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· Registered
9 Posts
Discussion Starter · #1 ·
Ok here goes, I recently tore my 2005 TW down to paint and put on new tires. It sat in the garage for about a month and I started it once or twice a week. When I put it all back together it wouldn't start after starting it inside two days prior. Havin good spark and starting it with starting fluid only I decided to open up the carb and take a look around. I only went as far as the float bowl and cleaned the jets and reassembled. After doing this probably four times I could only get it to run for short periods of time very crappily. After that I installed a 130 main jet and a uni pod filter and got it running what seemed pretty well at first glance but after putting a couple miles on it it was running rich enough to sputter and backfire. I tried changing up the air/fuel mixture with no great changes. Rode it about ten miles and fouled out the spark plug, put my spare in and limped home. At this point I cleaned the spark plug and got it back to semi crappy running while puffing small amounts of black smoke. Now it won't start at all even with a spotless spark plug.

Can someone PLEASEEEEEEE give me some insight before I take to Yamaha for them to "figure it out" at $90 an hour.

· Registered
22 BMW G310GS, 2018 Van Van,
969 Posts
Go back to the configuration that worked before. These units (like most IMHO) work best in stock form. Stock airbox, filter, exhaust and main jet.

Make sure your float needle isn't sticking and your idle circuit clear, base setting 2.5 turns out. Easy to remove the carb to "do it proper" Great tutorials on this site.

When it runs fine again then add your "high performance" parts.

Draw your own conclusions about the "high performance parts".

Make sure you still have spark too. As the master used to say "If your intutition say's carburator best check the igniton, you are technician not a psychic"

Base suspicion would be crud in the idle circuit, masked when you added the large main jet so it runs too rich everywhere except idle circuit as it was running lean due to a plug.

Good Luck

· Registered
1,931 Posts
... I recently tore my 2005 TW down to paint ....

...sat in the garage for about a month... went as far as the float bowl and cleaned the jets and reassembled.

... After that I installed a 130 main jet and a uni pod filter
You didn't mention if the carb has ever had a thorough cleaning.

Cleaning the jets is only a start. There are several tiny passageways that must be clean for the bike to operate properly.

The unipod filter and unplugged exhaust make all standard settings irrelevant. (You should only make one change at a time.)

The unipod should allow much more air into the carb than the standard air box and filter, and it should run lean.

But from your description, it's running rich.


Make sure the carb is really clean... jets and passageways... you will need to remove the carb to do this.

(Importmech posted a good description of how to do this if you don't have an ultrasonic cleaner.)

Reinstall the stock 126 main jet.

Make sure all carb parts are assembled correctly.

Make sure you have fresh fuel.

Priority, in my opinion, (others may disagree) is to get the engine to idle properly.

If it doesn't idle right, the the rest of the tuning will be off.

The idle jet and its associated passageways must be clean.

Then start adjusting the idle screw. Most start with 2 to 2 1/2 turns out.

With the unipod, I would start with with 1 turn.

(Lizrdbrth has a great description of the procedure... can't find it right now.)

Also try full choke, 1/2 choke, and no choke to see if that makes a difference.

The choke circuit (enricher) bypasses the pilot jet circuit and dumps fuel directly into the manifold.

This can be a tedious process, but needs to be done before anything else can be addressed.

* I am currently on the road, and have limited internet access. It may be a while before I check in again.

Others feel free to make suggestions.


· Registered
1,931 Posts
where is the pictures of the bike,spark plug and tell us the sea level your at. I don't think 130 is too much at all for a pod filter. I got one.
Rising Sun, I agree about the 130.

But from his description, the engine is running rich ... it shouldn't be.

I think there is something else wrong.

What is the pilot screw setting on your carb with the pod filter?


· Registered
433 Posts
I have a stock pilot screw. Nate do not ride anywhere. You can tune it just turning the throttle. turn the throttle a quarter engages the pilot jet. If you hold it open it engages your main jet. Closing the piolt screw and opening it quarter turns until its right. It takes time. Popping backfire noises dictate where its going wrong as well. Deep backfire noises mean too much fuel. High pitch backfires mean its too lean.
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