Thoughts on a 2-stroke

#1
Hi there, just found Expedition Portal the other day and this site is great, Me and my family (Wife and 4 kids) love exploring and take every chance we can to get out. That being said, I was just given a old 79' Yamaha YZ-400-F, it's a 2-stroke dirt bike. With a price of free I couldn't turn it away, and adventure biking has always been something I have been interested in but not really something you can do as a family of six. It needs quite a bit of work to get it running and usable. At a minimum I am going to clean it up, get it running and sell it, but I got to thinking about turning it into something I could take by itself or load it on the back of our suburban for some extra range when we go to the mountains. Obviously a 2-stroke is going to be more involved in taking on long distant trips, fuel is just going to take a few more steps, but is this is big deal, or am I overthinking it? Second, this bike is more of a dirt bike, and while I really like the idea of fixing up a vintage bike, am I just getting myself off on the wrong foot trying to use a bike like this? Thanks!
 
#2
Put a little work into the bike and give it a try on your next trip to the mountains.

Assuming is runs well and is mechanically sound, mixing fuel is easy and not a hassle.

My guess is that the biggest potential problem you'll have is that the YZ400 is a purpose built motocross bike. It has a big motor by two stroke standards and probably has a power curve that looks like the Eiffel tower. Not any easygoing bike that likes cruising on trails and exploring. But great if you want a big hit when the power comes on.

Good luck

R
 
#3
That's what I have heard and read. I have ridden street bikes for the last year or so, but my off-road time is pretty limited so I think there will be a learning curve. A power band like that doesn't seem like it would be great for climbing technical trails either.
 

haven

Expedition Leader
#4
Check to make sure your exhaust has a spark arrestor. They are required these days, and may not have been back in the 1970s. We don't need any more wild lands burned up this year.
 
#5
Don't know where you live, but some places make it rather hard to get a plate for a bike that was never meant for the street.

Getting fuel/oil isn't a big deal as most gas stations still sell two stroke oil, and older two strokes run better on the cheap oil. I use the cheap gallon bottle stuff from Wally World when at home and whatever is available when I travel. My farthest trip on my KE100 to date was from Chicago to the Deals Gap (NW N Carolina).

If you can find a heavier flywheel for it, that would help to smooth out the band and make it better on the trails.
 
#6
@haven That is a good point I hadn't considered. I'll have to check that out and if it doesn't add one. I am in the Central Valley of California so we have had our fair share of wildland fires in the sierras above us. Pretty nasty actually because all the smoke comes down off the mountains and just hangs out in the valley.


Don't know where you live, but some places make it rather hard to get a plate for a bike that was never meant for the street.

Getting fuel/oil isn't a big deal as most gas stations still sell two stroke oil, and older two strokes run better on the cheap oil. I use the cheap gallon bottle stuff from Wally World when at home and whatever is available when I travel. My farthest trip on my KE100 to date was from Chicago to the Deals Gap (NW N Carolina).

If you can find a heavier flywheel for it, that would help to smooth out the band and make it better on the trails.
Being in CA I have heard it's not a huge deal to get the bike road legal, but I haven't done it yet so I don't actually know. So is the flywheel being heavier just slow down how fast the engine can rev up?
 
#7
Back in the good ole days I had a couple of 2 stroke bikes. One was a street legal Kawasaki 350 with a compression release, the other was an old YZ that would kick back if it wasn't started correctly. Both were great fun off road, the Kaw was ok for getting to the off road trails.

Those old thumpers were fun!
 
#10
I'll get it running and re-evaluate from there. It is looking like it will be enough work just to get it running, and this thing was never meant to be a road bike. Looking forward to it as a project though, I like old stuff.

Sent from my SAMSUNG-SM-G900A using Tapatalk
 
#11
Buddy of mine just restored a Yammie 175 Enduro, it took 3 other parts bikes to do so.

Kinda cool to plunk around on it, it also makes you realize how far we have come from the Good Ol' Days.

Not sure if they still make them for your application, Cobra makes clamp on spark arrester.

 
#12
My personal experience was never good with the 2-strokes, because they like to be ran wide-open all the time. I always fouled plugs from lugging it around slow. So if your not riding it hard I would get a four stroke.
 
#13
My personal experience was never good with the 2-strokes, because they like to be ran wide-open all the time. I always fouled plugs from lugging it around slow. So if your not riding it hard I would get a four stroke.
The old ones yes, modern versions are much better...you can lug them all day long. My 300 is like a tractor.
 
#14
The old ones yes, modern versions are much better...you can lug them all day long. My 300 is like a tractor.
That's good to hear. My first bike was a CR125, I think the first year of the aluminum frame maybe 1996? Anyways, you had to run it like wide open or it didn't like it. Not good for a 17 year old kid just learning how to ride on trails. Didn't take me long to convert to 4 wheels.
 
#15
Lots of 2T street bikes/enduros out there, but with this particular bike my concerns would be the vibration on the street (big bore 2T = paint shaker), fuel range (maybe 40 miles if I was to guess) and difficulty powering a decent headlight.

Anything is possible I just think if you're okay with riding an older bike there are much better options available (Honda XL, Yamaha XT etc..)