Throttle sync issues. . . .

[0627Devildog]

While I know they make a "Throttle Sync" mechanism that "locks the throttles together, I prefer the throttles be independent of each other.

That said, with just over 10 hours on baby girl I noticed pretty early on that the port side engine needs a bit more coaxing to stay in sync with her starboard counterpart.

The throttles appear to be "together" for all intents and purposes. However the port throttle lever requires a bit more careful attention and minor position corrections to get her in sync with the starboard side.

They can vary by as much as 500+ RPM when "synced" side by side. I can always get them to the same RPM and humming along in unison, and when at WOT they appear good to go. But in the mid ranges soothing feels off.

Since the port throttle seems to "back out" of position I am wondering could this be a tensioning screw loose somewhere? Is there something I am missing? Or do these "just behave" this way?

 

[Craig]

Ours does exactly the same thing, port throttle will fall 3-500 rpm after you release it. Another thread explains the process to adjust tension on the throttle to fix this but I haven't had time to try it. I'll see if I can find the thread and post it up.

 

[Craig]

https://jetboaters.net/threads/throttle-dropping-check-here.299/

 

[bobbie]

will at jetboatpilot has a video showing the syncing of cables

 

[jdonalds]

I actually really like the split throttles. I choose not to have the engines close to perfect sync. Why? because they are most likely to resonate when they are close together creating a rolling mmm-mmm-mmm sound. So I will increase or decrease one engine or the other to eliminate that resonance.

 

[sysinu]

There's a lot of feedback as it relates to RPM differences between boats, throttle position, impeller, etc.

I think on purpose one of the impellers gets pitched differently than the other (there's a thread somewhere, if I wasn't in a hotel on my laptop I would go find it). Because of the different pitched impellers, you will only be able to sync your throttles position with the same engine RPM's at 1 RPM band (like WOT). I have the throttlesync on my throttle and it's always disconnected because of my impeller pitch. My dealer is in the process of getting me some new impellers, so my experience may be different as well, but my port engine is always less RPM than starboard and I will end up having the throttles in two pretty different positions initially to get the RPM's where I want them. My throttle cables are where they should be as well.

Also, if your impeller pitch, or your combustion system in general (air filter, plugs, etc) are different between the engines, throttle position or throttle cable length sync might not be the biggest player in why your RPM's are out of sync.

 

[billyb]

I can't wait for my ten hour service to get this resolved...problem is, I have four hard days of boating until that happens.

 

[Rigger]

The throttles on my newer AR240 SUCK!!! They are far worse than the throttles on my old SX230 and I did nothing to those. I've done everything I can think of just short of completely disassembling the new ones to try and make e'm even close to the old one's. Even my wife says yuk! If the dealer can't help Gaffrig throttles are for certain in our future.

 

[biglar155]

I purchased "Throttlesync" and I really like it. Maybe my favorite mod. If you want independent control you just slide the little switch to the left and you're back to split controls.

Can't speak for the new models, but on my boat I'm able to "twist" the Throttlesync enough to match the engine RPMs.

I've noted that this has pretty much eliminated having one throttle back off (it's been so long since I installed that I don't recall which one was the problem) because of the friction of the other throttle.

Your Mileage May Vary of course, but I find the boat much easier to drive with the Throttlesync locked.

 

[Glassman]

I prefer them unlocked and independent of each other. I tend to drive the boat more with the throttles than with the wheel when I'm going a long distance in a fairly straight line.

I can lean back in the chair and not touch the wheel for miles and miles that way. It's much easier on my neck and shoulders that way too.

Wanna nudge the boat a little to port to make the bend in the river? Easy, just bump up the starboard throttle, back off when you have changed a few degrees and your fine.

 

[Zarrella]

I love my Throttlesync. Keeps the engines in sync and with a quick flip of the button I can have them independent again

 

[jetboater4life]

In my opinion throttle sync is expensive for what you get, but IMHO worth it

 

[txav8r]

Marrying the throttles on a jet boat is only an issue when your getting used to it. After that, you won't worry with them near as much. I may be the odd man out here...but my 230 had the 500-700rpm drop after I let go of them. And they wouldn't stay up at all unless I was over 5000rpm's. The new 240 stays put even at 2500rpm's and they are really well sync'ed at all settings comparatively. But best of all, where I let go is where they stay, no dropping rpm! I can't say that I did anything or the dealer did anything to address this, I just got lucky I think. The friction set screws are pretty worthless IMO and I learned to live with the drop back. Glad I don't have to now! I also had the Throttle Sync on the 230 and I felt it was beneficial in helping to hold the dropping throttle, so they both stayed better at lower rpm's. Since I don't need it on this one, I won't get it.

 

[Zarrella]

I agree they are way over priced. I think of them almost like a cruise control in the sense that at cruising speeds it is nice to leave them locked so they act as one. But at slow speeds or while towing I always leave them unlocked so as to operate them independently.

 

[10-8]

I also have throttle sync, but I also took a different approach to syncing the throttles than the video. I guess one of my many faults is I'm a little anal about having engine RPMs between engines match at a given throttle position. Although the effect may be minor, 500 or more RPM difference at cruise means the boat is 'pushing' in the opposite direction from the higher RPM motor. So this is what I did:

On my model boat, there is a great deal of extra travel at WOT. WOT is reached before the throttle levers are full forward, so this method does not change the sync at WOT. I find best cruise is between 5k-6k RPM. So I engage my throttle sync and take the boat out and run to around 5500 RPM on the starboard engine. I note the difference in RPM between engines and then bring the boat to a stop. I then open the engine cover, and taking a small wrench unlock the cable lock nuts on the port engine throttle linkage mounted on the side wall. I then lengthen or shorten the adjustment slightly (it doesn't take much), depending if that engine needed more or less RPM. I then repeat the run to check again. A 2nd adjustment or more may be needed until you have the sync where you want it. If you want them a little out to cut down on the harmonics, you can do that too.

This does not effect WOT or wake mode, just the sync around the mid range. At least, that's what worked for me. Your mileage may vary....

 

[Sheldon DeVries]

Does anyone have a throttle sync for a yamaha they are willing to sell? Let me know - sheldon@jchurch.life