oil from the top to prevent noise.
(46) After pouring oil, move the tensioner arm again to turn the oil. When the oil is properly turned, the one-way valve works and the movement becomes heavier.
(47) Apply a little engine oil around the cam sprocket and cam chain.
Adjusting Valve Clearance
Since the valve clearance has been increased by loosening the adjusting bolt for the camshaft removal and installation, use the adjusting bolt to adjust the valve clearance to the proper value. The valve clearance is 0.08mm ±0.02mm on the in side and 0.20m ±0.02mm on the exhaust side.
(1) Valve clearance is adjusted with an adjuster at the end of the rocker arm.
(2) The tools used to adjust the valve clearance are a tappet adjusting wrench and a sixness gauge.
(3) The first step is to adjust the in-side valve clearance. Since it was loosened significantly during camshaft removal and installation, it should be tightened a little fi
(4) Clearance is 0.08 mm ± 0.02 mm; set a 0.08-mm siknes gauge on the contact surface of the adjuster and arm.
(5) With the sickness gauge inserted, set the adjusting wrench and tighten it.
(6) Turn the adjusting nut and adjust it so that there is a little resistance when pulling on the sixness gauge.
(7) Once adjusted, turn the handle with the adjusting screw in place and tighten the lock nut securely.
(8) After tightening the lock nut, pull out and insert a feeler gauge to make sure there is adequate resistance.
(9) After checking the clearance, use a torque wrench to tighten the bolts with a torque of 9 N-m. Tool size is 9 mm.
(10) タペットホールカバーを取り付ける。突起のある方が正面から見て左側になるようにセットする。
(11) Set the two bolts on either side that secure the tappet hole cover.
(12) Use the socket coma to turn the bolts and tighten them as far as they can go.
(13) Finally, use a torque wrench to tighten the bolt with a torque of 10 N-m.
(14) Then adjust the valve clearance on the exhaust side.
(15) The exhaust side is also loosened significantly, so tighten it a bit.
(16) The valve clearance on the exhaust side is 0.20 m ± 0.02 mm, so set a 0.2 mm siknes gauge on the contact surface.
(17) Set the tappet adjusting wrench, and adjust the tappet so that there is a slight resistance when the sixness gauge is pulled in and out as on the in side.
(18) It is just right that there is a little resistance at 0.2 mm on the Siknes gauge and not enough at 0.02 mm to get in.
(19) As with the in side, use a torque wrench to tighten the bolts to 9 Nm. Be careful not to change the clearance.
(20) After tightening with a torque wrench, check the clearance again with a sixness gauge.
(21) Set the tappet hole caps and tighten the two fixing bolts. Be careful not to drop the cap.
(22) Finally, use a torque wrench to tighten the cap with a torque of 10 Nm.
Incorporating the oil gallery and O2 sensor guard
The Kitako cylinder has an oil line fitting port for installing an oil cooler. Since an oil cooler will not be installed this time, an oil gallery will be installed. The O2 sensor guard will also be installed at the same time.
(1) Install the oil gallery on the cylinder.
(2) Set aluminum sealing washers on the banjo bolts.
(3) After setting the sealing washers, thread the bolts into the oil gallery.
(4) Set another sealing washer over the oil gallery.
(5) On the right side of the Kitako cylinder, a threaded hole (oil line) is drilled for installation.
(6) Align the mounting position and temporarily fasten the banjo bolt by turning it by hand.
(7) Tighten the two banjo bolts as far as they can be tightened by hand
(8) Tighten the bolt using a torque wrench. The tool size is 14 mm and the tightening torque is 15 N-m.
(9) This completes the installation of the oil gallery. The silver color was used in the photo shoot, but the original kit comes in black.
(10) Next, the O2 sensor guard is installed.
(11) Screw holes are provided in the front right side of the cylinder for mounting the guard.
(12) The guard will be installed in this manner.
(13) The mounting holes of the guard are aligned with the threaded holes of the cylinder, and the bolts are set in place using a T-wrench.
(14) Once the bolts are tightened to the point where they stop, use the torque wrench to tighten the bolts to 10 Nm.
(15) 02 sensor guard installed.
(16) Once the guard is installed, the 02 sensor wires are set into the clamps on the case.
(17) There are two clamps, so the wires are passed through them like this.
(18) Once the wires are set into the case, the coupler at the end should be out to the left side of the car body.
Incorporating the cam sprocket cover and crankcase cover
Install the cam sprocket cover and crankcase cover. The crankcase cover on the left side has a built-in stator, which is attracted by strong magnetic force. Therefore, when installing the left side crankcase cover, care must be taken not to get your fingertips pinched.
(1) Installing the cam sprocket cover.
(2) Prepare the cam sprocket cover.
(3) The cam sprocket cover contains O-rings, so make sure they are not damaged.
(4) Set the cam sprocket cover on the cylinder head and align the holes.
(5) Set the two upper and lower fixing bolts and tighten them by hand to a certain degree.
(6) Tighten the bolts with an 8mm T-wrench.
(7) Finally, use a torque wrench to tighten the bolts with 10 N-m.
(8) The left crankcase cover is installed.
(9) A gasket goes between the crankcase and the cover.
(10) Apply a thin layer of liquid gasket to the convex part of the crankcase cover gasket.
(11) There are two knock pins in the crankcase, the first is on the lower front side.
(12) The other location for the knock pin is on the upper rear side.
(13) Attach the gasket. Be careful not to break or bend it.
(14) After setting the gasket, check that the holes are properly aligned.
(15) Install the crankcase cover. The strong magnetic force will attract it, so be careful not to get your fingertips or other parts caught in it.
(16) Attach the crankcase cover to the crankcase while checking the position of the knock pin, etc.
(17) Eight bolts hold the crankcase cover in place, and only two of them are co-tightened with hose guides.
(18) The hose guides will be installed in two locations at the front (left side of the photo).
(19) Temporarily tighten the eight bolts. Do not tighten the bolts fully yet.
(20) Some bolts are set in a deep position, so a T-wrench is easy to work with.
(21) The harness clamps are co-tightened at two locations in the back (right side of the photo).
(22) The bolts are temporarily fastened, taking care not to stress the harness.
(23) Support the hose guide with one hand to prevent it from turning and tighten until the guide is secured.
(24) Using a torque wrench, tighten the guide at 10 Nm. Tightening is done by dividing the tightening into several diagonals.
(25) Once the crankcase cover is secured, the engine body assembly is complete.
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(3) After setting the sealing washers, thread the bolts into the oil gallery.
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