'Unauthorized' TB synch

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Ok, so after long (few years) hesitation I finally did the job today, took me 3 hours in the morning and some angry glimpses from neighbourhood...

However, it was not at all as straightforward as I expected it to be from the writeups.

According to 3dogs above, you should balance the cylinders during slow rev-up of engine. Well, the issue with my engine was that the balance between the cylinders changed while revs increase: for example, the 3rd was lower than 2nd at 3000 rpm but became higher when reached 4000 rpm. A bit the same between 3/4 and 1/2. So after hours long screwing I more or less got them all pretty similar, just 1 unit (Carbtune) difference, but the balance kept changing together with rpm. And for me a steady high rpm gave better adjustment opportunities than the reving-up.

And then also the idle syncing affected on the balance on high revs. I started with idle bypass screws closed, synced the high revs as good as I could, then did the idle sync, after which the balance on high revs had already changed, so needed to be adjusted again, after which the idle balance was changed, so did that again, and so on and so on at least 5-6 times until I finally got them all more or less in good balance. But as said, the pattern of different cylinders being higher on different rpms did persist. Especially between 3000 and 4000 rpm, the the showings on around 2000 were completely nuts, but I disregarded it as never use such rpm while driving.

It is also often recommended (Fred W) to do the syncing while bypass screws closed and on idle speed. In my case they were pretty out of balance on idle, but not in the same pattern while on 3 or 4 krpm. So for a while I was thinking which is more important, the balance on idle or on high revs, finally decided to do it for high revs as that is where I mainly drive. Don't know if that was a wise decision. Am going for a month long trip in 2 days, I am sure I will find it out then.

 
Went for a short ride but did not feel much difference with the situation before. In fact, I start feeling the vibes only after a day long drive, so it has to be seen. By the way, the adjustments altogether were not more than 1/2-3/4 turns per screw, so not sure how much in the end did I change anything.

 
When I attempted this sync last fall, I encountered exactly the same thing, vacuum levels would vary significantly at different RPMs. I did as you did, optimizing around 3-4,000 at the expense of balance at idle and low RPMs.

One of the things I will try this spring is to clean the TBs as best I can and try again.

And then also the idle syncing affected on the balance on high revs. I started with idle bypass screws closed, synced the high revs as good as I could, then did the idle sync, after which the balance on high revs had already changed, so needed to be adjusted again, after which the idle balance was changed, so did that again, and so on and so on at least 5-6 times until I finally got them all more or less in good balance. But as said, the pattern of different cylinders being higher on different rpms did persist. Especially between 3000 and 4000 rpm, the the showings on around 2000 were completely nuts, but I disregarded it as never use such rpm while driving.
It is also often recommended (Fred W) to do the syncing while bypass screws closed and on idle speed. In my case they were pretty out of balance on idle, but not in the same pattern while on 3 or 4 krpm. So for a while I was thinking which is more important, the balance on idle or on high revs, finally decided to do it for high revs as that is where I mainly drive. Don't know if that was a wise decision. Am going for a month long trip in 2 days, I am sure I will find it out then.
 
I ran through this procedure and while it cleaned up the vibes at steady RPMs I'm fairly convinced it vibrates more during hard acceleration. I'd have to go out and ride it to verify, but I'm thinking it starts around 2500-3000 RPM with the throttle more or less wide open. I don't really remember it doing that last fall, at least not to that extent. Hard to tell the exact change as I did it early this spring after pulling it out from winter storage. Also noticed a little popping on hard engine braking before the engine is up to operating temp. Never noticed that before the TBS but I've only owned the bike since late last summer. Any thoughts?

 
Popping on engine braking is due to the PAIR. Any bikes that still have the PAIR installed will pop. It doesn't hurt anything, it's just the unburned gasses being ignited in the Cat.

I don't see how doing a throttle plate alignment would cause increased vibration while accelerating unless you screwed it up.

 
Removed the PAIR and installed the Wynpro plates the other day, did the sync after that again, bike seems to run smoother than ever. No popping.

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