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Discussion Starter #1
I just purchased a used 2014 TW.

It starts up fine with a choke but I have to ride around for at least 15 minutes with the choke before it warms up enough where I can turn the choke off. Otherwise the engine dies when I open the throttle. Is this a normal warm up period?

So far I’ve turned the jet 2 1/2 turns as recommended and the popping on deceleration has resolved. I’m about to add a couple washers on the needle.

I’m at 6500’ elevation and the bike is stock California model.
 

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Before you do washers use some Seafoam in the tank or remove, clean and inspect the pilot jet. Some just replace it. It has a tiny hole that plugs easily especially with ethanol gas. I have used a strand of copper wire from stranded electrical cable plus carb cleaner to clean the pilot hole carefully. Another option is to go up one size to a #34 pilot jet. My bikes have a modified exhaust and so needed to be rejettied. Not sure you need to go bigger pilot at your altitude. If you just try Seafoam it will take a few days to help clear the jet.

Edit buy Yamaha jets.

I just purchased a used 2014 TW.

It starts up fine with a choke but I have to ride around for at least 15 minutes with the choke before it warms up enough where I can turn the choke off. Otherwise the engine dies when I open the throttle. Is this a normal warm up period?

So far I’ve turned the jet 2 1/2 turns as recommended and the popping on deceleration has resolved. I’m about to add a couple washers on the needle.

I’m at 6500’ elevation and the bike is stock California model.
 

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Is this a normal warm up period?

So far I’ve turned the jet 2 1/2 turns as recommended and the popping on deceleration has resolved. I’m about to add a couple washers on the needle.

I’m at 6500’ elevation and the bike is stock California model.
No, definitely NOT normal! My 2018 (exactly the same as my 2010) warms up in 10 seconds on full choke and another 30 seconds on half choke at below 40 degrees. Above that it only needs 30 seconds on half choke and above 70 degrees no choke at all.

At 5,700 feet, nearly the same altitude as you, I use 2 to 2 & 1/4 turns and NO washers. Use Seafoam before making any changes other than turning the pilot needle in slightly. Your problem is almost certainly the result of Ethanol fuel left in the tank too long.
 

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Discussion Starter #4
Thanks for the feedback. I opened up the carb and it was sparkly clean inside. I added the 2 washers and left the pilot jet at 2.5 turns. It started right up with the choke and after a minute or so of warm up it ran like a top.
 

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Good that it is running better. I would still follow the Seafoam advice since your adjustments seem very rich for your elevation. Certainly they would make my bike run uncomfortably rich at comparable elevations. With stock jetting and a mixture screw setting of 2 revolutions out from seated my 2003 & 2006 California models start right up without use of the enrichening circuit at elevations above 5,000 ft and temperatures above 40 degrees F.
Of corse every bike is a bit different but I suspect a little degraded fuel scum is responsible for the slow warm-up and lean symptoms. A little icleaner like Seafoam, Lucas Deep Cleaner, or others can often work big improvements.
 

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As Fred said glad it is running better. When I have let my bikes sit for as little as 4-8 weeks a hard spidery web formation gets in the pilot jet the rest of the carb looks sparkly clean. Sometimes the Seafoam gets it out and sometimes I need to clean it. The solution is to ride them more. Lol.
 
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Discussion Starter #8
I’ve been reading the tech write ups and trying to learn about carbs. I understand the main jet helps the high end, needle the mid range and the pilot jet low end. What is the difference between the pilot jet screw and the pilot jet? #16 and #15 on the diagram below. I’m assuming the jet screw is what adjust the lean? What does the other pilot jet do? Thanks.

https://www.yamahasportsplaza.com/oemparts/a/yam/52869fd1f8700230dc2a77a3/carburetor
 

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I’ve been reading the tech write ups and trying to learn about carbs. I understand the main jet helps the high end, needle the mid range and the pilot jet low end. What is the difference between the pilot jet screw and the pilot jet? #16 and #15 on the diagram below. I’m assuming the jet screw is what adjust the lean? What does the other pilot jet do? Thanks.

https://www.yamahasportsplaza.com/oemparts/a/yam/52869fd1f8700230dc2a77a3/carburetor
This below can put it into better words than I ever could.





  1. Pilot or idle jet system.

    The idle jet controls the idle and on up to quarter throttle, give or take a bit. On some carbs, like Mikuni there is an air jet too. In conjunction with the idle jet there is an idle jet air screw. This screw leans or richens the fuel mixture for a smooth idle and on up to one quarter throttle. From the idle jet, there are little passages cast into the carb that lead to holes just in front of the throttle valve or plate. There can be just one holeor there can be several, depending on the carb design. They effect the mixture as long as the vacuum, in the venturi, is over them. As the throttle opens further, the vacuum moves to the needle jet and jet needle.
Here is the source URL's:


Carburetor Theory and Tuning
Dan's Motorcycle Carburator theory and Tuning



The Idle Circuit
Dan's Motorcycle "Idle Circuit"
 

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So Kermit I didn’t want to comment but I think you cured your symptom and not your idle problem by raising the needle. The needle affects the whole throttle range from idle to full. It is slightly tapered and by raising it you enriched the idle circuit which seems to have helped. But your pilotjet could still have a restriction in it.

Raising the needle added a lot of pop to my bikes midrange because of the DG pipes. Did you notice any increase in acceleration in your midrange throttle after adding the shims?
 

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Discussion Starter #11
I haven't ignored your advice. I'm waiting to use up the old gas and put a fresh tank of high octane with Seafoam. The bike is actually running great. *I think*. I just sold a 1200cc Super Tenere so obviously the TW feels like a putt-putt but it starts right up and feels smooth for the most part. Its holding a nice idle but the max speed is only about 55-60mph. Initially the popping on deceleration improved with the needle shims and turning out the pilot screw but its back this morning. I'm at 6500' and its cold out so that may affect things. One of the reasons I bought this low-tech bike is so I can learn how to work on bikes (unlike the S10 which was pretty intimidating). I just like tinkering with things and I'm the kind of guy who fixes things until it breaks.

Is that pilot jet (#15) adjustable - as in it can be screwed in and out or just replaced for a different size? What does it do compared to the pilot screw (#16)?

I've read a lean setting can destroy an engine. I'm assuming its better to err on the side of running rich?
 

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Good idea to put in fresh gas and seafoam. I would skip the high octane - our Dubs don't need it - high octane just retards how quickly fuel burns, thats needed in high compression and forced air applications - not our basic TWs. Actually running high octane in a low compression motor will lead to carbon build up over time.

My TW was cold blooded when I first bought it - it was a year old with 25 miles. I siphoned out the old fuel put in fresh regular and a double dose of seafoam and by the end of running that tank it started w/o choke needed.
 
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