Throttle Body Synchronization

[FJReady]

It had been 25K miles since last spark plug change (I know, shame on me) and TBS adjustment. It makes sense to me to do them together since to take advantage of being under the tank.

I was surprised how much difference there was between the cylinders.

Before adjustment:

I took the photos with rpm set at 2500.

After adjustment:

Yes the engine is running in this photo. Only took adjusting cylinders 2 and 4 to achieve this.

I didn't take it out for a ride to see if I can't detect and performance (smoothness) improvement.

But I must say I was surprised how out of sync it was before the adjustment. Previous times the spread was noticeably tighter.

 

[yamafitter]

I thought TBS is done at idle and checked at 4000 rpm. Am I wrong?

I need to check / clean the K&N air filter and change the plugs before I do mine.

 

[Bungie]

I picked up a used (never used) Morgan Carbtune from a local guy selling his FJR late last fall. It's still unused.

Guess I'd better give it a whirl.

 

[escapefjrtist]

TBS is checked at every spark plug change, 8K with the standard plugs and now at 16K with the Iridiums. For some reason I can't explain, the GEN II's hold sync better than GEN I's. This has been repeated several times at our PNW Tech Days, the newer bikes seldom need any adjustments. :dntknw:

I check mine at idle and then again at 3K ish. More often than not, there's not a lot of difference. YMMV

--G