Fast Trails Performance- Overpowered Minibikes, Parts, Hop-ups, Service

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Ftp Big Bore kit Installation Tips:   BUY,BORROW, or STEAL a Honda or Cylmer Manual if you are unfamiliar with this engine rebuild. It is just like an OEM rebuild. There are many guidelines available online by searching with Google, but the best guide is the Cylmer manual.

Engine:

Make sure your engine and bike are spotless prior to beginning any work. When disassembling the engine you do not want ANY dirt falling into the internal areas. It is also much more enjoyable to work on a clean bike.

Cylinder:  

Wash your new cylinder in HOT SOAPY Water to remove any machining residue.   Dry completely and oil with fresh engine oil.

Clutch:

The four screws holding the clutch center cover on are sometimes VERY tight. Make sure you have the proper Phillips screw driver!! Or better yet use an impact gun. These screws often strip. Not to worry, Simply drill the heads off, remove the cover (remember the gasket may be a little ‘stuck’ so work the cover off gently). With the cover removed, the remaining screw threads are easily removed with vise-grips.   Now look inside your FTP gasket kit and thank yourself for buying from professionals!! We are the only supplier that sends new screws and a new gasket for this clutch center cover!!

   (this cover/ clutch is also the ‘oil sling’ you will see a black gummy almost rubber like substance behind the clutch center and in the clutch. This is engine debris/ dirt filtered out of the oil by centrifugal force as the oil is pumped through the clutch. CLEAN IT OUT!  This is basically the oil filtration on this engine.

Obtain the proper clutch nut socket to remove the clutch. You are about to double or triple the horsepower of your 50. You do not want to start out by hammering on the end of the crankshaft with a punch to loosen the Clutch nut. It works, but is this how you want to start your rebuild??    The crank will be under enough stress with the hop up parts, you don’t want to damage it before you even fire the motor!!!

Oil Pump:

Before Installing your Heavy Duty oil Pump you must drill out the oil passage to the top end of the engine.   

     Remove lower cylinder stud so you can get your drill in straight.

     Drill the oil passage out to 2 mm or 5/64.

     Carefully clean out any metal shavings.

Valves:   If installing our High lift cam, or installing our super head remember:

   Valve clearance should be: 0.03-0.07mm or 0.001-0.003 in

Piston Rings: To be thorough with your rebuild you should make sure that your Ring end gap is between 0.05-0.02mm or 0.002-0.008 in

Torque Specs:

Refer to an approved Honda manual for all the torque specs.   Carefully following torque specifications is important. Increase the Head stud Torque by 25% for factory specifications. After initial start up. Warm up engine for 4-5 minutes blipping the throttle to seat the rings. Allow engine to complete cool, then re-torque the head bolts.

Fast Trails Performance Big Bore Installation (Incomplete)

This instruction guide is written to help you with the basic installation of FTP’s Honda XR/CRF 50 Big bore kit.   This guide assumes that you have the necessary tools and the knowledge to use these tools.   It is not a substitute for mechanical ability.   If you do not have experience working with bikes, engines, or basic automotive repair, do not attempt to install this kit your self.

    We will try to outline the basic steps for you in a step by step guide. This guide applies to Stage 1, 2, and 3 kits.   Installing the stroker cranks should be done with a complete repair manual by experienced mechanics.

1)   The First step prior to even rolling the bike in the work shop is to WASH YOUR BIKE!! You are about to disassemble your engine and you do not want dirt falling into the inside of your new engine.   Use mild soap and hot water with a wash mitt or rag. A bio degradable de greaser such as Simple Green may help with some of the caked on grime.   Make sure you get under the gas tank and underside of the frame directly above the engine.

2) Drain the Oil. The oil drain bolt is a 17mm bolt under the front right side of the crank case. Start the engine and warm it briefly. Remove oil drain bolt let oil drain into a pan. 

Allow engine to cool prior to disassembly.

Pic.

3) After the bike is cleaned, dried and drained of oil, find a suitable sturdy Stand to put the bike on for its rebuild. Bike stands are great, but Milk Crates or sold block of wood work as well.

4)Now prior to putting the bike on the stand there are a few things to do before you put it on the stand as you need access to the underside of the bike.

 Spray WD-40 or other penetrating type lubricant on bolts such as: the Cylinder head stud bolts. Shifter bolt, Kick starter bolts, Exhaust nuts on cylinder head etc. to allow the penetrating fluid to work while we prepare the rest of the bike.

   A) Find Top Dead center on your engine. You will want to do this prior to your next step of removing the cam chain tensioner.

     To find top dead center. - With the bike in Neutral, completely remove the 10mm bolt on the shift lever, and then remove the lever.

     Remove the three 8mm bolts holding the left Crankcase cover mounting bolts.

Pic.

    B) Remove the camshaft cover (big round cover on left side of head) on the cylinder head by removing the 10mm bolt opposite (right side of head, in center of finned rocker arm covers) the Camshaft cover.

Pic Bolt,

Pic. Cover.

     Remove the spark plug cap from the spark plug to avoid any possibility of engine firing.

     Rotate the flywheel until the “T’ mark on the magneto/flywheel is aligned with the Small notch in the crankcase. (Basically pointing straight up).

Pic.

     Check that the camshaft sprocket mark is facing forward and aligned with the small notch in the cylinder head (basically pointing forward) If it is not, Rotate the Flywheel/ magneto one rotation until it is aligned with it index mark again and check camshaft sprocket index mark again. It should be aligned.

Pic.

5) You can now remove the cam chain tensioner from the underside of the crankcase. It is a 14mm bolt under the crankcase on the front left side of the engine. It is angled slightly toward the front of the bike.

    This bolt is spring loaded so be careful not to loose a) the 14mm bolt and sealing washer b) the spring above it and c) the camshaft chain tensioner push rod, which will slide out on it own or after you pull it out with the little finger.

6) Now on to the Clutch side. These steps are only necessary when installing a high volume oil pump with is highly recommended with any kit over 75cc’s.

     Remove the rear brake lever return spring. If you don’t have a spring tool, a shoe lace works great.    Remove the rear brake adjusting nut and spring from the rear wheel/drum assembly in order to lower the lever out of the way.

 7) Completely remove the Kick-start lever clamp bolt and remove the kick starter.

 8) Now support the bike by having a friend hold it upright.  Then remove the four 12mm Foot peg retaining bolts on the underside of the engine crank case, and then remove foot pegs and kickstand assembly.

9) You are now ready to place the bike on a stand.

10) You must remove the front wheel and fender in order to continue the disassembly. Remove the 14mm Front brake cable adjustment nut and spring.   Remove Cable from drum arm.

   Remove Allen bolts (2 per side) holding the Plastic fork guards in place.   Now using a 14mm and 17mm wrench remove the front axle bolt.   ** If you must tap the axle bolt in order to remove it. Put the Nut back loosely to protect the bolt threads prior to tapping the axle bolt out.  

   Remove front wheel and axle spacer.

Remove front fender by removing the three 10mm Bolts holding it to the bottom triple clamp.

10B) Remove the rear fenders. A)removing the two 8 mm bolts under the rear fender.B) Remove the two Phillips head screws holding the side shrouds into the gas tank. C) remove the two plastic pins holding the front of the Gas tank shrouds but prying the center of them up with a small flat screw driver. When the centers are raised, remove the Pins.

 The entire rear fender, seat and Front Shrouds can now be removed as a unit.

You must remove the exhaust assembly.   A) Remove the 10 mm bolt holding the muffler bracket to the rear sub frame. B) Remove the two 10mm nuts holding the exhaust flange into the cylinder head and remove the exhaust.

11) We are now ready to begin disassembly of the Top end of the engine.

Remove the 10mm bolt holding the Air filter to the frame.

Remove the two 8mm bolts holding the intake manifold to the cylinder head.

Now remove the Carb, Intake manifold and Air filter together. Once out, you will have to Screw the top of the carb off to remove the throttle cable, carb slide, etc.

REPLACE THE 10MM BOLT THAT HELD THE AIR FITLER TO THE FRAME ALONG WITH THE GROUND WIRE THAT GOES UNDER IT or you will be really scratching you head afterwards wondering why the bike won’t start.

Double check that the engine is at Top Dead Center.

    Remove the two 8mm bolts holding the camshaft sprocket in place. You may have to have a friend hold the Flywheel/ magneto to stop the engine from turning over. When the bolts are removed, remove the cam sprocket. Also remove the Cam Shaft dowel pin located in the center of the camshaft. You will need to re use this in the new cam.

12) Now with the cam sprocket removed, you can remove the four 10mm bolts and washes holding the top of the cylinder head on.  Not that the lower right side stud uses a copper washer rather than the regular steel washer.   This is important as this stud is an oil passage way and the copper washer is needed on this stud to seal the oil passage. Do not lose this washer.

13) Once the four head bolts and washers are removed you can remove the Cylinder head. If it is ‘stuck’ due to an older engine or dried up head gasket, lightly tap the cylinder head with a rubber mallet or piece of wood.

14) With the cylinder head removed note the position of the dowel pins that center the Cylinder head and remove them.   If they are difficult to remove, wait until you get the cylinder off in step *** to do so.

15)   Before sliding the cylinder off, remove the 10mm bolt and sealing washer from the left hand side of the cylinder. This bolt holds and positions the camshaft chain idler wheel.

16) Slide cylinder off of the cylinder studs.   A light tap with the rubber hammer may be required to free the cylinder from the base gasket on older engines.   The Cam chain idler wheel will fall out with it.

 As you are removing the cylinder be careful to support the connecting rod and piston as they come out the bottom of the cylinder.

   When the cylinder is removed, place clean rags into the crankcase around the connecting rod. This will keep any foreign debris or the piston c-clips from falling into the bottom end of the engine (requiring a complete tear down to retrieve.

    Remove the dowel pins from the cylinder for use with the 88cc cylinder. If they are difficult to remove, Place a long punch through the lower holes and tap them upwards and out.

 Pic.

17) Piston Removal. Wearing safety glasses to protect you from possible flying c-clips. Remove a c clip from one side of the piston.

    Push the Piston wrist pin toward the direction of the removed c clip to remove the piston.

   If this is difficult to do, locate a piston pin removal tool or use a small (i.e. 7mm 1/4drive deep socket) to help you push it out while supporting the connecting rod. However,

DO NOT USE EXCESSIVE FORCE AND RISK BENDING THE CONNECTING ROD WHILE DOING SO. If need be Make a connecting rod hold tool (see note) and locate a piston pin removal puller.

18) With the entire top end of the engine off, we can now begin installation of the High Volume oil pump.

     Remove the 8mm bolts holding the right side crankcase/ clutch cover on.   *there is no need to remove the14mm clutch adjustment nut in the center of the cover as this will require re adjusting the clutch.

    The cover may require a tap from a rubber hammer to break the gasket adhesion. Then wiggle the cover off evenly so it comes off the kick starter shaft evenly.  

   Remove the Ball retainer and spring from the center of the clutch if it has already fallen out. 

   Remove the Oil tube and spring from the center hole of the clutch.

   Remove the clutch release lever.

    Remove the Cam plate.

    Remove the four Phillips Screws holding the Clutch outer cover. ** These screws are Usually VERY TIGHT from the factory. Ensure you have the proper sized Screw driver when attempting to remove but we suggest you use an IMPACT DRIVER with the proper sized Phillips head bit.   The heads of these screws are easily stripped if you are not careful and will require you to carefully drill the heads off to remove the cover and then the threads. You will then have to get replacement screws from a local Honda Dealer (part# 93600-05010-0A) you want to avoid this hassle so use extreme care, patience and proper tools. 

   When removing this cover take care not to damage the gasket as you remove the cover. This gasket is not included in the kit and you do not want to damage it. If you do you must replace it. (Honda part # 22119-GW8-680 )

   When you have this cover off it is a good time to clean out the ‘gunk’ that has accumulated behind it. You may find a lot of dirt and clutch deposits behind this cover.

    With the Clutch outer cover removed, you can straighten the locking tabs on the center clutch nut. To remove the center clutch nut use the appropriate clutch nut removal socket and hold the Clutch housing using a strap wrench. An impact wrench with the proper four prong socket (Honda part# 07716-0020100).

    * We do not recommend tapping the clutch nut counter clockwise with a punch and hammer to loosen the clutch nut. It may work, but puts un necessary stress on a crankshaft that you are about to put twice the horsepower through.

You can now slide the main clutch assembly off the output shaft.

You now have proper access to the oil pump.

It is held on by three large Phillips screws. Once you remove these three large Phillips screws the oil pump comes right off.

   ** Before installing the High Volume Oil Pump, you must drill out the oil passage to the top end of the engine with a 2mm or 5/64 drill bit.

   To do this properly you will need to remove the lower right hand side cylinder stud. This will allow you to get your drill in straight.

   The easiest way to remove the stud is to use the ‘Jam nut’ method.   Take two 10mm nuts and thread them on the stud. Using two 10 mm wrenches, ‘jam’ them together by tightening them into each other.  

Now turn the nut on the bottom (closest to the crankcase) counter clockwise. Because it is ‘jammed’ against the top nut, it will turn the stud out of the crankcase.   When you are finished with the oil passage modification, you can tighten the stud down (does not need to be very tight (before taking your two 10mm wrenches and ‘unjamming’ the nuts but turning them apart.

With the stud removed take your 2mm or 5/64 drill bit and drill out the small oil passage to the top end. Make sure your drill straight and careful with a sharp bit.

   Pic.

   Pic.

Vacuum out all metal shavings or blow out the passage way with compressed air. As you have seen the oil passage hold is very small and will not take much to clog resulting in a blown engine.

   Install the new High Volume oil pump and new gasket.

*** Make sure that you align the drive shaft with the slot in the oil pump drive. You can feel them align if you twist the oil pump until there is not tension holding is away from the cases. If they are not aligned your pump will not want to sit flat against the case.

 Re Install the three large Phillips screws holding the oil pump in place alternating as you tighten down the screws.

If you are installing Heavy Duty clutch springs, Now is the time to do it prior to Re installing the clutch side of the engine.

   If not skip to “Reinstall the clutch assembly”

Reinstall the clutch assembly:

 1) Slide the Clutch assembly back on the main shaft ensuring that the drive gear meshes with the big primary drive gear and that it is inside the rear of the clutch ok.

2) Replace the Tabbed Lock washer on the crankshaft splines.

3) Replace the Cupped washer. Make sure the side of the washer marked ‘outside’ faces out.    

4) Replace the Center clutch nut with the Clutch nut socket. Tighten to 42N’M or 31 Ft Lbs. Make sure one of the tabs of the tabbed lock washer lines up with on of the indents on the Clutch retaining nut.  

5) Bend one or more of the tabs of the tabbed lock washer into the slots of the retaining nut.

 ** We do not recommend tightening the clutch retaining nut by hammering it with a punch and hammer in order to tighten it. We suggest you get the proper clutch nut socket. (Honda part number-07716-0020100)

6) Replace the Clutch outer cover, Bearing and Screws. Screws should be 5N’M or 44 In-Lbs.

7) Replace spring and oil tube into the cam plate.

8) Replace cam plate assembly

9) Install clutch Release lever ensuring it is placed on the spline so it aims toward the center of the clutch.

10) Install the ball retainer and spring.   To aid in holding these pieces in the right spot you can apply a dab of grease to the spring on the ball retainer prior to installing the right crankcase cover. If this becomes difficult, sometimes the best way for beginners is to lay the bike down on its left side so that gravity holds them together and centered.

11) Replace the right Crankcase cover ensuring that the dowel pins are still intact.   The cover gasket ‘should’ be replaced. If you have damaged it in any way, you will need to replace it.   Although we have heard reports that it can be reused over and over again if it was not damaged during disassembly ;-)

12) With your Oil passage drilled out, Heavy duty oil pump installed and Heavy Duty Clutch Springs (optional) installed, we can move onto the top end staring with Piston Assembly.

 Installing the Piston Rings.

 A) Gapping the rings.   All our kits come with precision machined Rings and cylinders. Very rarely will you have to adjust the ring end gap, but it is good to check prior to installing.

    With the new cylinder on the work bench, carefully install one of the two upper compression rings into the top of the cylinder. Use the piston to push it into the bore slightly to ‘square’ it up in the cylinder.

   Measure the end gap of the ring while it is in the cylinder.   A feeler gauge is needed and the end gap should be 0.05mm-0.02mm or 0.002-0.008 inches.  

   Do this with both the upper compression rings (the thicker rings).

The oil control set (two thin and 1 wavy ring do not need to be gapped)

   B) To install the rings on the piston. 

Start with the wavy ring which goes in the bottom groove. The ends of the ring should NOT overlap when installed.

   The thin rings get slip around this wavy ring. One below the wavy ring, and one above so that the wavy ring is ‘sandwiched’ in between.

     See pic for placement of the rings end gap. You do not want the ring gaps to all be in the same place.

     The solid black thick ring goes on next. Followed by the thick ring with the silver or greyish color ring going in the very top groove.

 Install the rings so that the miniature “N” or marking faces up.

    Place the ring gaps so that they are at “2 o’clock  and the other at “10 o’clock” (when the piston is facing you with the intake side up (as 12 o’clock).

C) With the rings installed you can install one of the c-clips.

Piston installation. Ensure that the rags you stuffed in the bottom end are still in place in case you accidentally drop a c clip in there.

   Position the piston over the connecting rod so that the “In” mark (or larger of the two valve cut outs) is facing UP. Slide the piston pin through the side of the piston that does not yet have a c clip installed (coat it in fresh engine oil first).   When the piston pin is installed completely, you can install the second c clip.

   ***Make sure the c clips are firmly positioned in their grooves. An in properly installed c clip will destroy the engine.

With the piston installed, you can Slide the cylinder over it for installation.   This procedure takes experience and patience.

   First Ensure you have prepare the cylinder for installation.   The cylinder is pre honed and ready for install after you wash out any machining residue.

    With HOT soapy water (dish soap works great) clean the inside bore of the cylinder to remove any machining residue.   When you are finished drying it, you should be able to pull a clean rag or paper towel through the bore with No dirt visible on the rag.

   Oil the dry cylinder bore with fresh engine oil prior to installing.

   Ensure that the cylinder dowel pins are in place.

    Install the cylinder base gasket.

    Install a large rubber o ring in the lower oil return passage. You may want to put a dab of grease on the o ring to help hold it in place while the cylinder gets installed.

   If you do not have a ring compressor you will have to carefully slide the cylinder over the piston while squeezing the rings together with your fingers or a hose clamp. TAKE YOUR TIME and stop and try again if it isn’t going well.  

   You will have to ‘fish’ the timing chain through the side of the cylinder as you lower it down

   When installed you should be able to hold the cylinder down with one hand and rotate the engine (by turning the flywheel) with the other. The piston should move smoothly and easily.   (When finished this test, return the flywheel to the Top dead center mark)

   Install the timing chain idler sprocket in the cylinder by holding it with long nose pliers so you can position behind the bolt hole.   Install the bolt ensuring that the oil sealing washer is in place. Tighten the bolt to