[Rocksnap]

Originally Posted by PJMac

We had exactly this problem. Clogged exhaust. Apparently they make these quiet by packing a lot of insulation in the muffler. It can work itself loose. Replace muffler.

Do not remove spark arrester. Can’t believe I had to say that.

Seriously, why not? Spark arrestors were put on by lawyers.
It’s not like our well watered golf courses are going to burst into flames.
I’ll bet many/most carts on course don’t have one. Older ones anyhow. It’s also one of the first things I did to my brand new, now one month old cart. I chug up the hills at 20mph. I’d call that a win win.
But yes, the OP has a spark arrestor issue or a clutch/belt issue. By the symptoms, I’d say it’s a clogged spark arrestor.

We have a 2024 Quietech and I have noticed the same issue on the bridge at Spanish Springs.

[Raybemis1]

Drive belt

[Tyrone Shoelaces]

Quietechs are just plain slow on acceleration.
Which could be a problem when being followed by modern electrics
I get frustrated driving one as I'm used to the cart getting out of it's own way.

[mkjelenbaas]

Originally Posted by SteveCanada

A 2017 Yamaha quiet tech.. runs great at 21 mph on flat but slows on incline .. going over bridge at Spanish Springs slows to 5 or 6 mph on steep incline .. is this normal or is my belt needing change etc ? thanks

SO NOT TAKE INTO THE CILLAGES GOLF SHOP AS YOU WILL GET SCREWED! Call Willies golf repair and they will come to your home for an easy fix - I have had this happen to me and it has to do with muffler - a $59 house call and minutes later your fixed!!

[mkjelenbaas]

Originally Posted by CarlR33

Ever had any maintenance done on this vehicle like a belt change? If not, that may be your answer?

The problem is called “spark arrester” - not the belt!

[mkjelenbaas]

Originally Posted by mrf6969

You need to remove the spark arrestor. A spark arrestor screen is a device designed to prevent fires by stopping sparks or flames from escaping. There are two common types:
Screen type: Uses a metallic mesh to prevent large particles from leaving the exhaust system. Commonly used on motorcycles, ATVs, golf carts and small engines.
Known to cause your issue.

THIS IS THE ANSWER!! Do not accept anything else - if you do your getting scammed!!!

Originally Posted by mrf6969

You need to remove the spark arrestor. A spark arrestor screen is a device designed to prevent fires by stopping sparks or flames from escaping. There are two common types:
Screen type: Uses a metallic mesh to prevent large particles from leaving the exhaust system. Commonly used on motorcycles, ATVs, golf carts and small engines.
Known to cause your issue.

Is this used to prevent fires onboard the cart or to the environment.
Will this definitely improve tourque on steep grades?
Also, any risk of damage to the cart?

[polirudb]

I had the same issue and one of the local companies came to my house and removed the spark arrestor without telling me what they did. There was definitely a big positive difference in performance, especially crossing the Water Lilly bridge. The noise from the cart however was almost unbearable. I called them back, and at the time they told me the only solution was to put the spark arrestor back in (which again I did not know they had taken out). When I told them to put in back in, they told me the cost would be about $700.00, as a new spark arrestor is only sold with the muffler assembly. After much back and forth, they finally "found" me a spark arrestor (probably one they removed from someone else's cart), installed it in my cart, and my problem was solved. Bottom line, in may case, removing the arrestor improved performance but increased the noise the cart made to the point that it was no longer a "quiet tech". Cleaning it, if possible, or poking holes in it as some have suggested, may be the best answer. Good luck!

[MCJEFE]

Nailed it!!! This is exactly what I would recommend. My son at Bo's Buggies, 352 933-3441, does the spark arrestor removal and secondary clutch spring replacement all the time. It's a very common issue with the Quietech's.

Call him if you don't have the correct tools or experience. A clutch spring is under a lot of pressure and can be dangerous.

Originally Posted by tophcfa

Definitely could be the spark arrestor. In general, QT’s don’t have a lot of power relative to other carts since they have a smaller HP engine as part of the design to make them quiet. Also, the spring in the secondary clutch is designed for golf course use where the carts don’t go more than about 12-14 MPH. Yamaha adds high speed gears to their Personal Transportation Vehicles used in the Villages, but doesn’t modify the clutch spring. Adding the high speed gears increases top end speed but can compromise torque (start up speed and hill climbing power). An easy modification will solve the problem, which involves putting a stiffer spring in the secondary clutch and replacing the belt with a premium aftermarket drive belt. I did the modification to our QT using the green spring and premium belt available from powerequipmentman.com and there is a noticeable performance difference (not top end speed, just torque). The website also has an excellent YouTube video showing how to do the modification. It does require some basic mechanical knowledge, and two specific tools that most people don’t have, a clutch compressor and a snap ring tool. My neighbor up north loves to fix stuff and helped me fabricate the clutch compressor and let me borrow his snap ring tool. I’m very happy with the modification, but the cart definitely was a little jumpy for a couple days until the new belt broke in. I keep the old belt in my cart as an emergency backup and hope to be able to use it someday to help someone stranded with a broken belt.

Regardless of the problem, it’s a good idea to remove the spark arrestor next time you change the oil and you have easy access to it. You will be eliminated a potential future problem that is only there because of a stupid California requirement. The cart will run better and you will only notice a slight increase in noise when driving through tunnels or alongside a dividing wall.

[Topspinmo]

OP did not give enough information to diagnose the problem other than guessing. For it to be belt it has to be slipping which usually creates squealing sound unless contaminated with oil creating unusual high rpm when cart seems to be not up to speed. Going up the bridge if belt was slipping the there would be squeal (unusual noise) and rpm’s would be why high or on the max governed setting. Belts can be visually inspected and measured. It should be obvious if belt slipping signed heat and belt deterioration therefore needs replaced.

The spark arrestor for one blocks exhaust gases from escaping even when new anything restricting exhaust means air coming in has harder time going out. So if cart seems to be sluggish and engine rpm struggles to get to governed speed first thing to check spark arrestor. Some try to clean it, just going to restrict again eventually, some option replace it when cost couple hundred dollars with same problem returning in 3 to 5 years. And yes it will restrict exhaust again causing same problem. Some elect to remove restrictions by punching or drilling out screen therefore eliminating problem for carts life. So there the options if it actually is the belt or the spark arrestor. Most likely it’t the spark arrestor blocking exhaust gasses lugging the engine down.

[Topspinmo]

Originally Posted by polirudb

I had the same issue and one of the local companies came to my house and removed the spark arrestor without telling me what they did. There was definitely a big positive difference in performance, especially crossing the Water Lilly bridge. The noise from the cart however was almost unbearable. I called them back, and at the time they told me the only solution was to put the spark arrestor back in (which again I did not know they had taken out). When I told them to put in back in, they told me the cost would be about $700.00, as a new spark arrestor is only sold with the muffler assembly. After much back and forth, they finally "found" me a spark arrestor (probably one they removed from someone else's cart), installed it in my cart, and my problem was solved. Bottom line, in may case, removing the arrestor improved performance but increased the noise the cart made to the point that it was no longer a "quiet tech". Cleaning it, if possible, or poking holes in it as some have suggested, may be the best answer. Good luck!

Probably could be cleaned if someone has the ability?

Poking holes in it will increase noise level by less restriction of exhaust. In your case plan on replacing the spark arrestor ever 3 to 5 years cause it WILL plug up again. IMO eventually the noise will be less concern due to cost of new spark arrestor for most of us?

[Singerlady]

Originally Posted by SteveCanada

A 2017 Yamaha quiet tech.. runs great at 21 mph on flat but slows on incline .. going over bridge at Spanish Springs slows to 5 or 6 mph on steep incline .. is this normal or is my belt needing change etc ? thanks

Remove spark arrestor. California law. Our cart had the same problem. Runs great now.

[tophcfa]

Originally Posted by Wenham

Is this used to prevent fires onboard the cart or to the environment.
Will this definitely improve tourque on steep grades?
Also, any risk of damage to the cart?

The spark arrestor is designed to prevent a spark from coming out of the muffler and starting a brush fire. It is basically a fine screen that covers the end of the tailpipe. Over time, carbon deposits clog the screen and limit exhaust airflow causing performance issues. For the Villages usage, it is a worthless and trouble prone feature. Kind of like an appendix or wisdom teeth in a human. If all the idiots driving around tossing out cigarette butts hasn’t started any fires than spark arresters most certainly aren’t necessary. Removing the spark arrestor will only help climb steep grades if the one in your cart has become clogged. There is no risk of damaging your cart by removing it, but it would risk damaging your cart driving around with a badly clogged one. Hope that answers your questions.

Originally Posted by tophcfa

The spark arrestor is designed to prevent a spark from coming out of the muffler and starting a brush fire. It is basically a fine screen that covers the end of the tailpipe. Over time, carbon deposits clog the screen and limit exhaust airflow causing performance issues. For the Villages usage, it is a worthless and trouble prone feature. Kind of like an appendix or wisdom teeth in a human. If all the idiots driving around tossing out cigarette butts hasn’t started any fires than spark arresters most certainly aren’t necessary. Removing the spark arrestor will only help climb steep grades if the one in your cart has become clogged. There is no risk of damaging your cart by removing it, but it would risk damaging your cart driving around with a badly clogged one. Hope that answers your questions.

This is a brand new cart bought in August, the lack of power on inclines has been there since day 1.
I doubt clogging is an issue with mine.