Classic Motorcycle Build

DIY vs Machine Shop

Should you farm out your engine work to a local shop or do it yourself? If you have past mechanical experience and are willing to devote the time and invest in tools, rebuilding a motorcycle engine yourself may be the better choice.

motorcycle engine build diy vs machine shop

Rely On Your Own Work

It's frustrating that some alleged "professional", who never puts a micrometer to a valve stem, or a bore gauge in a cylinder, will say, "You need an engine build".

His reasoning? "Because the bike is old".

How do you know if they're wrong or right? At a minimum, you should be able to check it for yourself.

Since 2007, the shop that I have known and trusted is now five states away. To ship parts there and back would get expensive. It also exposes parts to damage if not packed and shipped properly.

Out of necessity, I started learning new skills and acquiring specialty tools as I have needed them. Today, I can perform nearly every aspect of motorcycle engine rebuilding. It is a time-consuming process, but it's a good feeling to control an entire project from start to finish.

Why I Don't Trust Machine Shops

Machining costs always seem reasonable at first, but are likely to change. They may quote you low to get the job in the shop, then sell you other services along the way. Some of this is honest, but some of it is not.

Consider their precision tools that a machine shop uses day in and day out, are they ever checked and recalibrated? The difference of a thousandth of an inch on lower-end clearance is critical. It could mean the difference between a 50,000 mile engine or a 10,000 mile engine.

diy vs machine shop

Motorcycle Engine Tools

The money you save by doing it yourself gives you a bigger budget to buy tools you need, and rebuilding a motorcycle engine will require specialty tools. If you don't have the required tools, you can buy them new or used, but many of them you can make yourself. Depending on how creative you are, many can be fabricated.

Read: Motorcycle Engine Tools

I've heard of more than a few riders with negative (and expensive) dealings outsourcing their engine work.

Shipping A Motorcycle Engine

There will always be shops that work on vintage bikes, I'm sure there's dozens of reputable shops in the U.S. alone. But will they be in driving distance of your home? If not, factor in another $350-$500 for shipping (there and back).

Some tips on finding a shop that will be reputable, dependable, reasonably priced, and familiar with vintage engines:

If you don't know of anyone who's used their services, read online reviews about them.

Make sure you specify everything that you need to have done, and leave no room for interpretation.

Don’t assume anything - get all service work to be performed in writing BEFORE starting.

Remember that "professional" is NOT a skill level, it only indicates compensation.

motorcycle engine diy vs machine shop

Is rebuilding a motorcycle engine something that can be done in your home garage? Yes, but first you should understand the how and the why. This is done by reading everything you can on the subject. Of course results will vary, but one thing is certain - your results will likely be far better than a machinist who doesn't care.

motorcycle cylinder boring

Read: DIY Motorcycle Cylinder Boring

diy vs machine shop

Read: How To Measure And Remove Valve Guides

assemble Harley-Davidson 45 flathead cylinders

Read: How To Lap Valves