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Discussion Starter · #1 ·
I have been fiddling with this stupid carburetor for ages. Right now I have the #114 main jet and stock main jet holder, one small shim on the needle and the air/fuel mixture screw is backed out 2 full turns. That is the best I have been able to get it but it's still not great. I can do about 50MPH in either 4th or 5th gear, I'm not able to go any faster in 5th than in 4th. It doesn't sputter or cough like it's running rich. When I'm at WOT in 4th or 5th on a flat road and doing about 50, if I pull the choke all the way out, nothing changes at all. I can't tell if it's running lean or rich. I'm running ethanol free in it.

Any tips on what adjustments I should try next? I have a few different main jets available, a Chinese aftermarket main jet holder that doesn't have as many holes in it as the stock one (and I could never get it to run well at all with that one, that's why I went back to stock), and of course I can play around with shims and washers. I'm using the stock needle as well.

Also, I have kept the stock front sprocket, but switched the rear to a 45 tooth. My goal for this bike is to be about 50/50 on/off road and be capable of going on the highway, I have heard of people getting their TWs to go 70+ MPH and I would like to achieve that if I can do it without totally compromising my off road ability.

Any advice is appreciated.
 

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1987 TW 200
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54 Posts
no need to shim the needle. back to the factory setting #114 main jet #40 pilot jet air/fuel mixture screw is backed to the one & half a turns.
Unfortunately, on the roads of Sri Lanka, it is not possible to go continuously for more than one or two minutes at a speed of almost close to 70 miles per hour...( I'm running 14 tooth front sprocket & 45 tooth rear)
I can get close to 95 km/h in fourth gear
ride safe
 

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Discussion Starter · #3 ·
no need to shim the needle. back to the factory setting #114 main jet #40 pilot jet air/fuel mixture screw is backed to the one & half a turns.
Unfortunately, on the roads of Sri Lanka, it is not possible to go continuously for more than one or two minutes at a speed of almost close to 70 miles per hour...( I'm running 14 tooth front sprocket & 45 tooth rear)
I can get close to 95 km/h in fourth gear
ride safe
And I thought the roads out here in Maine were bad! I'm a little jealous, I bet you get some fun riding out there with the jungle and the mountains. And the food is really good if the Sri Lankan restaurant near me is anything to go by.

Remember that carb tuning settings vary by altitude and atmosphere and stuff, so the settings that work for you in Sri Lanka might not work for me in Maine. I tried those exact settings you suggested and got pretty bad results, not as good as the 2 turns out on the screw and shimming the needle with a small washer.

I am starting to think it's just lacking in horsepower and this is as good as I'm going to get until I put new rings and gaskets in it.
 

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2001 TW200, '89 carb
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And I thought the roads out here in Maine were bad! I'm a little jealous, I bet you get some fun riding out there with the jungle and the mountains. And the food is really good if the Sri Lankan restaurant near me is anything to go by.

Remember that carb tuning settings vary by altitude and atmosphere and stuff, so the settings that work for you in Sri Lanka might not work for me in Maine. I tried those exact settings you suggested and got pretty bad results, not as good as the 2 turns out on the screw and shimming the needle with a small washer.

I am starting to think it's just lacking in horsepower and this is as good as I'm going to get until I put new rings and gaskets in it.
It is most definitely lacking in horsepower, but that's standard for a Tdub. I'm in Kansas City so slightly higher elev than you and my main jet is a 110, pilot 40, no shim, two and a smidge turns. I would suggest making sure that you don't have any leaks at the carb/engine and air box/carb interfaces. If you've got an 87 with original parts the air box and engine boots have got to be as hard as rocks and likely not sealing well or cracked. If so, you'll find it hard to fix with jetting alone.
 

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1987 TW200
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You might have an electrical issue instead of a jetting one. I bought an '87 TW last year and I went through the carb 3 times before I figured out I had a CDI issue. The bike ran reliably but wouldn't perform at high RPM. I found the CDI wasn't advancing the ignition timing. Once I replaced with a Waterloo upgraded CDI the bike ran MUCH better and I put all my jetting back to stock.
 

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You might have an electrical issue instead of a jetting one. I bought an '87 TW last year and I went through the carb 3 times before I figured out I had a CDI issue. The bike ran reliably but wouldn't perform at high RPM. I found the CDI wasn't advancing the ignition timing. Once I replaced with a Waterloo upgraded CDI the bike ran MUCH better and I put all my jetting back to stock.
My 87 runs best at 2700 feet elevation with a 110 main jet, 3 needle shims, 42 pilot jet and 2-1/4 turns out on the idle mixture screw, FWIW!
 

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Discussion Starter · #8 ·
You might have an electrical issue instead of a jetting one. I bought an '87 TW last year and I went through the carb 3 times before I figured out I had a CDI issue. The bike ran reliably but wouldn't perform at high RPM. I found the CDI wasn't advancing the ignition timing. Once I replaced with a Waterloo upgraded CDI the bike ran MUCH better and I put all my jetting back to stock.
That is the advice I was really hoping not to hear. I will try that as a last resort, if it's still feeling sluggish after I finish the ring job. Rings and gaskets just showed up this week, I was going to start working on it right away but, yet another piece of evidence that the universe is determined to keep me from riding, my water heater shit the bed the next day and now I have to deal with that instead.

Was this the one you purchased? 87 to 97 TW200 NEW CDI BOX 10 year wtty 2JX-M0 2YG-M0 2YG-85540-M0-0 | eBay
 

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1987 TW200
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Yes, but I think I bought it straight from their website instead of ebay. You can troubleshoot the CDI (and stator and stuff) by just checking some resistances on an ohm meter. I was able to identify my problem that way, and didn't have to tear into any mechanical stuff to do it. I forget the values and procedure but you can find it all on this site. If this is your issue no amount of mechanical work will make up for it, so do the checks as soon as reasonable.
 

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Are you using a brand new #114 jet? If its the original jet get a new one no matter how good it looks. I struggled to solve my TW's problem of poor performance which was instantly cured with a new #114 jet. Later I changed to a #112.

I also have an '87 and ride from sea level to about 3500'. Main jet now is #112, pilot #40, no shims, and the idle mixture screw is out about 2 to 2 1/2 turns. I replaced my CDI because there was an erratic miss. I sent my old CDI to Baurer, I think that is his name, and he fixed it so now I have a backup.

I also bought a CDI for some guys in the Czech Republic. The CDI had an adjustable advance curve. I played with it for a very little while and now it sits on the shelf.
 
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