The Stomp Z3-140 Dirt Bike, stomp 140cc dirt bike z3-140 still boasts the ‘exclusive to Stomp’ SR140C Z40 cam engine. Stomp buy in the YX140 and then fettle the engine with stiffened valve springs & a high lift race cam (known as the Z40 cam). The result is 2hp more than any other YX140 engine on the market. It might not be quite Zhongshen 155 territory but its most of the way there and significantly cheaper to install than the ZS155. If you look after the SR140C, it will prove a very reliable and cheap engine to run. The new look stomp 140cc dirt bike z3-140 also comes with updated pro foot pegs and polished hubs to complete the new look.
Stomp Racing SR140C Z40 race cam
Start-in-gear, all-up 4 speed gearbox
14hp at rear wheel
26mm race carb with double foam filter
Aluminium shot blast finished cases with Stomp logo
CNC oil cooler with braided steel hoses
SDG2 heavy duty cradle frame for ultimate stiffness and control
Removable rear subframe & bolt on engine hangers
Revised light-weight tig welded 430mm swing arm
Extended 735mm cnc machined usd oil filled forks
Drop forged black anodised triple clamps (yokes)
Nitrogen filled 290mm piggy back shock with steel bushes
14/12 sdg wheels with steel rims for strength
Superb durable and tough innova pattern mx tyres
Improved and revised light-weight brake master cylinders and callipers
Vented light-weight rotors
Alloy oval exhaust muffler
Mandrill bent big bore 32mm OD race pipe
Features full length alloy heat shield for style and protection
Pro-taper style minibike bars
Renthal style soft rubber grips
Forged alloy clutch & brake levers
420 KMC chain with engraved alloy/nylon chain guide
420 41t lightweight durable rear sprocket
420 16t front sprocket
Fold back gear selector
NEW upgraded PRO foot pegs
NEW reinforced poly resin 5.5 ltr fuel tank with alloy cnc filler cap
NEW revised firmer seat with Stomp logo
NEW Detroit hi impact polypropylene plastics
Wrap around crf number board with front brake pipe tidy
New Stomp race graphics kit with Stomp race sponsor’s logos
You have chosen wisely, the Pit Bike / Kayo Quad Bike you have bought in order that you will enjoy your machine to the full.
Your bike has been supplied in a crate. This is NOT the same as buying a bike fully PDI’d (Pre Delivery Inspection) bike from a dealer. It is entirely your responsibility to ensure a qualified motorcycle mechanic puts your bike together correctly. Failure to do so will invalidate the warranty supplied with your bike.
In order to qualify for this warranty you must fill in the supplied Proof Of Purchase, PDI & Warranty & post it to the supplied address. in your user manual
GUIDE FOR STOMP BIKE ASSEMBLY
This document is supplied only as a guide to a professional and may not be exhaustive. Each machine may require individual attention & therefore ONLY qualified persons should only carry out the following:
Remove Bike & all accessories from crate & inspect to ensure all necessary parts have been supplied correctly
Mount shock (where applicable)
Tighten lower fork bolt, reached from underside of forks.
Mount front wheel & ensure free rotation – check for potential bearing &/or brake drag Ensure all frame bolts are tight (use thread lock compound where necessary) – use locking wheel nut (supplied)
Check spokes and tighten if necessary
Loosen triple clamps around fork legs & set desired fork height. Use copper grease on triple clamp bolts to prevent damage to the alloy threads & then firmly tighten
Fit handlebars and clutch cable to clutch lever
Pump front brake lever until firm (bleed if necessary). Check front braking system for potential leaks or damage by pulling brake lever very hard several times. Visually inspect all joints for leaks & remedy where necessary. Spin wheel to ensure calliper is releasing from disk
Fit rear brake pedal where necessary & repeat procedure described for front brake
Check fluid levels, top up with DOT4 where necessary
Fit front mudguard using thread locking compound where required
Fit foot pegs
Loosen rear wheel & adjust chain tension. Find tightest point in chain by spinning rear wheel, there should 15mm up & 15mm down at the longest section of chain with rider sat on bike. Ensure chain runs true & is on top of chain roller. Ensure chain does not foul on rear chain guide (use shims/washer to space if necessary)
Working from front to rear, ensure all nuts & bolts are tight. Where no nyloc nuts or spring washers are present, ensure thread-locking compound has been used. If none has been used during factory assembly, remove nut or bolt, apply locking compound & re-tighten. Pay particular attention to the following critical safety areas: Wheel nuts, brake calliper bolts (thread lock), Top & rear engine bolts (frame must be hard tight against the engine, use thread lock), chain tensioners, rear shock bolts, triple clamp bolts (yokes), Handlebars, brake/ clutch/throttle, swing-arm, front & rear sprocket
Check all engine hardware is tight, (including but not exclusive): flywheel, inlet manifold, exhaust bolts,
Remove Transit Oil and Replace with a quality Motorcycle 10w40 such as Putoline DX4 semi synthetic 10w 40 4-stroke engine oil
Adjust tappets. Set engine to TDC (ONLY rotate engine anticlockwise) & check cam timing alignment (cam sprocket/cylinder head – adjust is necessary), remove tappet covers & adjust tappet clearances : inlet ~0.15mm - exhaust ~0.20mm
Fully ensure nothing is touching the exhaust system. On oil cooled models, ensure the oil cooler pipes do not touch the exhaust manifold
that the heat protection springs are located on the correct part of the pipe in order that should they touch the exhaust the heat will not damage them.
Ensure all cables pipes & wiring are away from moving components such as the wheels, use cable ties where necessary Carb –SS140 – set needle height on second notch from bottom for UK conditions. 110/125/150 engines normally do not need adjustment
Fuel bike & check for fuel leaks
Check oil level with bike in upright position using dipstick. Top up with 10W 40 semi synthetic oil, if necessary
Adjust tension for both clutch & throttle cables
Ensure wheel spokes are tight & wheels run true
Start engine & warm up (using choke if necessary). Set idle speed so engine ticks over comfortably without stalling or racing
(bearing in mind that the pads will need to bed in prior to optimum performance)
Re-Adjust throttle cable & clutch cable if required
Check wheel bearings for any sign of wear of free-play
Check brake calliper operation & brake pad wear
Check spark plug gap ~0.6mm-0.7mm
Check tyre pressures
RIDING TIPS FOR LONG ENGINE LIFE - IMPORTANT
Do not over rev your engine as you may cause damage to valves. This is particularly applicable where an inner rotor kit is used. Under load the engine is capable of revving into major valve bounce that can cause permanent damage to your engine. If you feel the power dropping every 10 hours use.
Do not stamp through the gears – always use the clutch.
If you miss a gear do NOT stamp into gear from high engine revs.
Do not drop your clutch heavily, or slip it unnecessarily.
Do not allow your air filter to fill with fuel – this can occur by incorrect float height setting – see above, or the bike falling onto its side.
If the engine back-fires while the air filter is filled with fuel, it may ignite – check air filter regularly while riding.
STOMP PROBLEM SOLVING
Exhaust Glows Red (fast tick over) – Carburetion too lean, richen mixture via raising needle
Engine misfires at mid to high engine speed, open throttle – Mixture too rich, drop needle
Engine Pops & bangs on over-run – mixture too rich, drop needle
Engine kicks back hard whilst starting – Ignition too advanced, or mixture too lean
Weak Spark – Pick-up coils too far from rotor (where inner rotor kit fitted) or bad earth
No spark – Either poor earth or faulty Rotor Coils/CDI/Coil/Lead/Cap/Plug – use moving coil multimeter to diagnose
Fuel leaks from overflow – Floats set incorrectly or blocked by debris or sticking
Engine runs fine, but then starts to misfire – faulty rotor coils/CDI/Coil/Plug
Rattles from engine – Tappets set incorrectly
Engine will not tick over when warm – tappets set incorrectly
Engine will not return to idle & races – sticking throttle cable
STOMP CORRECT JETTING
Take out the spark plug and check the electrode; the colour should be golden brown. If it is white, the engine is running too lean (not enough fuel). If it is black (sooty colour) it is too rich (too much fuel). If it is white & black, the engine is VERY lean & causing misfire, which you should be able to detect whilst riding. As your jets are close to what they should be for the UK, minor alterations can be made by
To add more fuel, raise the needle one notch. This is achieved by removing the carb from the engine, removing the throttle slide, removing the needle & adjusting the position of the circlip. Conversely, if you need to reduce the amount of fuel, drop the needle one notch. Re-assemble the carb & continue testing, remembering to check the colour of your spark plug.
Once you have achieved the correct full load fuelling, you can set the idle mixture screw. The 140 & 150 engines like to run very rich at idle, this way you get a clean progression from idle jet to main jet. To achieve a richer mixture, turn the air screw (next to filter) clockwise. Idle speed may need to be adjusted at same time to keep engine running.
It is advisable to fully service and lubricate the bike prior to leaving the bike unused/unattended for any length of time.
It is advisable to fully drain the tank and carb of fuel prior to leaving the bike unused/unattended for any length of time.