Just purchased an 01 LTA50 for my boy and it has the restrictor removed. I want to put it back in until he learns how to ride. What size washer (inside and outside diameter) do I need to buy? Can I just pick one up at the hardware store? Also, are there other restrictors that I should be aware of to put back in?

Thanks

 

I dont think they make much diffrence. just use the throttle limiter so it doesnt rev much.

 

The restrictor does not make alot of difference until you start making mods on it and needs the flow. Does this quad have an adjustable cdi, some do and work well other wise the throttle limiter is best other than if it is set too low the clutch won't pull up hills.

 

I'm not sure what a CDI is, so I can't answer that one, but I do know what you are talking about in referencet to not pulling up hills...this is exactly my problem. I have a lot of hills on my property, and right now, I'm trying to get him used to the handlebar brakes, so needless to say, going down the hills is my main concern. I was hoping that putting back in the regulator, it wouldn't let the engine run freely down hill (since it would be restricted by how quickly the exhaust would escape)...I guess I was hoping for a little pseudo-"engine braking". Right now, I have the throttle limiter balanced so that he can get the bike moving but limiting the top speed, but that is a fine line. And like you said, if he tries to start up a hill...good luck, because it won't do it. Can you add a bit more info about the CDI?

 

it wount give the engine braking like you are thinking

 

The CDI is the little black box under the seat. It limits the rev point on the engine. The LTA50 is different than the LTZ50 due to the different point at which the engine needs to rev in order to produce power (2 stroke vs 4 stroke). The CDI would not help in what you are looking for. Nor would reinstalling the stock restrictor. Those will only limit the rpm and clutch engagement on the bike. they have nothing to do with backpressure or being able to use the engine as a brake. If you are looking to slow your sons decent down hills aside from just the hand brakes then I would suggest running the tire pressure really soft. It will create more of a rolling resistance. The only other thing would be to do some simulated training with him to get him used to pulling in the brake levers.

To answer your question as to where the restrictors went, you have one that goes on the clutch variator assembly(about 1/4 inch thick) and one that went between the headpipe and exhaust that looked like a washer with a very small center hole which limited the amount of exhaust inturn choking the engine.

 

So by installing the washer back into the exhaust, will I be lowering the upper end rpms, essentially dropping the top end speed, or will I also need to install the restrictor in the clutch variator assembly? And by the way, what is that and how does the restrictor work in that location...I understand the smaller diameter on the exhaust side, but I'm unfamiliar with the clutch limiter. What do you think about installing a smaller restrictor on the exhaust side...will that lower my top end rpms even further, or will I eventually start to choke out the engine? I've already got him in "class"...doing some braking tests to get him used to that (he is too used to his PowerWheels motor braking and tends to forget that just because he lets off the gas doesn't mean it stops). He'll eventually get there...I'm just curious about things I can do to be more responsible for his safety.

 

One more thing. After installing the restrictor into the exhaust, I have been hearing a random ping from the engine...almost like the ignition timing is off or using the wrong octane or something. Could this have anything to do with the restrictor or is something else wrong with the engine or is it the nature of these 50cc beasts? I plan to change the oil and sparkplug for maintenance reasons, but I'm not sure that will help anything.

 

By installing the restrictor washer back in the clutch assembly, you are limiting the amount of engagement that the clutch will have. Thus, restricting the higher rpms and engine engagement. This will cause the bike to run slower at wot. The restrictor in the exhaust basically sufficates the air flow. So, if it has been removed, I'm sure the carb was adjusted to compensate for the free flow of exhaust. When you re install it you may have to detune the carb. That would be my guess as to why you here that pinging noise.
The best thing you can do for safety is to train your son. Set up cones and have him manuever through them. Sow him the hand signal for stop and practice it at various speeds. Repetition will be the best thing for him. The alternative is one good crash. Then he will understand the meaning of the hand brakes.

 

Makes sense. I pulled the plug yesterday and it was black. Installed a new one and the ping has gone away (at least while idling...it was too late for a test drive). Does that make sense that the plug would be black and the engine would be pinging...would have thought that it would have been lean. Yeah, I think i'm going to take the restrictor back out of the exhaust, and keep from having to retune the carb...best not to fix it if it isn't broken. It also seems from your note that out of the two options, the clutch spacer would be more effective at what I am trying to do. Know anywhere that I can get details on how to check if it is installed? And I totally agree with the training suggestion...have already started that and he's picking it up pretty quick.