YD3203 Acceleration Issue: 0-15 mph is ok, after that takes a while ?

[Tonyzsi]

I have tons of questions/issues so I'll list them all. Not sore if I should put up a different post for each or if 1 is better since they might be related.

I have a Yerf Dog 3203 with the predator 212 on it. I put installed a new jack shaft and chain on a 9 tooth jack shaft gear since I wanted quick acceleration and wasn't as concerned with top speed since I have little kids. I usually ride 1 or 2 kids around on the kart so there are 250-300 lbs. of combined rider weight.

My problem is the kart seems to accelerate ok up to ~15mph, but then it takes a while for the kart to reach a top speed of ~25 mph. On grass I'm not even sure it goes above 15-18 mph.

Do you think I need to clean the old torque converter? Could that be getting hung up until the engine slowly climbs to full rpms? Could it be something else?

I'm also having problems with the motor now that I installed the cone air filter w/ adapter. The engine has a lot of hesitation in it now that I didn't have before. I bought a #35 jet, but haven't installed it yet. Do you think that should correct my hesitation/ rough running motor?
I saw someone that had both the oil breather tube & tank breather tube connected to a plastic T that they put a mini-filter on. I found the mini-filter on Amazon for ~$5, but where can I find that T as I can see the tubes are different sizes.

I want to install a tach, but I'm not sure which one is correct as there are so many of them! I think I saw someone post that this is the correct one, but it only has 5 1/2 ft. of wire and I'd need at least 8'. Can I just crimp on another 3' or will that throw the tach off?
http://www.ebay.com/itm/Spark-Plugs...cle-Bike-MG-/181700702473?hash=item2a4e34b109

Thanks!
-T

 

[OzFab]

I have tons of questions/issues so I'll list them all. Not sore if I should put up a different post for each or if 1 is better since they might be related.

You did the right thing posting everything together, that's what we like to see

I have a Yerf Dog 3203 with the predator 212 on it. I put installed a new jack shaft and chain on a 9 tooth jack shaft gear since I wanted quick acceleration and wasn't as concerned with top speed since I have little kids. I usually ride 1 or 2 kids around on the kart so there are 250-300 lbs. of combined rider weight.

My problem is the kart seems to accelerate ok up to ~15mph, but then it takes a while for the kart to reach a top speed of ~25 mph. On grass I'm not even sure it goes above 15-18 mph.

Do you think I need to clean the old torque converter? Could that be getting hung up until the engine slowly climbs to full rpms? Could it be something else?

It does sound like the TC is not shifting, perhaps a good clean/overhaul is in order; here is a thread to help you with that...

Weight & drive ratio could also be issues; you told us the size of the JS sprocket but, you didn't mention the axle sprocket or rear tyre sizes...

I'm also having problems with the motor now that I installed the cone air filter w/ adapter. The engine has a lot of hesitation in it now that I didn't have before. I bought a #35 jet, but haven't installed it yet. Do you think that should correct my hesitation/ rough running motor?

A hi flow air filter does just that, it lets through more air; an engine needs the correct air:fuel ratio to run efficiently; by allowing more air in, you also need to allow more fuel in; fit the bigger jet & the problem should disappear...

It may also be worthwhile fitting a better exhaust; there's no point allowing the engine to breathe in if it can't breate out...

I want to install a tach, but I'm not sure which one is correct as there are so many of them! I think I saw someone post that this is the correct one, but it only has 5 1/2 ft. of wire and I'd need at least 8'. Can I just crimp on another 3' or will that throw the tach off?
http://www.ebay.com/itm/Spark-Plugs...cle-Bike-MG-/181700702473?hash=item2a4e34b109

Thanks!
-T

That's an age old question which I cannot answer as I have not investigated the issue enough so, I'll let someone else respond...

 

[Tonyzsi]

Thanks Fabroman!
I thought that might be the case, but wanted to check. Thanks for the link to the post on cleaning it. I also watched a Youtube video on it so it seems fairly straight forward.

I have the stock 60T axle sprocket and 20" rear tires. I thought putting the smaller 9T jackshaft sprocket would lower my ratio and help more, but I think something is holding the kart back. The TC makes sense as even when the engine sounds like it's turning pretty good we still just put along at ~15 mph. The GPS speedo on my phone eventually reaches 25 and even hit 27 once, but it takes a good bit of road to get there.

I'm going to order the 1" Go Kart Exhaust w/ Screw on Muffler Predator 212cc @ OMBwharehouse. I'm also ordering the AR3910X Racing Spark Plug.
Hopefully the jet will help my current problem and adding the plug & exhaust will really help the Predator 212 scream! I've read advancing the time would also help the engine run more smoothly, but doing that is outside of my comfort-zone.

Thanks again!
-T

 

[Tonyzsi]

What a different kart!! I installed the #35 jet and a Boxstock header and screw on muffler. The engine runs great and I can feel the extra power!

The engine was running better, but the kart still didn't accelerate smoothly. I removed the TC Driven, cleaned it all up, sprayed some dry lube on it and put it back together. Problem solved! It accelerates quicker and smoother from 0-26 mph (I have 9T jackshaft gear & 60T axel w/ 20" tires).

I'm loving this kart, but plan to continue to address other issues it has. I've been reading about Ackermann steering and I'm hoping to address that some how. Does anyone have any recommendations on new front tires that will help with handling? I drove the kart home in the rain the other day and almost lost it since it did not turn! The front wheels completely pushed I had to slow way up to make the kart turn. It reminded me of driving my old Probe GT in the snow once with performance tires on it. Not fun!!
Thanks for everyone's assistance in helping me get this YD3203 sorted out!