2005 CR125 Oil Ratio

Question:

I’ve got a 2005 CR 125. I can’t find out if it’s 2 or 4 stroke. I was told to mix it 4oz. to 1 gal. and now it smokes before it didn’t. WHY??
{Harmon, US – 2005 Honda CR 125}

Answer:

The 2005 CR125 is a two stroke dirt or motocross bike. Two stroke engines differ from four strokes in that they burn oil in the combustion chamber in addition to fuel. There are lots of other differences that have nothing to do with this question. For a really good explanation of the difference between 2 and 4 stroke engines visit What is the Difference Between a Two Stroke and Four Stroke Engine?

The CR125 is a pre-mix type of 2 stroke. It does not have a separate oil reservoir and injector pump. You must pre-mix the oil and gas before adding it to the gas tank. You can check your owner’s manual for the proper ratio. I believe that the Honda CR125 uses a ratio of gasoline to oil that is 32:1. A gallon of gas is 128 ounces. This means you add 4 ounces of oil to each gallon of gas.

There is a lot of discussion about what ratio is best for what bike. If you are going to be competing with this bike, racing or hill climbs, you will want to experiment to find which premix ratio give you the best performance. Older bikes typically use a little more oil to compensate for worn rings or scored cylinder walls. The additional oil helps to increase the compression.

If you will just be doing a little light trail riding on the weekends and will not have it running at high RPMs for an extended period of time, you can reduce the ratio to 50:1. That would mean 2.56 oz of oil for each gallon of gasoline. You can read more about the technical aspects of pre-mix ratios on Maxima Racing Oils website.


If you use standard automotive motor oil your bike will smoke. You need to use 2 stroke oil. Most modern two stroke oils are specially formulated not to smoke. Look for oils that say 2 stroke motorcycle oil, injector oil or smokeless. I put some examples below.

As you can see there are different brands in a range of prices. We use mostly Bel-Ray motorcycle oil products, although PJ1 is another high quality manufacturer.

The advice above is assuming that your 2005 CR125 has stock jetting and exhaust. If the bike has been outfitted with a high performance exhaust or been re-jetted, you may need to adjust the amount of oil you use for peak performance.


Need more free ATV or motorcycle repair information?

Q&A:
Leaking Fuel Valve?

Q&A:
Leaking Gas Valve
flooding engine?

Q&A:
Battery Maintenance

Q&A:
Battery Types

Q&A:
Carb Jetting page 1

Q&A:
Carb Jetting page 2

Q&A:
Aftermarket Exhaust System

Q&A:
Carb Float Needle

Q&A:
Carburetor Identification

Q&A:
Honda Points

Q&A:
Rim Bolt Pattern

Q&A:
CB750F Identification

Q&A: Broken Speedometer Cable End
Q&A:
Suzuki LT-Z400 QuadSport Tank
Removal

Q&A: Motorcycle Trike Conversion
Q&A:
Honda Rancher Reverse Problem

Q&A:
Kawasaki Z650SR Fuel Mix problem

Q&A: RM80 Piston Position

Q&A: LT80 Engine Oil Issues
Q&A:
Clutch Cable Break In period?

Q&A:
Cooling Fan Problem?

Q&A:
1983 XV920 Virago Oil Change

Q&A:
ATC90 Spark Plug question

Q&A:
Nighthawk 750 Spark Plug Gap

Q&A:
Bike Registration Problem

Q&A:
Lost Hypercharger Instructions

Q&A:
Bourget Charging System

Q&A:
Can Spark Plugs be cleaned?

Q&A:
Wheel Bearing Removal for 1976 CB750K

Q&A:
1982 YZ490 Kick Start

Q&A:
1979 GL1000 Goldwing Points Gap

Q&A: 1982 GS650GLZ
Cable Routing Problem

Q&A:
Ether vs. Carb Clean

Q&A:
ATV Ignition Trouble

Q&A:
John Deere backfiring

Q&A:
Honda Phantom 200 Tire Pressure

Q&A:
TRX350 Clutch Slip possible causes

Q&A:
LTF250 Cam Chain Installation & Timing Marks

Q&A:
Demon X pit bike clutch trouble

Q&A:
OK to Increase Tire Size?

Q&A:
RV125 Lost Keys

Q&A:
1981 GPZ550 flywheel cover

Q&A:
2000 Yamaha Badger : Hard to start

Q&A:
1975 CB360T Replacement Tire

Q&A:
Vintage CB750 Chain Size

Q&A:
LTA500F Vinson Leaky Fuel Petcock

Q&A:
TRX350 Rancher Hard Shifting

Q&A:
Replacement Rectifier

Q&A:
GS500F Turn Signals

Q&A:
Suzuki Quad Poor Idle

Q&A:
Yamaha Wolverine cracked Carb top

Q&A:
Vulcan Classic VN1600 Cold Start issues

Q&A:
1980 GS1000 with No Power

Q&A:
High Octane Fuel

Q&A:
Suzuki Bandit 1200 Water in the Oil

Q&A:
Suzuki LT250 Vibration and Clutch Slip

Q&A:
Rancher with Oil in the Air Box

Q&A:
Honda NTV 650 Deauville with Brake Master Cylinder problem

Q&A:
Virago Oil Filter Location

Q&A:
GSX-R1100 with Intermittent Spark

Q&A:
V-Star 1100 Brake Light Wiring

Q&A:
GoldWing 1000 Dyna S Ignition

Q&A:
Honda Trail 90 CT designation?

Q&A:
Yamaha PW50 runs on full throttle only

Q&A:
1996 Virago Oil Filter Cover

Q&A:
’03 Honda Rear Shock Tension

Q&A:
Yamaha XV920MK Virago Exhaust Swap

Q&A:
GSX600 Katana Engine Swap

Q&A:
Vintage CT90 Timing Troubleshooting

Q&A:
Unknown Euro Honda Engine Code

Q&A:
Venezuelan Honda Code = RC09

Q&A:
Virago 750 Throttle Issues

Q&A:
Boulevard C50 Engine Guards

Q&A:
Smoking CR125

 

 

 

 

 

Weeks Motorcycle Home

 

Rate the article:

1 Star2 Stars3 Stars4 Stars5 Stars (Пока оценок нет)
Loading...