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Cleaning Used Throttle Body

m_stock10506

Active member
I purchased a pair of used throttle bodies.
My plan is to clean them up, send the injectors out for professional cleaning and eventually swap them onto my R1100RT (currently 100k miles). So, I don't have a parts washer or ultrasonic cleaner. I've got an aluminum roasting pan, simple green and any other bottle of cleaner chemical available at the local auto parts places. What's my best choice to get these cleaned up. They are fairly grungy both inside and outside.


Used Throttle Bodies.jpg
 
I purchased a pair of used throttle bodies.
My plan is to clean them up, send the injectors out for professional cleaning and eventually swap them onto my R1100RT (currently 100k miles). So, I don't have a parts washer or ultrasonic cleaner. I've got an aluminum roasting pan, simple green and any other bottle of cleaner chemical available at the local auto parts places. What's my best choice to get these cleaned up. They are fairly grungy both inside and outside.


View attachment 37193

Just make sure you remove the TPS before using any strong solvents on the TB's.
 
soak them in vinegar with lemon juice
That's a new one on me. Does it by chance cut corrosion etc too? Where do you use it? What sort of mixture? How long to soak?

I was going to suggest carb cleaner & cotton swabs, here. I know carb cleaner will dissolve a toothbrush handle. DAMHIK.....:)
 
Several different methods. My favorite is 1 part vinegar/2 parts water and soak for 24-48 hours.
You can also heat it on the stove and cook the parts for 1-2 hours.
I'd try on a small piece first to test for discoloration.

It's jsut a mild acid.....

Ken
 
I've heard of folks using a pine sol solution. Go over to adv riders forum and read up on it.

Personally, I have not tried it... yet
 
I recently learned about a 50/50 mix of Dawn dish wash liquid and white vinegar as a degreaser. The vinegar needs heating to coffee temperature prior to mixing so it combines better with the soap. Biodegradable is a plus.
Works very well. Spray on, scrub with stiff brush and rinse with water.
Cheap, too.
 
I've heard of folks using a pine sol solution. Go over to adv riders forum and read up on it.
Personally, I have not tried it... yet

Yep, going to try the Pine-Sol soak. It will take a few days before I can report back but I will provide results.
 
Clean Throttle Bodies

Done.
I soaked the throttle bodies in a mixture of Pine-Sol and water in a 1:1 ratio. The water was hot when I started this. Soaked the right side TB for about six hours. I used a soft toothbrush on a few tough spots but that might not be necessary. Then I removed it and rinsed, first with warm sudsy water, then just hot water. With the hot water I was able to remove the rubber manifold between the TB and the cylinder which was stuck on before.

Then I placed the left side TB into the Pine-Sol solution after adding a bit more of hot 1:1 mix. The TPS was removed before the left TB went into the bucket. Soaked it for six hours too. The mix was pretty dirty after the first TB and this may have reduced the effectiveness as the left TB did not clean up quite as well as the right TB. The insides cleaned real well on both, just the outside of the left TB was not as clean.

Photo of the Right Throttle Body, before and after.
Throttle Body Right 1.jpg
 
Carb Cleaner

Just went thru this exercise on mine this morning using a commercial carb cleaner. Used a tooth brush and fine steel wool and the results weren't near as impressive as these. Since they are still off the bike, I'm going to soak them and see how they do. I'm curious, the right throttle body has substantially more black buildup than the left. Mine looked just like that also. I was concerned that there might be a problem in the balance. Any thoughts?
 
Actually, I only posted one photo of the left side throttle body - the photo of the exterior. The interior photos, showing the left throttle plate from front and rear views, those weren't posted because they were pretty much the same before and after conditions as the right TB. On both left and right TBs, the throttle plate is much more carbonized on the front side of the throttle plate, the side that faces the cylinder. Not really surprising since that's where the gas gets ignited. The side facing the rear, towards the air box has much less buildup.
 
You guys cleaning throttle bodies - Be SURE to visually inspect the all porting etc for the big brass screws (BBS) so that they are whistle clean before reassembly. I used a Q tip with carb cleaner to clean the BBS area, and a soft wire to verify the porting was clean. It is nice to have the inside and outside clean per above, but the BBS area is critical for final setup, balancing, and freedom from surging.

My hunch is that it is the different tradeoffs between the throttle stops and the BBS settings that causes surging, since the net airflow to the engine is optimized via the TPS on only one side of the engine. The other side has to be close to the TPS-monitored side for the mixture to be within an ignitable range on that other cylinder.

Throttle shaft leakage could be an issue too.
 
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