Two stroke as an adventure bike

Discussion in '2 smokers' started by Shawnspeed, Apr 19, 2017.

  1. Shawnspeed

    Shawnspeed Been here awhile

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  2. Branchbuster

    Branchbuster Long timer

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  3. ErikMotoMan

    ErikMotoMan Airbag crash survivor!

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    I ran a Yamaha wr 250 as a dual sport bike for many years back in the 90's. Fuel burn was the biggest problem
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  4. wfopete

    wfopete Suffer Fools; Gladly!

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  5. porterrad

    porterrad Been here awhile

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    Used to run my retired 2 stroke enduro race bikes as "adventure" bikes in the 70s & 80s. It was easy to tag most anything in some states back then. Lights on all of these bikes were pretty dim, so they were pretty bad for nite riding. However, my biggest problems on tbe highway were brakes & fear of seizures going down long hills. I seized on the highway descending from Mt Lake in Virginia. After that, I'd always pull in the clutch occasionally & rev the engine to add some oil to the cylinder. Never seized going downhill again, but it was always a concern.

    Adapted a disc from a Honda street bike to improve the brakes, but never got over the fear of a downhill seizure - particularly in traffic.

    Occasionally, when trying to mix oil in the tank at gas stations, the oil would sink to the bottom of the tank & clog the petcock. When this happened, I usually had a helluva time unclogging it without gas getting everywhere.

    The best 2 stroke adventure bike I ever had was a '74 Maico 400 Enduro. This bike had a wide ratio 4 speed, a pretty big gas tank & a relatively wide seat towards the back. When geared tall, this bike was fast, pretty smooth & got pretty good fuel mileage. A few years later, I thought my Husky WR390 would be a better adventure bike due to the wide ratio 6 speed, but it vibrated much more than the Maico & didn't get nearly as good fuel mileage.
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  6. Eatmore Mudd

    Eatmore Mudd Mischief on wheels.

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    They are fun and I wouldn't turn down another Suzuki GT-750 if it came my way but poor fuel economy, needing to carry oil, narrow power band, lack of engine braking and accelerated piston ring wear were the main reasons I quit two strokes early on for my riding.
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  7. JensEskildsen

    JensEskildsen Long timer

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    I've used my little yamaha dt125r as a daily adventurebike, and for a single weekendtrip with 2 nights in a tent.
    I've attended trips with a lot of bigger dualsports, the bike will keep up just fine.
    Cruising at 50mph / 80km/h I'll get around 45mpg or 20km/ltr. Together with 1,1ltr oil-reservoir, the 2 stroke part is not an issue.

    Siezing the engine is still in the back of my mind, I think thats form my yonger days on mopeds...
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  8. stucknarut

    stucknarut Uh oh...

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    I've done some limited sport touring on my RD350 (800-1000 mile weekend camping trips) and it is small and light enough to handle gravel roads fine. But fuel range is a big problem, and it's really only fun and happy at speed. I briefly considered a 1978 KTM 400 with an enduro kit as an adventure bike, had a big plastic tank and was a horse. But honestly, my DR350 will do the same thing and be less of a smelly pain in the ass.
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  9. jimroid

    jimroid Long timer

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    IMG_5261.JPG Two-stroke adventuring? Hmm, I guess it can be done. IMG_5247.JPG
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  10. MATTY

    MATTY BORDER RAIDER

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    Fuel Consumption is the obvious one here, the Two stroke 250 wont be as frugal as a similar fourstroke, but i think if you keep your lugage lightweight and to a minimum and dont go crazy with overgearing on the sprockets and leave it stock or just a shade taller geared you will be fine.
    Heavy loads of equipment tall gearing and a two stroke 250 with its powerband up in the rpms is not a good route to get good MPG, But lower gearing where you can keep the motor where its at its best for torque will be both smoother and give better MPG.
    The two stroke oil and transporting it is not a problem, the two strokes simplicity and reliability are a plus in any long distance motorcycle, and any time and load capacity taken up by mixing transporting a couple of litres of two stroke oil is low on priority.
    No valve adjustment oil filters engine oil changes needed on your ride less electrical equipment fuel pumps FI etc to go wrong on most two strokes make for less complication and easier on the road repairs generally.
    these are of course generalizations, but i think i would do it and look forward to it, and at the end of it you will be able to say you did it on a two stroke 250.
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  11. ihatemybike

    ihatemybike Been here awhile

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    I've been occasionally riding my KE100 as an adventure bike, strapping a tent and some gear to the rear fender. It's made the trip from Chicago to Deals Gap twice, but was transported back due to time constraints. It's done Chicago to Mississippi Palisades Illinois State Park and back. It was a tag along on a PNW trip, being ridden on the Oregon Trail and Pony Express Trail in the Rockies, unpaved roads in Grand Teton National Park, McKenzie Hwy in Willamette Nation Forest in Oregon, Columbia River Gorge and the beaches of Oregon.

    On trips it averages about 43 MPG and I haven't had an issue finding 2T oil at the gas stations along the way. With it's 1.75 gallon tank, I'm stopping to fill up about ever 40 miles, push 60-70 if I know the fuel availability for the area.
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  12. Branchbuster

    Branchbuster Long timer

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    Your next great leap will be the new port/ fuel injection KTMs which allegedly get in the 40 mpg ranges for fuel use. Might not be too long before you see the EXC WR gearbox version. They also have an autolube type system like Beta does (and many Japanese bikes of 70s). These bikes might make a comeback for those of us fed up with valves ,cams , shims and all that high wear crap/ weight going on up in that head.
    Get ready for their return to MX too. I hear their 250 will be a HP beast if they want it to be! We have not seen the last of the 2 strokes yet thanks to KTM and Yamaha.
    #12
  13. MATTY

    MATTY BORDER RAIDER

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    When you look at outboard motor two stroke technology these days it is interesting and i think the two stroke motorcycle has a real chance of regaining some of the lost popularity of the last few years.
    Well at least until all fossil fuel machines become just collectors items. :lol3
    Electric motion is on its way and is gaining some ground its a way to go yet but it is improving, sad fact is all these true electric cars bikes etc are being charged off fossil fuel power stations its all a bit confusing to me and i see it as just a game of passing the parcel at the moment anyway .
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  14. DiggerD

    DiggerD DougFir from SuperDuke Days

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    Back in the 60's I had a HD 165cc Super 10 2 smoker. The manual I got with the bike instructed you to "gas it" on long down hills to lube the cylinder. (My wording "gas it".)
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  15. porterrad

    porterrad Been here awhile

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    I read something similar in one of my manuals. This, combined with the low power for lights & my own stupidity nearly killed me once.

    I made the mistake of taking my WR390 down a very long & very steep mountain on a 70 mph Interstate one night. Before long, trucks were passing me as they tried to gain speed to get up the next incline. I started worrying that one wouldn't see my pitiful taillight & run me down, so I increased speed. Then I started worrying that the engine might seize, so I gassed it to oil the cylinder. The hill was so steep, it required almost no throttle to go 80 mph, but trucks were still passing, so I gassed it more. I was afraid to cut the throttle for fear of seizure, so I pulled in the clutch & revved the engine. Then I started worrying that I might seize the clutch throwout bearing, so I let the clutch out & gassed it some more. The WR was going over 100 mph when I reached the bottom of the mountain - easily the fastest I've ever gone on a dirt bike & faster than I ever want to go again.

    On long steep downhills, tall gearing might help put a little load on the engine & help oil the cylinder. Still, on
    an air cooled 2-stroke, I think high speed downhill seizure potential might be marginally increased because airflow cools the cylinder & shrinks it slightly.

    I ride a 4 stroke on the road now. I'm gonna hold off riding a 2- stroke on high speed mountain roads unless it has oil injection or some other lubrication system.
    #15
  16. MATTY

    MATTY BORDER RAIDER

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    In decades of riding 2 strokes i can honestly say i never encountered the downhill decent scenarios touched on on this thread and elsewhere.
    But thats just me, and i can see there could be a potential problem in the making regardless of if the bike is Autolube ....CCI or premix in lubrication.
    Now looking at just the Yamaha Autolube system for now, this system is not just how much the throttle is open it delivers more oil as the rpm rises even with throttle at slight openings but its only bleeding through as far as i know like this, and you get more with open throttle.
    Suzuki's CCI system is similar in this respect but it suplies oil to the bearings directly which the yamaha does not, i have never removed a CCI system for Premix on suzuki but i have done it on Yamahas regularly, the Autolube system is a great design, its practical and its convenient for just such scenarios of travel where you can fuel up relatively simply and just keep an eye on the tank every few fills you should be good.
    I like premix call me old fashioned if you like but with premix you know your getting oil its there automatically every sip of fuel it consumes no inherent system design shortfalls no mechanical failures no additional maintenance concerns of cables etc.
    I just like the basic old world simplicity and piece of mind that premix gives thats all.
    Auto lubes rarely fail and need relatively little barely any maintenance, but they can and do fail cables snap or lose nipples they can rust up gears and pumps themselves can give out , again rare but it can happen and it does happen.
    Premix can not fail as such it can be ill matched to task or incorrectly mixed either by rider error or misinformation, but its there doing its thing and working to 100% of its capability all the time, note i did not say 100% efficient as its only as good as the calculations of the mix for task in hand, but i dare stick my neck out and state.. Premix has less to go wrong and will guarantee some lubrication very close to what the engine needs all the time every time with no threat of not working through mechanical faults unlike autolubes which can not boast this .
    But as i said thats my own view on things re two stroke lubrication, and i will admit that when adjusted and working properly the Autolube CCI type systems work extremely well so i suppose its down to personal choice.
    #16
  17. juicy flawless

    juicy flawless Toxic Raccoon

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  18. JCool

    JCool Long timer

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    It's not a throwout bearing , but it can happen. Many bikes have a bushing rather than an actual rolling bearing.
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  19. Strong Bad

    Strong Bad Former World's Foremost Authority Supporter

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    When racing Baja back in the 70's on 2 strokes while tucked in screaming across dry lakes or uber fast roads, we would reach down every once and a while hit the "tickler" on the old Bing or Amal carbs, just until it blurbels. Would do the similar thing while racing Hodakas in the desert, hit the choke lever for jut a second to fatten it up. The main thing is to have your jetting set properly and not too lean and 99.999% of the time you should be good to go.
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  20. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    Good discussion. I've ridden my Beemer Airhead everywhere, forever. Got my other dream bike, a 125cc Hodaka Wombat and it's taken some getting used to the old-school premix 2-stroke engine. Every bit of info helps.
    #20