Tech Tips
Cost Comparison of the Honda CR125 Stock Moto and ICC / KZ Engine Packages - Part 2
August 27, 2014
In Part 1 of our Stock Moto vs ICC cost comparison, we covered the cost of a complete engine package and covered the top end maintenance costs. In Part 2, we will cover the maintenance cost of the lower end and complete rebuild services, as well as some engine hard parts such as cylinders and cases. (Click Here to Read Part 1)
Again, we need to stress to some that like to scan through these articles, we are using widely published list prices and widely available rebuild interval suggestions. We can spend all day talking about how we can buy an engine cheaper from this online guy or this motorcycle shop, but that is not the point of this article.
To recap, In this article we are going to compare a fully prepped 2001 SwedeTech Honda CR125 Stock Moto package to a Factory Prepped TM KZ10B. For the TM KZ10B, the typical rebuild parts will include a piston, ring, upper bearing, wrist pin, circlips, head o-rings, base gasket(s), lower rod bearing, crank pin, thrust washers, main bearings, main seals, countershaft seal, intake gaskets, and clutch seals. The TM has a crankshaft that can be rebuilt. SwedeTech can usually rebuild the crankshaft 2-3 times before replacing the rod. Parts and Labor for the TM Rebuild service is $895.00 and the recommended interval is approximately 20 gallons of fuel.
The typical rebuild parts for the CR125 will include a piston, ring, upper bearing, wrist pin, circlips, head gasket, base gasket, crankshaft assembly, main bearings, main seals, countershaft seal, clutch seals, intake gaskets, case gaskets, and 4 transmission bearings. Due to the cost of the CR125 crankshaft, the customer has a better product by replacing the complete assembly instead of trying to rebuild it. Parts and Labor for the CR125 Rebuild service is $1120.00 and the recommended interval is approximately 50 gallons of fuel.
Assuming the average kart racer enters 12 events a year and uses 5 gallons of fuel per event, the karter is running 60 gallons of fuel through the engine. These are the same numbers we used in Part 1 of this series.
For a single season of racing, the TM engine will require 3 rebuilds at a total cost of $2685.00. The CR125 engine will require one full rebuild towards the end of the season. If we were to amortize the true cost of the rebuild per year adding in the additional 10 gallons, the CR125 engine will cost $1307.00. Over the course of a season, the CR125 has a $1378.00 savings on normal rebuild labor and parts.
Again, keep in mind we have to make assumptions when it comes to the replacement parts. In this example, we are using the typical rebuild parts. Every engine varies and will have different wear and tear. Some of you might have 4 million gallons on a TM lower rod bearing, but that is not the norm.
To dive deeper into the cost of racing a shifter package, we can assume that at some point, you may seize your engine. Let’s assume the damage is bad enough that you need to repair or replace the cylinder because the plating is damaged. The typical TM cylinder re-finish will cost between 350- 450 dollars. This will include welding the damaged ports, match to original porting, and plating the bore surface. On the high side, the service is $450.00 for the TM cylinder. If the CR125 requires the same service, per the current popular Stock Moto rules, resurfacing of the cylinder is not permitted. You will be required to purchase a new 2001 Prepped cylinder at a cost of $875.00. In this case, the cost savings is in favor of the ICC camp by $425.00.
Another area we need to factor into the cost of each engine is the cases. The TM KZ10B engine has cases that are very durable. In fact, we personally couldn’t place a replacement interval on this part for the TM. It is very infrequent that a TM engine needs a new set of cases, but for the point of this article, we will say the cases will last four racing seasons with normal wear. In contrast, the CR125 cases may only last 2 full race seasons before the bearings start losing a press fit.
The cost of a bare set of CR125 cases is $600.00. Assuming the cases will last two full seasons, you can amortize your seasonal cost at $300.00 per year. TM cases list price is $732.00 and over a 4 season lifespan, your yearly cost is $183.00. That is a cost savings advantage for the TM of $117.00.
We could take this break down and comparison down to carburetors, exhaust pipes, radiators, water pumps, etc., but for the purpose of this article series, we wanted to focus on the expected rebuild and replacement costs for normal wear and tear.
