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2004 TW200
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Discussion Starter · #1 ·
I’m a new TW owner. My other bikes are orange Austrian things. I don’t expect the TW to be anything like them in terms of performance, but I think the one I bought is pretty weak. It’s the only TW I’ve ever been on so I have nothing to compare it to.

It’s a 2004 with 15k miles, no smoke, not using oil. I don’t know the history. The PO hadn’t owned it very long, but he went all out on upgrades and it appears to be in good shape. My concern is that compared to what I hear people saying mine sounds weaker than average. For example, totally pinned on a flat road it can barely maintain 55mph. Uphill or head wind and not even 50mph. It’s geared +1 up front and -1 on the rear sprocket. I’m 6’4” 190 pounds, so bigger than average, but not a huge load. When I first got it I had to rev it pretty high just to keep it from stalling when taking off. I adjusted the valves and did a dynojet kit and that helped a ton on the bottom to mid. The valves were in spec when I checked them, but I went ahead and adjusted them to the middle of the spec. I hear people saying they ride their TW as a dual sport bike. I’d be a road hazard on anything with a speed limit of 50+mph or any kind of hills.

I mostly ride it off-road for exploring in the desert and woods and it does ok as long as I keep the revs up. I thought I’d be riding it from the house to get to the woods, but it’s not up to that. I did a 100 mile ride mostly on flat dirt road with some really gnarly jeep roads thrown it. I was pinned on the flat stuff all day just hoping for 50mph. I was surprised that it still got over 70mpg on that tank though.

Any suggestions or opinions welcome. Thanks.
Tire Wheel Vehicle Automotive tire Motor vehicle
 

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Could be that by dyno-jetting the bottom and the mid, you did so at the expense of the top end

Anyhow - welcome to the board, I'm sure others will add their thoughts as to what ails you ......
 

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Welcome home, Chris. Someone geared it up thinking they'd get better fuel mileage or a higher top speed. They were wrong.

Get back to factory sprockets and it'll be much better off-road and you'll go 60 or 65mph on the pavement.

Unless it is a new x ring or o ring chain, now is the time to to get a good chain also. Otherwise, this thing will probably do what you expect of it. You are definitely not too much weight for it. In fact I'd say you are a bit on the light side. I recommend beer and run steak.

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The bike should hit 60 mph at least relatively easy. Getting to 70 mph you may have to head down hill or behind another vehicle. It sounds like you have an issue of some sort. Check your tank vent and make sure your main jet is sized properly. You may want to check for intake leaks also which would lean the bike down.
 

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If yours is lacking, it's not much. Both of mine top out about the same. The only thing you describe that seems off is having to rev it to get rolling, but your taller gearing may explain that. As Loghousenut touched on, gearing up doesn't really gain speed or mileage unless you're built like a jockey. TWs are much closer to a Doodlebug than anything Austrian.
 

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Loghouse nailed it.
+1 on counter sprocket would be enough for your symptoms.
-1 on rear makes it worse.
 

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2004 TW200
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Discussion Starter · #8 ·
Thanks. I’ve thought of dropping the gearing back to stock anyway. The PO spent a lot of time and money getting it all tricked out but probably only put 300 miles on the bike. The chain and sprockets are new and it came with new stock sprockets too. It seems to be a bit of a PITA to change the front sprocket. Having to pull the side cover etc. I’ll report back once I get around to it.
 

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I found 14/55 to be a good all-around ratio for the type of riding I do, whichisprobably90% off-road. 50-55mph is about where it comfortably tops out. It'll go a little faster but I don't like running it that hard. It's a noticeable improvement over stock on the trails. Goes anywhere I need it to.
 

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Stock gearing on a XT250 is 15-48.
For my current type of riding, I have considered a 16 tooth counter sprocket or a 45 tooth rear.
Either would be 1:3 gearing.
I think it would be good, on the street, in the first 3 gears, but maybe not for 4th and a concern for 5th.
I am in third completing a left turn.
The problem with 5th is the ~20 MPH difference in top speed downhill versus uphill and/or downwind versus upwind.
At ~475 miles in the past two weeks, run-in feels complete, but I am not yet holding WOT more than a couple seconds.
At less than full throttle, going up highway 95 with a headwind, typical speed is 60 MPH, whereas it could be 80 (briefly) coming back.
So, at this point, will retain stock gearing.
 

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It’s not bad off-road as long as I keep the revs up. I’ve done some pretty gnarly steep rocky jeep roads with it already.
Might try putting a new spark plug in and taking a plug reading to check your fueling.
I run a 15 X 44 sprocket combo in my '87, I am 6'-2, 175#.
Works well in most situations (NOT tight technical stuff)
 

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BTW, I do not recall for the TW, but the counter sprocket nut for the XT250 is 30mm.
I rode around yesterday looking for a 6 point 30 mm 1/2" drive socket and only found 12 point.
12 point is appropriate for a box wrench, but why for a socket, unless a 12 point bolt head?

Yes, I can order from Amazon ($10), but not available at:
AutoZone
O'Reillys
Tractor Supply
Home Depot
Lowes
Harbor Freight

Now, back to the topic
Comments re new stock 2017 TW200:

 

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Your TW's engine output sounds normal.
The 15 tooth front sprocket's ~7.5% reduction of RPMs at speed has your TW running up against the wall of exponentially increasing air resistance and rolling friction when trying to ride above 50 mph. The additional tooth in rear adds another 2% of trouble and lazy acceleration.
Right when you want max power your engine is unfortunately running at rpm levels beyond it's peak HP and torque where dyne curves tend to fall off.
14x50 or 14x55 would be my recommendation for a more rewarding riding experience, just forget about freeway speeds with a 198cc low tech slow turning old school thumper.
With the stock motor I would typically still get a 50 mph fast cruise with 13x55 turning a slightly larger diameter ATV tire, not much different that the stock top speed but with a lot more authority accelerating on its way up to top speeds.
I always run one of my bikes with the 13x55 sprockets selected even though it has custom dual front and rear sprockets to really reduce the final drive ratio with 4 different possible combinations for Bonnieville speed runs.

I admittedly am an off-roader and very willing to spend a little extra time getting close to my destinations if it means I can actually arrive at my destinations without the struggles and uncertainties that tall gearing brings when things get technical.

If you really want more out of the TW configuration consider an engine swap. My other TW has a bored out TTR 6-speed engine with same 13x55 sprockets making it much more tractable with more power available over a wider speed range. Wider ratios of the TTR 6-speed makes first gear likely lower than most would prefer but I occasionally need the added low speed grunt to clear obstacles. In this case I might be happier going 10% back closer to stock sprockets.
 

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I think you have a problem with the motor in some way and that this is not normal. I'll quote you here why I think that:
When I first got it I had to rev it pretty high just to keep it from stalling when taking off.
You then jetted and adjusted valves and said that helped with low end.
But then you said this:
I mostly ride it off-road for exploring in the desert and woods and it does ok as long as I keep the revs up.
That contradicts what you said previously that the jetting and valve adjust:
I adjusted the valves and did a dynojet kit and that helped a ton on the bottom to mid
Your gearing is going to lean towards less low end torque and need for higher rev launches, but I doubt it's enough that you have to rev the engine much to do so. Your gearing leans toward higher top end speed, which you are not getting.

So let's first confirm your sprocket gearing. You said:
It’s geared +1 up front and -1 on the rear sprocket.
Let's confirm what stock is first: 14/50 front/rear. So +1 up front is 15 teeth and -1 in rear is 49 teeth. Is that what you have?
Now let's go to the website Gear Commander and put in the TW200 years 87-13.
Leave the stock ratio as-is and modify the current ratio to yours at 15 and 49.
Rectangle Font Parallel Screenshot Number


Now scroll down to the next chart and notice that the stock gearing at 55mph is turning the motor at 7200 rpm.
Rectangle Font Parallel Pattern Screenshot


Now click on the "Current" tab and enter 6500 in the minimum rpm box. Notice the current gearing you have at 55mph is turning the motor at 6500 rpm. (Note: the ZERO rpm default has the top speed somewhere between 6300 and 7200 rpm for the speed we want of 55mph, so I adjusted the minimum rpm box to discover exactly how many rpms it takes to go 55 mph with your current gear ratio)

Rectangle Font Parallel Pattern Screenshot


As these charts show, you are turning 6500 rpm at 55mph.
So from what I can see and read from your post, you have both poor performance in the lowest rpm range and the mid to upper rpm range. Just for clarification, a TW200 should be able to run reliabliy at 2,800rpm all day long grunting through rough terrain and at 3,000 to 4,000 climb anything short of near-vertical without stalling. These things really are goats when running right. Also for clarification, they should easily reach 8,000 rpm on flat ground. Both of these clarifications will not be affected by gearing, since I'm talking rpm, not mph. Most times you want to ride off road, you gear down so you can ride at a pace you can manage the terrain. Most times you want to ride on-road, you gear up so you can ride at prevailing speed limits without screaming the motor rpm.
In YOUR case, you have neither low end rpm grunt power nor upper rpm speed.

With that established, let's discuss why your bike is so weak at lower rpms to the point you can't even launch or ride off road without revving up the engine and why your top end speed can't get you to over 55 on the flats.

Obviously the top speed on the road is the first concern to keep from getting run over or being a hazard. At 55mph, your gearing has your motor turning 6500 rpm and that's topping it out. That is a problem. A BIG problem. The causes are many, but you alluded to one that I have been recently made aware of by a memeber here that goes by oldworld124, AKA John. John and I have been discussing the TW's performance as it relates to aging engine components and something he made me aware of is how valve springs get weak over time and what the result in performance it causes. In a nut shell, the springs have a set of specs that John has measured on a couple top ends and he's discovered that they age out over time and get to the point that they no longer are at their optimal tension. This results in what is called "valve float". Valve float happens when the valve train is moving so fast, the spring can not keep up with the rpm and the valves do not fully close under the current spring tension, resulting in a couple problems; one is a loss of performance, much like you are experiencing. Another is the floating valve that isn't seating all the way before the cam lobe goes to open it again can hit the piston as it comes back up to TDC. Since the valve is floating, this should not result in catastrophic engine failure, but can put a dent in the piston crown. I've got such marks on my piston and suspect I have weak valve springs. I also notice I cannot ride flat ground above 8000 rpm even though the motor will turn 9000 rpm in neutral and revving the throttle. I have no issue with low speed performance though, so let's just hold off on that for now.
What alluded me to the possibility that your valve springs are weak is the age and milage on your bike. At 15,000 miles and being an 18 year old motor, it's quite likely your valve springs are beyond spec.

There may be other reasons for the poor performance, things like the CDI is on it's way out, a clogged air filter, low engine compression, etc. But I'll assume you've checked the air filter and the air feed from under the seat to the filter is not blocked in any way. Mice tend to use this area to store and nest, and while the filter is clean, the intake can be obstructed. Engine compression should also be tested. A compression gauge off Amazon is cheap, under $25 and a great investment as a means of testing motor performance.
I will also assume, but mention anyway, that you have changed out the spark plug for a fresh one. It's not uncommon for them to develop cracks that can only show up at higher rpm and compression but work fine at other speeds. Some other things that can affect top speed performance are:
tire pressure
chain condition
engine oil vecosity
engine timing (set by the rotor and wood drift key, the key can break and the rotor move out of position.)
valve timing (set by the cam gear through the cam chain and can either jump a tooth if the cam chain tensioner is not set properly or the chain has stretched excessively)
Carb jetting, especially the pilot jet, tends to easily get blocked or partly blocked. If your bike runs better at half choke at higher rpm, then it's a possibility. Try setting the choke at half way while at speed and see if the top speed increases. If a throttle chop at top rpm results in a popping back-fire, it's definitely too lean.

I would start with the easiest of these possibilities and work my way up. But if I were a betting man, I'd bet that either the cam chain has jumped a tooth, stretched or isn't tensioned correctly OR that the valve springs are weak and need replacing.

Keep us informed what you find as you continue troubleshooting your problem.

P.S. Some folks here might loan you a spare CDI if you get to that point. It's a way to confirm the problem by isolating without having to spend a few hundred bucks.

** EDIT **
I want to add a couple other things:
fuel flow: make sure you have full fuel flow. A clogged filter in the tank could restrict fuel flow and prevent top speed. There's also a filter screen inside the carb at the float needle. To test, open the carb bowl drain screw and the fuel petcock on the tank. You should see a steady, robust flow of fuel coming out that hose. Be careful seating the drain screw and only close it lightly. Many have damaged the screw or bowl by trying to over tighten.

Also be sure you have good quality fuel. Flush the tank by removing it and turning it over. Allow to air dry and inspect it with a flashlight. It should be spotless.

While you are at it, add an in-line fuel filter.
 

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You've only got 12-14hp between your legs. There's only so much that can be done with leverage. Even with my XT swapped bike, my upright body catching wind costs 4-5mph vs tucking down on the tank. I don't think there's likely anything "wrong" with your TW. It may just not have optimal gearing. There are guys who claim to do 70+ on theirs. That may be true but I've never been able to and none of the guys I've ridden with have done it while I'm around. Remember, it's a TrailWay200 not a FreeWay200.
 

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Without re-reading everything above- I do not recall your elevation where you live being stated. That is also a very big factor in the engine output of such a low displacement, low HP engine.
As for jetting, if you are too large on the main jet in relation to elevation, you may be over-jetted and slowing yourself down.

As stated they are very low power and there just is not much oomph there, to be honest. Maybe a different bike is in order for you? There are many great choices if you want more oomph, suspension, speed, handling etc...
 

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Without seeing and riding the bike myself, I would say it's probably at least mostly normal -- perhaps with one or more minor flaws contributing to slight power reduction. As others have noted, you're starting out with only 16 CRANK horsepower from that motor -- and that's assuming the bike was properly broken in (highly unlikely, as most people don't bother) and isn't suffering from any power-sapping maintenance-related or modification-related flaws (which, again, it may well be). With the tall gearing you're running, those saddle bags (weight and aero drag), and a big guy like you with full riding gear (also weight and aero drag...), a stock-power TW will definitely struggle, especially if you're riding into a moderate to strong headwind. Compared to any "normal" motorcycle, aerodynamics plays a much bigger role (relative to available power) on small, underpowered bikes like the TW.

Some quick things to check/consider (which may or may not have already been mentioned...I'm trying to make this quick):

-gearing: maybe try stock or 14/55
-tire pressure: if it's low, this can create extra rolling drag
-air filter: if it's dirty and/or grossly oversaturated with way too much oil, this can have a significant effect on power
-drive chain: if it's too tight, this can adversely affect power delivery
-spark plugs (including gap! -- might not have been checked/set during installation?), valves, carb innards and settings, exhaust system (aftermarket?): any of this sort of thing (as you know) can certainly have a negative impact on overall performance; consider taking that all back to stock
-air intake leaks: if your TW is quite old, there could be some cracking/ dry rot on intake boots; if it's newer, something may have been installed improperly / clamps not tightened down, etc.

Of course, there are other possibilities, but again, these are just a few quick thoughts and things that you might look into.
 

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And there you have it – it’s your jetting, your gear ratio, you’re too tall, your air box is full of mice, your CDI is failing, your valve springs are shot, and you have bad compression along with clogged fuel filters and bad gas, combined with a duff spark plug

While we’re on the subject – have you checked your tire pressures ? - (I see kj beat me to it), and added a tight chain and air intake leaks to the mix

Meanwhile, there’s someone on here who’s selling a TW that does 80mph

Confusing ‘aint it

How can such a simple thumper be fraught with so many potential problems …… :cool:
 
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