motorbike: Rebuilding a Honda Dirt Bike from 1984

Started: 2022-10-26 - Last updated: 2023-11-09

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Feeling nostalgic from thinking back to working on a truck in highschool, one Saturday, I searched KSL (Utah's Craigslist) for a simple, nimble motorcycle that I could build into a commuter. I ended up finding a restoration project that someone was done with for $500. After spending all day trying to decide if it was worth the cost, I decided to set a $2,000 budget and see whose car I could borrow to make the 256 mile trip to and from Smithfield Utah. The next day, I was able to borrow a car (Thanks Grandma!) and by Sunday night, I had 99% of the parts needed to build a dirt bike.

I was beyond excited for this project so I ordered a shop manual and seat cover so I could get started as soon as possible.

While I'm waiting for the shop manual to arrive in the mail, let's work on the frame.

Before we can paint it, I had to figure out how to weld a small area near the back of the frame. (The real structural parts are in great condition)

Not knowing how to weld, I decided to offer students on their way out of a welding class $20 for fixing part of the frame. Carlos Ruiz was awesome and did a great job welding it back together.

Next, I need to figure out how to paint the frame. I'm hoping to use UVU's expensive automotive painting tools but we'll see.

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The Professors over the painting equipment at UVU referred me around and others just ignored me for a month. So I decided to paint the frame myself one Friday. After a trip to Walmart for supplies, I spent the rest of the night painting in the shower because it was too cold for the paint to properly adhere outside.

[Note: I do NOT recommend spray painting indoors. It was terrible and not something I would do again. There was so much pink dust everywhere.]

The next day and $35 later, I had a nice painted frame. I had also added spray foam to the worn parts of the seat.

This brings the total cost of the project to $714.58. The seat and suspension are likely the next items I'll work on.

Welp, I failed to staple the seat cover and mounting the new tires. I could not find a stapler that would properly go through the seat plastic and not poke through the outside fabric. So I'm giving up work on the seat for now. As for changing the tires, I pinched a hole in the front tube while mounting it. I could not even get the old tire off the rear rim so I decided to just pay a motorcycle shop to deal with the tires. Forward movement on a project is good even if that means you pay someone else to do the work.

Thankfully, I'm having more success with the suspension. The fork came apart easy enough and it should not be too hard to put back together. I'm just waiting on a foam "grease holder" ring to be shipped because the one in my fork falls apart to the touch.

The rear suspension is now completely put together. Special thanks to Steve for the grease gun and Chris for holding the rear swingarm in place so I could put the bolt through :)

And now I'm at the part I've been dreading: the motor. In the original listing for this bike, it says the stator might have overheated and died. Or the rectifier was unplugged. Fortunately, everything seems to look good given the situation. The shifter feels good and I can find neutral easily.

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Building this bike is a lot like building a lego set. Except that the manual shows how to disassemble the engine. Let's hope I picked the right 3 bolts for this step lol.

With the upper valve section in place, I should be able to run the timing chain. To do this, I need to unscrew the 2 aluminum caps on the lower part of the motor so I can see the marker and line up the piston and valve position. Unfortunately I'm bending quarters trying to remove the upper cap. So that's the next task I'll procrastinate on.

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Anyway, now is a good time to review the money spent and hope it is a low number lol.

• Paint, gas, and buying the bike (outlined more above) $714.58
• Fork seals (crappy chinese clone), fork boots, brake pads/shoes $58.72
• Tires, tubes, tire irons, bolt kit, rim strips $269.20
• Screw extractor, ATF fluid for the fork, paper towels/wipes $26.48
• Tire change and balance at the shop $61.99
• OEM Honda fork seals, 6MM nut $54.86
• Gasket kit, replacement steering stem $79.18
• donation to GATE because ebay made it easy to give $1

Up to this point, I've spent $1,265.01 :/

I originally set a budget of $2,000 but that's because I could justify the cost of building the dirt bike so I would be able to commute from a cheaper apartment farther from campus. But I'm now in my last year of university and already signed a lease on a closer apartment. So I'm probably going to sell the bike.

I've put in so much effort that I want to reach the milestone of having the bike running rolling.

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It has been a month since my last post and there is no way I can get the bike running in time unless I pay someone else to fix it for me. And that would easily cost more than the rest of the remaining budget ($734.99). I'm also finishing a number of software projects and classes next month. And once all that is over, I'll be taking 19 credits for my last year of university.

So I've decided to sell the bike.

I did make a last bit of progress on the since last month. Motogrugals finished replacing the fork seals/fluid and I got help fom Melaine (Thanks!) with the [yet another] unexpectedly difficult task of putting them on the bike.

I really don't want to give up on this project. I just can't justify moving forward with it knowing that it will take a lot of time and money away from better learning opportunities. At least this project helps me find my limits so I can make better decisions about projects in the future.

I'm still going to finish a motorized bike build someday. (This is not my first attempt) I just know that I will need more time/money since they always seem to be more expensive and time consuming than expected.

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I ended up selling the bike and tools I bought for the project to a high school student and his dad for $500. Hopefully he has more luck than I did :)

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It's February 2024 and I finally have a functional motorbike!!