I’ve been spinning wrenches for years, prodding a slew of derelicts again into movement since earlier than I might legally drive. In some way, in all that point, I’ve by no means rebuilt an engine. I’ve pulled them and swapped them, changed heads, cams, and transmissions, however by no means damaged one all the way down to its a whole bunch of particular person elements and put all of it again collectively. That modified when my newly acquired Suzuki DR-Z400SM despatched a valve by way of its piston, launching shrapnel into the crankcase.
To make issues worse, I didn’t have a storage or a store. The bikes and my instruments shared house in a tiny, unheated backyard shed a brief stroll from the home. However there was a workbench, electrical energy, and sufficient room to scoot across the DR-Z’s now empty body if I rolled two different machines outside. The miracle of the motorbike is that it takes up no house, you could sew one collectively within the sq. footage of a queen-sized mattress. I’d be becoming a member of the military of fools who’ve assembled bikes in kitchens and bedrooms, basements, and, sure, sheds.
I’d aimed to get the factor executed for lower than the price of a brand new DR-Z, and possibly it will have been doable if I already owned the arsenal of specialty instruments bikes require. I raided Rocky Mountain ATV for slide hammers, case splitters, crank pullers, and clutch pliers. And, as a result of I’m an fool who didn’t need his freshly rebuilt engine to seem like it’d spent its life submerged in West Virginia mud, I ordered up all method of fasteners and new case covers to exchange the corroded manufacturing facility bits, plus each bearing and seal. You’re not dwelling till you’re on a first-name foundation along with your UPS driver.
The meat of the construct arrived in a single huge field, courtesy of eBay: a Cylinder Works 469cc backside finish rebuild, full with a stroker crank, a big-bore cylinder, head and base gaskets, and crank bearings. I additionally picked up a used head from a DR-Z400E, however the greatest hitch was ready for my cams. There are off-the-shelf choices out there, however making dependable energy right here appears to hinge on a cam with sufficient length. I despatched my previous bits off to Internet Cam, and waited 5 weeks for my customized grind to return again.
There was loads to do whereas I waited, disassembling each final little bit of the engine and thoroughly cataloging it in labeled Ziplocs. Previous expertise had taught me to take as many photographs as I might. Irrespective of how good your service handbook, there are at all times issues hidden within the exploded diagrams, orders of operations, tiny springs, or test balls that present up as a smear on the web page and get forgotten when it comes time to reassemble the whole lot.
After I lastly separated the instances, it was clear simply how a lot steel the valve had despatched south. There have been shavings and chunks in each bearing. If I’d simply changed the piston and head and hoped for the most effective, the bike would have been aside once more in below a month. For the primary time since I introduced the bike residence, it felt like I’d made an accurate choice by going for the total teardown.
The instances have been filthy, corroded, and oily from years of neglect. I gave them an excellent scrubbing with gasoline, then aluminum magazine cleaner earlier than bringing them to a buddy’s for soda blasting. They got here out trying model new.
In the meantime, one other thought started scratching behind my cranium. The gearbox on the DR-Z has at all times been a sore spot for me, with first being too lengthy for technical trails and fifth too quick for freeway obligation. The factor has at all times felt prefer it wanted a sixth gear. There aren’t any conversions that can add one other cog to the combo, however ACT has been promoting a wide-ratio equipment for years. ACT is nicely regarded, with few, if any complaints. At $620, the swap isn’t low cost, and it requires just a few modifications to each the case and the shift forks. Nonetheless, I might see a future the place I went by way of all this effort to construct a DR-Z with 20 extra horsepower than manufacturing facility solely to be extra annoyed by the bike’s gearing.
If I used to be going to experiment with a wide-ratio DR-Z, now was the time. Add “rebuilding a transmission” to the listing of issues I’ve by no means executed earlier than. There’s one thing that occurs when you’ve got each final piece of a machine aside and in your palms. You perceive for the primary time how not possible the factor appears. How fragile. How a thousand elements have to be assembled simply so to ensure that the factor to perform in any respect. The miracle of the machine.
Weirdly, it was the wide-ratio swap that gave me probably the most bother. ACT will promote you pre-modified shift forks, however as a result of I’m an fool who owns extra grinders than , I figured I might deal with the work alone. That call meant the gearbox was seized tight the primary thrice I assembled the instances. After a irritating quantity of grinding, cleansing, meeting, and disassembly, I had the instances glued and bolted again along with the transmission shifting because it ought to.
An engine is overwhelming when taken as a complete. There are such a lot of items to doubtlessly neglect, so many techniques inside techniques, that simply getting began may be paralyzing. The excellent news is, you’ll be able to’t come at it all of sudden. It received’t allow you to. It needs to be taken bolt by bolt, simply as a 12 months have to be taken minute by minute, daily. There aren’t any shortcuts.
It took three months of working on and off at night time and over weekends to get the engine collectively and again within the bike. Not one of the dudes on the native store needs to be frightened about job safety. It had been so lengthy that I had forgotten how good the factor appeared as one thing apart from an empty body.
I poured contemporary gasoline within the tank, made certain the battery was charged, and hit the ignition. Need to expertise your entire spectrum of human emotion within the span of some revolutions? Strive beginning an engine you’ve simply rebuilt in a shed. The massive single-cylinder churned as soon as, twice, and fired, blatting its resurrection on the neighbors. It might be days earlier than I might journey the factor. I needed to undergo a punishing break-in process, full with different rpm and re-torquing the top bolts at specified intervals. An early oil change to swish out any bits of particles left within the engine. However it was executed. Collectively. Full, and, I hoped, higher than it had ever been.