Makita EK7650H, EK7651H dimensions Oil ring, Assembling Engine Block

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Repair

[4]DISASSEMBLY/ASSEMBLY

[4]-8. Engine (cont.)

ASSEMBLING ENGINE BLOCK

Note: Be sure to apply Makita grease N No.2/ 4-cycle engine oil in accordance with [3] LUBRICANT APPLICATION.

(1)Connect Piston with Crankshaft complete by inserting Piston pin into place; there is no front/back to Piston.

(2)Secure Piston pin by mounting Ring spring 12 onto each end of Piston pin.

Note: The ring gap of Ring spring 12 can be positioned at any angle to Piston pin.

(3)Install Oil ring in the grooves of Piston; Side rail first, Spacer next, then the other Side rail.

Important: Be sure to fit the three rings with the ring gaps at 120 degrees to one another as shown in the left of Fig. 63.

(4)Install Second ring first then Top ring in the groove of Piston.

Important 1: Be sure to fit the two rings with the ring gaps at 180 degrees to each other as shown in the right of Fig. 63.

Important 2: Second ring has a taper face and must be installed with the large diameter facing Oil ring. (Fig. 64)

Distinguishing between Top ring and Second ring & Discriminating the larger diameter of Second ring: If both of the two rings are new and unused,

You can distinguish from their appearances; there is a red marking on the side face of Second ring as shown in Fig. 65 while not on the side face of Top ring.

You can face the large diameter of Second ring by placing Second ring with the red marking on your right and with the ring gap near you as shown in Fig. 65.

If both of the two rings are used and the white marking of Second ring is rubbed off, carefully press the side face of the two rings to the inner wall surface of Cylinder. You will be able to distinguish the two rings or to discriminate the large diameter of Second ring through the differences in contact feelings that the different side faces make.

(4) Remove oil/grease from the mating surface of Cylinder block and Crankcase.

Then apply ThreeBond 1215 to the mating surface of Crankcase as shown in Fig. 66. Note: ThreeBond 1215 must not be applied to Oil supply routes.

Apply 4-cycle engine oil to the cylinder portion of Cylinder block, and then while compressing Piston rings, mount Cylinder block onto Crankcase.

(6)Tighten eleven Hexalobular socket head bolts in a crisscross pattern. (Refer to Fig. 58.)

(7)Do not forget to set Exhaust port spacer in place on Muffler installation side of Cylinder head complete. (Fig. 67)

Fig. 63

 

Oil ring

 

ring gap

 

ring gap

 

 

 

 

Side rail

 

 

Top ring

 

 

Second ring

 

 

 

Spacer

 

 

ring gap

 

 

 

Side rail

 

 

This mark can be

ring gap

 

 

ignored for

 

 

assembling

 

 

 

 

 

ring gap

EK7650H/ EK7651H.

 

 

 

Fig. 64

 

Fig. 65

 

Top ring,

 

with barrel face

Second ring,

 

with taper face

Side rail

 

Spacer

Oil ring

Side rail

 

Fig. 66 [Crankcase viewed from top]

Second ring

red marking

Fig. 67

Portion to apply

Cylinder head complete

 

ThreeBond:

 

indicated in gray

Exhaust port spacer

Oil supply routes

 

Image 17
Contents Standard equipment SpecificationOptional accessories Repair Necessary Repairing ToolsLUBRICANT/ Adhesive Application EpairDisassembling Belt 5-800, Cutting deviceAssembling Starter assembly Clutch, Ratchet Disassembling Flywheel Complete Adjustment the GAP Between Ignition Coil and FlywheelFlywheel, Ignition coil Disassembling Ignition Coil Carburetor Adjustment of Carburetor After Replacement Engine block Throttle leverDISASSEMBLY/ASSEMBLY 4-7. Engine block Engine Arm has to be close to Repair Assembling Engine Block Oil ringLead unit DISASSEMBLY/ASSEMBLY 4-8. EngineChecking Spark Plug Tightening torque specificationsIgnition system

EK7650H, EK7651H specifications

The Makita EK7650H and EK7651H are robust and powerful cut-off saws designed for professional contractors and construction workers. These models are ideal for cutting through concrete, masonry, asphalt, and other tough materials with precision and efficiency. Their advanced engineering and innovative features set them apart in the competitive landscape of power tools.

One of the standout features of both models is the 4-stroke engine technology, which provides a significant reduction in emissions and noise compared to traditional 2-stroke engines. This makes them environmentally friendly while also allowing for longer operating times without the need for frequent fuel refills. The powerful 6.6 HP engine delivers exceptional cutting performance, enabling users to tackle even the most challenging jobs.

The EK7650H and EK7651H are equipped with a “Fast Start” technology that allows for easy starting, reducing the effort required to get the saw up and running. This is especially useful for users who need to work quickly and efficiently on-site. Additionally, the saws feature an automatic choke that enhances starting reliability in various weather conditions.

Comfort and usability are central to the design of these models. The dual anti-vibration technology minimizes vibrations during operation, significantly reducing user fatigue. The ergonomic handle provides a secure grip, allowing for greater control during cutting tasks. This is particularly beneficial for prolonged use in demanding work environments.

Another key characteristic of the Makita EK7650H and EK7651H is their versatility. They are designed to accommodate various blade sizes, which gives users flexibility in choosing the right blade for specific applications. The saws also feature an integrated dust management system that helps keep the work area clean, enhancing visibility and safety.

Both models come with an adjustable cutting depth feature, enabling users to achieve precise cuts for various materials. The easy-to-access air filter and fuel system ensure simple maintenance, extending the life of the saws.

In summary, the Makita EK7650H and EK7651H are powerful, efficient, and user-friendly cut-off saws that cater to the needs of professional users. With their advanced features, including a 4-stroke engine, ergonomic design, and versatility in blade sizes, these saws are indispensable tools for anyone looking to perform cutting tasks with precision and ease.