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About PRO50 2 Stroke Gas Backpack Concrete Vibrator Parts by Northrock
Genuine OEM PRO50 2-Stroke
Gas Backpack Vibrator Parts
The PRO50 2 Style Gas Backpack is one of the go-to gas concrete vibrator backpacks in the industry. The quality workmanship, lightweight, and efficient design for the PRO50 2 make it an obvious choice for any of your concrete jobs. The backpack gives you great maneuverability which gives ease to the handler. It is recommended to use only genuine Northrock parts for maximum efficiency and longer life of your equipment. Order genuine Northrock concrete vibrator parts from a trusted source at the best prices.
Find every replacement part for the Northrock PRO50 2-Stroke gas backpack concrete vibrator. OEM components for the motor, carburetor, starter, frame, and quick-disconnect drive system, shipped from an authorized Northrock supply channel.
The Northrock PRO50 2-Stroke is the workhorse gas backpack vibrator that has consolidated concrete on commercial pours for decades. Powered by a compact 2-cycle gasoline engine and a universal quick-disconnect drive, it pairs with any standard flexible shaft and head for walls, columns, footings, and bridge decks. DanseUSA is an authorized Northrock dealer stocking genuine OEM components, from complete pistons and carburetors down to individual gaskets, bearings, and shoulder strap hardware.
Use the shop-by-diagram pages below to identify the exact part you need by sub-assembly. Every part number on this page matches the official Northrock PRO50 2-Stroke parts list. If your unit is the newer 4-cycle model, see Northrock PRO50 4-Stroke Backpack Vibrator Parts instead.
For the full Northrock equipment catalog, visit our Northrock Parts hub.
| Specification | Detail |
|---|---|
| Engine Type | 2-Cycle gasoline, air-cooled, single cylinder |
| Fuel Requirement | Pre-mixed unleaded gasoline plus 2-cycle engine oil |
| Vibration Frequency | 10,000 VPM |
| Carburetor (Early Units) | Walbro WYK-104 (P/N 4175124, 2318890 complete) |
| Carburetor (Later Units) | Walbro WYK-144 (P/N 2318630 complete) |
| Starter | Recoil rope pull-start (Complete: 61042001B) |
| Quick Disconnect | Universal square-drive with spring-pin lock (Complete: 25AN1) |
| Compatible Shaft Lengths | 7 ft, 10 ft, 14 ft standard. Up to 21 ft available. |
| Compatible Head Sizes | 3/4", 1", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/2" |
| Frame | Tubular steel with shoulder harness, vibration-isolating engine mounts |
| Cross-Brand Compatibility | Drives flexible shafts from Wyco, Oztec, Wacker, Stow, Stone, and Mikasa |
The PRO50 2-Stroke is organized into 7 sub-assemblies. Select any assembly to view the exploded parts diagram, identify components by reference number, and order the exact OEM part.
Frame Assembly
Frame (62020031), complete harness (62020039), shoulder pad (4100333), buckle set (62022030), engine isolator shock absorbers (3058011, 3058012)
Motor Assembly
Complete piston (61122015), complete cylinder (61122014B), piston ring (94000015), flywheel (4191021A), spark plug (3055035), crankshaft bearings (3037014, 3035019, 3034012)
Starter and Clutch Assembly
Complete starter (61042001B), starter rope (4098073), pawl (4191016), pawl spring (4191017A), pulley (4191018), clutch drum (405C1), clutch spring (4000132)
Carburetor WYK-104 Assembly
For early-production PRO50 units. Complete carb (4175124, 2318890), repair kit (2318591), gasket and diaphragm kit (2318590), primer body (2318570). For carburetor-specific service parts, confirm fitment against your carburetor stamping before ordering.
Carburetor WYK-144 Assembly
For later-production PRO50 units. Complete carb (2318630), complete valve (2318843), primer (2318572), jet (2318891), flange (2318813), o-ring (2318701)
Handle Assembly 1
Complete handle (165G1), handle (165F1), complete throttle control (605A1), throttle lever (605B1), throttle body (605C1), wiring harness (610A1)
Handle Assembly 2
Complete handle (61042021A), throttle cable long (62010010), throttle cable (615A1), switch guard (270D1), switch (61040051), throttle (61040049)
Based on typical contractor use, these are the components that wear first on the PRO50 2-Stroke:
- Carburetor repair kit (2318591) and gasket and diaphragm kit (2318590). Service the carburetor annually, or sooner if you experience hard starts, fuel leaks at the primer, flooding, or fuel pulled through the air filter. The diaphragm hardens with age and ethanol exposure.
- Spark plug (3055035). Inspect at every 25 hours of operation, replace at 100 hours or sooner if fouled, oil-bridged, or eroded. A weak spark is the most common cause of a no-start condition on a 2-stroke.
- Complete starter (61042001B). Replace as a unit when the recoil fails to retract, the rope (4098073) shreds at the pulley, or the pawl (4191016) fails to engage the flywheel cup.
- Air filter (61110010A sponge / 61120018 paper). Clean the sponge filter every 10 hours with soap and water, oil lightly with 2-cycle oil, and wring dry. Replace when torn or permanently saturated. Concrete dust kills 2-stroke top ends faster than anything else.
- Quick disconnect release complete (25AN1). Replace when the spring pin no longer locks positively into the shaft adapter, or when the square drive shows visible rounding. A worn QD will eject under load and is a safety issue.
- Engine isolation shock absorbers (3058011, 3058012). Replace when cracked, compressed, or when operator-felt vibration noticeably increases. Worn isolators transmit damaging vibration to the frame welds and the operator's back.
- Piston ring (94000015) and complete piston (61122015). Replace when compression drops, the engine smokes excessively, or you notice loss of power under load. Always inspect the cylinder (61122014B) for scoring before reusing.
The 2-Stroke and 4-Stroke share the universal quick-disconnect drive, flexible shafts, and vibrator heads. The engine, fuel system, and most frame hardware are not interchangeable. Confirm your model before ordering.
| PRO50 2-Stroke | PRO50 4-Stroke (Pro 50-4S) | |
|---|---|---|
| Engine | 2-Cycle gasoline, requires fuel mixing | Honda GXH50 4-Stroke, no mixing |
| Fuel | Pre-mixed gasoline plus 2-cycle oil | Straight unleaded gasoline |
| Carburetor | Walbro WYK-104 or WYK-144 | Honda factory carburetor |
| Starter | Recoil pull-start (61042001B) | Honda recoil starter |
| Quick Disconnect | Yes (P/N 25AN1) | Yes (factory installed) |
| Flexible Shafts and Heads | Universal inventory. Likely reusable across both models (confirm fitment before ordering). | |
| Best For | Operators with existing 2-stroke fleets and parts inventories | New units, lower emissions, no fuel mixing |
Engine and Fuel
Always run pre-mixed fuel at the ratio specified on your 2-cycle oil bottle (typically 50:1 with modern synthetic oils). Mix only what you will use within 30 days. Drain the tank and run the carburetor dry before long-term storage. Stale or unmixed fuel is the leading cause of seized 2-stroke top ends.
Carburetor Identification
The PRO50 2-Stroke shipped with two Walbro carburetor variants. The WYK-104 fits earlier units; the WYK-144 fits later units. The model code is stamped on the carburetor body. Order the rebuild kit, gaskets, and primer assembly that match your specific carb. The two are not cross-compatible at the component level.
Flexible Shaft
Re-lubricate the inner core every 50 hours of operation. Remove the core on a clean surface, wipe it down, and apply a 1/16" coating of high-quality lithium grease. Do not over-grease, as excess lubricant creates drag and overheating. Replace the core if you see kinking, dry spots, or loss of flexibility.
General and Safety
Check all frame bolts and engine mount hardware before each shift. Inspect the harness pad (4100333) and buckle set (62022030) for wear. Always start the unit with the head clear of the form. Wear hearing and eye protection. Follow OSHA silica dust guidelines when consolidating dry mixes.
Need Help Finding Your PRO50 2-Stroke Part?
Share your model, carburetor stamping (WYK-104 or WYK-144), and the part number you are replacing. Our parts team confirms exact fitment before every order.
Frequently Asked Questions
Match the Ref. # on the diagram to the row in the parts list at the right. Click a part name to see details, price, and add it to cart.
Confirm your model/series and serial number range on the product page. Many manufacturers have serial breaks, when in doubt, share your model and serial with us and we’ll verify fit.
The Ref. # points to the callout on the drawing. Qty shows how many of that item your machine uses. Parts are sold individually unless noted as a kit.
Yes, we supply genuine OEM parts for all our brands. If a part has an approved replacement, we ship the latest superseded revision
Manufacturers often supersede numbers. Our pages list the current orderable number and show older numbers in the description when available. Your old number will cross-reference to the correct part.
Yes. Some items are not pictured or are shared with other assemblies. Send us the model, serial, and a description (or photo) and we’ll locate it.
Yes. DanseUSA passes the manufacturer’s warranty to you. Coverage applies to defects in materials and workmanship under normal use for 30 days from the purchase date, in line with the manufacturer’s warranty policy. Terms can vary by brand; the product page reflects the applicable policy. If a claim is needed, we’ll help coordinate with the manufacturer.
Yes, most new, uninstalled items can be returned under our standard policy. Please see our Returns & Refunds Policy for eligibility, timeframes, and any exceptions.