DR 350 needs some work

[Big T]

I picked up this DR 350 plus 5 other dual sports a few years back in a package deal, because the owner didn't use them anymore and wanted the garage space.

IMG_20190526_122829754 (1) by n, on Flickr

Last fall it rattled to a stop, my buddy with a pickup (who had purchased one of the 6 bikes from me) retrieved it with me and it sat in my garage for months. Now, with plenty of Covid time, I tore it down and found why it no longer turned over

IMG_20200724_211613578 by Tn, on Flickr


IMG_20200724_211644332 by Tn, on Flickr


There are some active forums and a FB page (run by one TKent), so I was able to sort some of the issues out. I had to go to the UK to find a +1 mm piston that wasn't forged and high compression, and that's in transit. I ordered a gasket set from CruzinImage.net, since I've seen many good reviews of their products. I ordered that Sunday evening and it came from Japan this afternoon.

IMG_20200805_214649635 by Tn, on Flickr

Looks pretty nice and complete, down to new copper crush washers for the oil lines. I have a bunch of OEM Suzuki parts on the way also. I'm going to pull the rotor once the puller arrives, then remove the motor and split the cases. I'm wondering what those piston skirts look like.
Once the piston comes next week, off to the boring bar

[Big T]

My flywheel -puller arrived today, along with some parts, including my new piston set. So, I pulled the motor, but ran into 3-4 small issues not mentioned in the factory service manual

IMG_20200810_213503151 by on, on Flickr

I'm searching for the cause and so far nothing definitive. However, I can't help but notice that this motor has been apart before, most notably by the amount of Threebond oozing out of the cases

IMG_20200810_215127657 by To, on Flickr

IMG_20200810_214842577 by [url=https://www.flickr.com/photos/159511674@N04/]T/url], on Flickr

I was referring ton the dirt bike portion of the manual, and therefore overlooked this bolt that the enduros have

IMG_20200810_220704015 by T, on Flickr

Now to research how to split the cases without the factory tool. Running small parts thru the ultrasonic to prepare for assembly. And, crossing my fingers that the machinist will be able to bore my cylinder this month.

My best guess so far is an oil passage clogged with sealant.

[Big T]

Finished spitting the cases today and found all sorts of piston parts inside (big Surprise). Next I will pull the oil pump apart and flush it, if it's not damaged

IMG_20200813_160257185 by Tn, on Flickr

IMG_20200813_160305161 by Tn, on Flickr

The new piston, barrel and head are off to the machinist

[MaurieG]

Nightmare! Hope the oil pump turns out to be usable! I love doing motors like this!

[Rich82GS750TZ]

I picked up this DR 350 plus 5 other dual sports a few years back in a package deal, because the owner didn't use them anymore and wanted the garage space.

IMG_20190526_122829754 (1) by n, on Flickr

I don't think I've ever seen a translucent gas tank on any bike before. Leaves no question about how much fuel you have. That's really cool.

[Big T]

Nightmare! Hope the oil pump turns out to be usable! I love doing motors like this!

Well, I'm lucky enough to have friends with well equipped shops.
I took the right case over Friday and rinsed it in a cleaning sink. Found one piece of grit in oil pump #1, which was locking it up.
Next, the left case, with the trans and crank to the wash sink.
If everything checks out, reassembly of the lower end this week.

IMG_20200817_115015260 by T, on Flickr

IMG_20200817_115001293 by T, on Flickr

[Carter Turk]

Did this happen on the street or out in woods somewhere?

How did you end up splitting the cases, didn't know dirt bikes required a special tool.

[Big T]

Out in the boonies, but just off a road. We drove the pickup within 100 feet. My son pushed it down

The DR was designed as a kick start bike, the kicker was eliminated from the dual sport version. There's still a large place to mount a kick starter in the right engine case, so, a few taps of the plastic mallet and some wedges, and a few taps on some shafts and it came apart. However, the crank is still in the left case it takes one special tool to remove it and another to reinstall. So, it's staying in the case.

I took the left case over to my friends shop and washed it in the safety clean sink

IMG_20200820_165714865_HDR by T, on Flickr

No aluminum bit left in there. The countershaft needed a bit of clean up.

IMG_20200820_092815670 by T, on Flickr

Which was easily accomplished. The piston was removed and showed severe over heating

IMG_20200817_115032593 by T, on Flickr

I'm currently in the process of putting it back together. The FSM is the worst. This is the step by step instructions on how to reinstall the transmission: After you install the main shaft and countershaft, install the shift drum and forks. GRRR

[gustovh]

Nice job Todd.

V

[Big T]

Well, like most old bikes, there's always a good/bad situation
The machinist just called and the exhaust valves are bent. Also, some PO was in there and left a valve spring seat out. How one loses something that big is always a puzzle.

The good news is that the +1 mm bore on the cylinder cleaned up the scuffing and it's ready to install

Ordering parts bow

[dorkburger]

A valve seat?! FFS.

[Big T]

Oops! Valve spring seat

[GS1150Pilot]

I don't think I've ever seen a translucent gas tank on any bike before. Leaves no question about how much fuel you have. That's really cool.

That's old school, Rich. Several of our big Yamahas (the YZ360 and the 490) got those tanks when we decided we wanted more fuel capacity. They ain't pretty, but they're practical and resilient.

[Big T]

Update time - the project has been stalled by bent exhaust valves, me damaging the new cam chain and a cam chain guide that has been back ordered for 3 months. That piece is supposed to arrive tomorrow.

IMG_20200825_224301035 by T, on Flickr

IMG_20200902_113152722 by T, on Flickr

IMG_20200902_134304690 by T, on Flickr

The FSM shows a special tool to hold the con rod, so you can tighten the flywheel nut, primary nut and balancer nut. This chunk of 5/8" marine plywood, with a slot cut in it, did the trick. Thanks to my friend TS, who just restored his utility trailer and had some scraps. With all the side stuff in place and tight, I put the piston and barrel on

IMG_20200925_163236451 by T, on Flickr

The guide goes between the head and the barrel, so it's wait time

[Big T]

The other outstanding issue was the exhaust. The header was stuck in the muffler. The assembly wraps around the frame.so I had to remove the top end, starter, electrics, air box and rear fender to get it off the bike. I have been soaking the joint in Deep Creep for months, and it's still stuck.
My propane torch ruined the paint, but nothing else. So, off to my mechanical genius Jeff, who applied a real torch with the same nonresults. So, we brainstormed, then tinkered. We got the packing to move in the muffler, then about 45 minutes of tapping with a hammer, applying 2 large pipe wrenches to rotate it and many bad words, it moved. And, moved a bit more. Then, I applied vertical force and, bit by bit, it rotated more and moved up. Out it popped. It looks like there was some weird corrosion has it stuck together. Jeff tried grinding off with a variety of abrasives and we ended up with this

IMG_20201007_224234193 by T, on Flickr

It's that black stuff at top left, it goes around the back. This morning I wire wheeled it and polished it with emery. Prime and paint is underway

IMG_20201007_224220729 by Tn, on Flickr

Our work wouldn't be possible without this cool pipe attachment for his middle sized vise. There's no way we could have applied the amount of brute force required without it.

IMG_20201007_224250762 by Tn, on Flickr