Honda CR125 - What else for I need to make it run?

[Cesar Rull]

I am exploring some options on motors packages as well as just buying a motor and building my own package and I have some questions regarding this.

I know that I will need a carburetor but I am unsure what type is it that I need to run for a cr125.

Additionally, I will need a fuel pump, can I also please get some recommendations of this?

Do I need to get a water pump as well? or are these included in the motor?
Besides a pipe and silencer (I have gathered that RVL stuff is what most people run) - yet I am open to less costly options. What else do I need to install it on a kart and make run besides a radiator?.


These are the items I have been able to identify I would need:

Motor Moutn
RVL R4 Pipe
RVL Silencer
Carburator
Filter
Fuel Pump
Water pump?
Exhaust Mounting Kit

I appreciate the help, thank you.

[Tim Salvino]

I would not suggest trying to buy each individual piece. Complete packages with EVERYTHING you need are easy to find, and save you the hassle of buying each individual part, then forgetting something and having to wait another week or so to get it in....


If you want to know what all you need, just read the descriptions for the packages.

http://www.shopswedetech.com/SKUSA_Stock_Moto_S1_S4_classes_p/cr125%20comp%20no%20rad.htm

http://www.msquaredkarting.com/store/gearjammer_stockmoto.htm

http://www.extremegokarts.com/honda-cr125-stock-moto-complete-engine-package-p-3.html

http://sharkshifter.com/zc/index.php?main_page=product_info&cPath=90_91&products_id=1387

[Troy V Smith]

For the carb, you are looking for a Keihin PWM or PWK 38mm. Obviously, the needles, slides and such may be dependent upon your location.

For the fuel pump, I use, and I think the most popular choice is the Mikuni round style fuel pump which has the pulse, an inlet, and two outlet fittings.

Some may point you in the direction of a "pump around" mod which will require a modified carb and a twin fuel pump - but if you are just looking at getting things up and going, I wouldn't be concerned with the pump around stuff - I've tried it and never saw the advantage over a good working carb.

Water pump is internal on the CR125.

Exhaust mount kit will be dependant upon the pipe you choose, but I have found the Hegar exhaust mount kits to be my preferance.

Hope that helps...
_________________
TVS Motorsports -
"We may not be the fastest on the track...
but we're having the most FUN!"

[Cesar Rull]

Thanks Troy. - yeah I don't need the pump around stuff.
Are both carbs models the same just different brand? - when I buy a carb, I also need to order the slides and needle separately? - there is a motocross shop I can go into which should have these parts.

@Tim for someone reason all those packages which I have looked at are 500+ more expensive that the package I can piece together. I have all the time in the world really so I don't waiting and learning. This car will probably not run until Dec. because of budget and other reasons.

I want to take my time as much as I want this running tomorrow.

[Cesar Rull]

I noticed that SS has:

http://sharkshifter.com/zc/index.php?main_page=product_info&cPath=90_91&products_id=187

compared to this which makes my package cheaper:

http://www.extremegokarts.com/honda-cr-125-stock-moto-engine-p-2.html?cPath=1

There is also this:
http://www.extremegokarts.com/honda-cr125-stock-moto-engine-free-swedetech-engine-mount-p-226.html?cPath=1

The item above is a little more money but it does mention "Slip fit and true crank" and a "free" motor mount.

Is that really the difference in price, the "Slip fit and true crank"? - from some of my reading the fact that is slip and fit will make replacing the crank much easier in the future? - what is the advantage. Is this really worth the extra money

[Tim Salvino]

Here is as complete of a list as i can compile right now:

1999 Honda CR125 Engine with stock electrics(stator, CDI, coil), reed cage, intake manifold
Keihin 38mm PWK or PWM (same manufacture, same size, different models)
K&N Air Filter, or Air Box
Air Filter/Air Box support (Hegar brand is great)
Exhaust Manifold (2, 3, or 4 o-ring types)
RLV R2 or R4 Exhaust Pipe
Exhaust silencer (many different brands and models. The current 'hot' one is the new swedetech silencer)
Exhaust pipe/silencer supports (Hegar brand is great)
Motor Mount (Many different brands, Swedetech makes the lightest and most adjustable one)
Engine Sprocket 14-19 tooth(most all shops have them. some charge more than others)
Chain 428 (most all shops carry 428 chain)
Fuel Pump (Mikuni round, or Dellorto square, or dual Mikuni rounds if you are running a pump-around system)
Power Valve Plugs (can be bought as blanks, or pre-blended from some suppliers)
Power Valve cavity covers (not necessary, but make the engine look cleaner. Available many places)
Clutch Cable (Swedetech makes a VERY nice, heavy duty adjustable one. But it's not cheap...)
Fuel Line (1/4" or 10mm. Sold by the foot. Buy at least 5 feet)
Throttle Cable (nothing special here, just make sure it has the correct end for the carb, and is long enough for the kart)
Radiator/Coolant hoses (you can throw something together from auto parts store, or buy the new 'trick' silicon 2-into-1 hose)
Exhaust springs (to secure pipe to manifold, and silencer to pipe)
Hose clamps (for coolant hoses, and also fuel lines)
Fuel Filter (personal preference)
Axle Sprocket 20-30 tooth (available at most kart shops)



I'm pretty sure i missed a few things...
But that is a list of all the odds-and-ends that you will need just to get it on your kart. That doesnt include extra jets/needles for tuning, or throttle and clutch cable clamps, or many other things you will need for a complete running kart. Dont forget your Radiator and mounts!!

Good Luck!

[Troy V Smith]

[Cesar Rull]

What is this slip fit service some of these companies advertise ?
How does it affect then motor or servicesavility ?

[Tim Salvino]

http://lmgtfy.com/?q=crank+slip+fit


If you read the first link to come up:

"This crank has been machined to "slip fit" inside the crank bearings. From the factory, Honda uses an interference fit between the crankshaft and crank bearing. To slip fit a crank, you can have a machine shop turn it slowly in a lathe or you can do it yourself with emery cloth. Setting up a crank for a slip fit makes assembly and disassembly much easier."

[Cesar Rull]

Well what happens when I get another crank in the future?
I will need to take the crank and case to machine shop again and have them fit the new crank wouldn't I ?

I still don't understand the advantage, its not like people open the bottom of their motors on a regular basis do they?

[Tim Salvino]

[Jeff DeMello]

I would keep the stock bearing and use a slip fit crank. I buy my cranks from Shark Shifter
_________________
Jeff DeMello
Emmick F125 Pavesi

[Cesar Rull]

Jeff, so when you buy a replacement Crank do you also order the bearings from SS? I am assuming you open the case at home order a replacement online?

I am trying to understand how is it that you ensure the new crank you get will slide and fit into your current bearing when ordering from SS?

Thank you.

[Troy V Smith]

Cesar - I slip fit the crank as well - using the stock bearings. You can "slip fit" the crank yourself without the use of a machine shop. Emery cloth on the crank journels works just fine - been doing mine that way with no issues. May not need to pull the bottom end apart very often, but when you do - a "slip fit" now will save you countless aggravations later!
_________________
TVS Motorsports -
"We may not be the fastest on the track...
but we're having the most FUN!"

[Cesar Rull]

anyone know about the guys are extremegokarts.com ?
are they ok to buy an engine from?

I am leaning towards:
http://www.extremegokarts.com/honda-cr-125-stock-moto-engine-p-2.html?cPath=1