RX3: Engine Top End Rebuild at 22,450 Miles

[SpudRider]

Installation of RX3 Engine in Motorcycle

Install Engine in Motorcycle

Place Hydraulic jack under Engine
Raise engine into frame
Install swingarm bolt
Install both bolts at rear of engine
Install upper bolts connecting rocker cover to engine frame
Install the two bolts connecting the intake manifold to the cylinder head

Install Clutch Cable, Shift Lever and Hoses from Engine

Install Clutch Cable to Left Crankcase Cover
Install the Oil Contaminant Separator (OCS) on Engine
Install Shift Lever

Install Electrical Connections to Engine

Connect power wire to starter motor
Connect Ground Wire
Connect stator and pickup coil wires
Connect gear indicator wire
Install MAP/MAT Sensor to Intake Manifold
Install Ignition Coil to Frame
Install Spark Plug Boot onto Spark Plug

Install Left Radiator

Install upper hose from Thermostat Housing
Connect fan electrical wire to wiring harness

Install Right Radiator

Install lower hose from water pump on right radiator
Install upper hose to right radiator
Connect fan electrical wire to wiring harness
Install hose from Thermostat Housing to Cylinder Head
Fill radiators with coolant

Install Exhaust Header and Perimeter Engine Bracket

Install lower engine bolt of perimeter engine bracket
Install Radiator Mounting Wings and both top bolts of perimeter engine bracket
Install two bolts on rear of perimeter engine bracket
Install upper engine bolt of perimeter engine bracket

Install Exhaust Header

Install both bolts for both radiators
Install rear brake pedal
Connect wires for auxiliary lights on perimeter engine bracket

Install Fuel Tank

Install fuel tank
Install upper engine guard and connect wires to auxiliary lights
Install fuel tank fairings
Install plastic side covers
Install main saddle
Install pillion saddle

Install Progressive Shock Linkage and Rear Tire

Remove Swingarm Bolt

Install shock link on engine frame
Install Drive Chain on Counter Shaft, and install Swingarm

Install the shock absorber into the frame with the upper bolt

Install the rocker arm onto the swingarm, and torque bolt to 38 foot-pounds

Install Lower Shock Bolt into rocker arm, and torque to 33 foot-pounds

Install rear bolt to link/dogbone, and torque to 38 foot-pounds
Install rear brake caliper onto swingarm
Install Rear Wheel

Replace Motor Oil and Engine Coolant

Install Engine Coolant
Fill Engine with 1.7 Quarts of Motor Oil

[SpudRider]

You must remove the two bolts from the intake manifold before you can remove the engine from the motorcycle. I suggest removing the MAP/T sensor from the intake maifold before you remove these two bolts.

Removing the MAP/T sensor makes it easier to access the two bolts. Also, while the MAP/T sensor is removed, you should clean it with Mass Airflow Sensor Cleaner. Cleaning this sensor periodically will improve engine performance.

http://www.autozone.com/miscellaneou...ner/36011_0_0/

[ElectricCircus]

Thank you Spud : another great RX3 maintenance tutorial!

[SpudRider]

Originally Posted by ElectricCircus

Thank you Spud : another great RX3 maintenance tutorial!

De nada, amigo. Thank you for your kind words.

[SpudRider]

Here is another tip.

The cam sprocket also has a dot in addition to the "L" and "R" markings on the camshaft sprocket. You can see this dot at the 11 o'clock position in the photograph below.



When you install the timing chain on the cam shaft, try to place this dot even with the top of the cylinder head on the right/intake side of the cylinder head. When placed in this manner, the "L" and "R" markings will be placed in the correct vertical locations. If you are satisfied with this alignment, you can apply some black RTV silicon to the cylinder head, and begin the final installation of the rocker cover.

[Weldangrind]

Wonderfully comprehensive tutorial! Of course, I focused on how you welded extensions onto the center stand; have you started a thread about your welder?


I also liked the idea of making a board adapter for your floor jack. I'm going to borrow that mod.


Have you considered non-stock valves? Perhaps there are stainless valves that would fit this engine.

[SpudRider]

Thank you, Weld.

Regarding the welding, I must confess I got lazy. I should have posted, "I coaxed my good friend Andy to weld some extensions onto the center stand." I will go back and correct my post. I did a little stick welding back in the 90's, but I need to get that Eastwood welder you recommend.

The board adapter works very well. It provides a nice, wide and stable platform for lowering, and raising the engine into place. I used it to remove the stock engine, and install a Yamaha XT225 engine in my Zongshen Sierra. The adapter worked equally well with the NC250 engine in my RX3.

I have not confirmed any other valves which fit the NC250 engine. Of course, the problem might also reside with the valve seats. So far, the valve clearances are holding. I hope the new valves and cylinder head have solved the problem.

Incidentally, I also installed four, new valve springs during this engine work. The cam chain was in very good condition, and did not exhibit any elongation, as the timing marks aligned perfectly.

[jbfla]

Thanks for the detailed procedure.

I suspect the intake valves on my RX3 have done the same as yours.....(12.5k miles).

.....the clearances went to zero within 1,000 miles.

Yet, the most recent check revealed the intakes increased by .002".

Is there a way to determine if the valves have receded into the head without disassembling the engine?

Most importantly, what are the options for those of us that don't have the time, skill, tools, work space, or inclination to perform the task?

Has anyone had CSC successfully find them a local mechanic to perform major repairs?

jb

[SpudRider]

Originally Posted by jbfla

Thanks for the detailed procedure. ...

You're welcome, JB.

Originally Posted by jbfla

...I suspect the intake valves on my RX3 have done the same as yours.....(12.5k miles).

.....the clearances went to zero within 1,000 miles.

Yet, the most recent check revealed the intakes increased by .002".

Is there a way to determine if the valves have receded into the head without disassembling the engine?...

My exhaust valve clearances did not stablize until about 16,000 miles. I have never used an inspection camera. Could an inspection camera be employed in this situation? I suspect the size of the spark plug hole, the small area area inside the cylinder, et cetera, might cause problems for an inspection camera. However, I don't know.

I suggest you talk to Gerry at CSC and tell him your maintenance record of how often you did each valve lash check, and the required adjustments. As with me, he might tell you to have a leak down test performed. I bought an OTC 5609, Cylinder Leakage Tester Kit, shown in the link below. It does an excellent job, and I highly recommend it.

http://www.tooltopia.com/otc-tools-5...FQsuaQodCX8J6g



However, be forewarned. Even if your engine passes a leak down test, you still might have valve recession. My cylinder did not leak, but the valve recession was obvious from a visual inspection.

Originally Posted by jbfla

...Most importantly, what are the options for those of us that don't have the time, skill, tools, work space, or inclination to perform the task?

Has anyone had CSC successfully find them a local mechanic to perform major repairs?

jb

Once again, I would call Gerry at CSC and ask for his advice. If you, or anyone else has this problem, he should try to resolve the issue before his warranty expires. That is why I talked to Gerry several times about this problem, and performed a leak down test last fall. This gave me enough time to get authorization to tear down the engine, find the problem, and fix the problem before my warranty coverage expired. Based upon my experience with this problem, I decided to post this thread as a service to the RX3 community.

[jbfla]

Originally Posted by SpudRider

...... I suspect the size of the spark plug hole, the small area area inside the cylinder, et cetera, might cause problems for an inspection......

Your suspicion is correct.

I tried to use my borescope to no avail.....sparkplug hole too small for access.

Got a better view with a LED flashlight and eyeballs.

......... I decided to post this thread as a service to the RX3 community.

Your expertise and willingness to share it, is certainly an asset to all RX3 owners.

And an asset to CSC.....you should be on the payroll....

However, I would wager that when buyers signed up for a "user maintained" motorcycle, they didn't think that included removing the engine, and rebuilding the top end.

jb

[SpudRider]

Originally Posted by jbfla

...Your expertise and willingness to share it, is certainly an asset to all RX3 owners.

And an asset to CSC.....you should be on the payroll....

However, I would wager that when buyers signed up for a "user maintained" motorcycle, they didn't think that included removing the engine, and rebuilding the top end.

jb

Thanks for your kind words, JB.

I'm hoping my experience with this valve recession is a rare occurrence. However, when you mentioned your valve clearances had not stabilized, I felt a moral obligation to warn you, and others, of the possibilities.

I think you might be having other engine problems. I also believe you have some time left on your warranty. I suggest you contact CSC and ask them to help you resolve these issues. If you were nearby, I would certainly help you with the engine work myself. Unfortunately, you live about as far away from Idaho as possible.

[2LZ]

Great write-up Spud! Excellent and complete, as always.

I remember back in the 70's, when unleaded fuel first came out, it was eating up the valve seats and the manufacturers had to go to hardened valve seats. I wonder if this is what's happening here?
Did the old valves look worn or just the seats?

[SpudRider]

Originally Posted by 2LZ

Great write-up Spud! Excellent and complete, as always.

I remember back in the 70's, when unleaded fuel first came out, it was eating up the valve seats and the manufacturers had to go to hardened valve seats. I wonder if this is what's happening here?
Did the old valves look worn or just the seats?

Thank you, 2LZ.

Since the valve recession was obvious, I didn't remove any of the valves for inspection. I wanted to ship the untampered cylinder head to Gerry for his inspection. I also didn't care to do the extra work.

Is unleaded fuel required in China? I don't know. If the Chinese are still using leaded fuel, you might very well be correct. I remember reading somewhere that the Italian company, Piaggio, designed the NC250 engine. I suspect the Italians designed the engine for use with unleaded fuel.

I'm hoping my experience with this problem is a rare exception. However, I felt an obligation to warn others who might be experiencing the same problem.

[2LZ]

Originally Posted by SpudRider

Thank you, 2LZ.

Since the valve recession was obvious, I didn't remove any of the valves for inspection. I wanted to ship the untampered cylinder head to Gerry for his inspection. I also didn't care to do the extra work.

Is unleaded fuel required in China? I don't know. If the Chinese are still using leaded fuel, you might very well be correct. I remember reading somewhere that the Italian company, Piaggio, designed the NC250 engine. I suspect the Italians designed the engine for use with unleaded fuel.

I'm hoping my experience with this problem is a rare exception. However, I felt an obligation to warn others who might be experiencing the same problem.

One more question Spud. Lead did many things including lube the valve seats.....which is why the earlier cars were having trouble without it.

Now....I've never been one to believe in "Miracle in a Can", but I've been running that Lucas fuel treatment that CSC recommended for break in.....just because they recommended it for break-in.

Do you think this stuff really does any good and also, have you been running it in your RX3?

Here's a quote from the Lucas website.

"Lucas Fuel Treatment should definitely be used in vehicles that require leaded fuel because it actually replaces the benefits of lead in gasoline...."

Makes ya wonder.

[SpudRider]

Originally Posted by 2LZ

One more question Spud. Lead did many things including lube the valve seats.....which is why the earlier cars were having trouble without it...

I am certainly old enough to remember leaded fuel; however, I did not know that lead lubricated the valve seats. As usual, you are a wealth of information. Thanks for sharing that interesting fact about lead.

Originally Posted by 2LZ

...Now....I've never been one to believe in "Miracle in a Can", but I've been running that Lucas fuel treatment that CSC recommended for break in.....just because they recommended it for break-in.

Do you think this stuff really does any good and also, have you been running it in your RX3?

Here's a quote from the Lucas website.

"Lucas Fuel Treatment should definitely be used in vehicles that require leaded fuel because it actually replaces the benefits of lead in gasoline...."

Makes ya wonder.

No, I haven't tried any of the Lucas, fuel treatment products; however, I have been thinking about it. Lucas sells several products. I seem to remember that someone, somewhere, recommended the Lucas Upper Cylinder Lubricant. Walmart sells it for $3.83 in the smallest bottle (5.25 ounces).

https://www.walmart.com/ip/Lucas-Oil...ingMethod=p13n



Thanks for raising this issue, 2LZ. I am going to do some research on this topic, and start a new thread regarding it.

I also seem to remember that HumanBeing reported the fuel in China is terrible. If so, one would think that any possible valve face/seat defects would be causing a lot of problems for Chinese owners of the RX3.