Roketa Slow to Accelerate and Reduced Top Speed By ryand9 (Read 10,683 times)

[sprocket]

Tough one... I would look at the variator weights... over revving the engine a 70 mph may have got one sideways. It is load related so that points to the CVT...

[ce]

You might have joinked the diaphragm or joogled the needle when you hit Warp Speed.

Open the top of the carb and look into it., there may be a tear or hole in the rubber.

Also look at the wires connecting the coil and spark plug, and check all vac lines for leaks or loose fit.

As hard and fast and furious as you're running, you may just need a bigger main jet, I'd start with a 110 assuming you have a 105 now.

[crankin]

ryand9, I have the exact same problem currently; maybe we can team up if one of us finds a solution before the other? Was on my way home from work, it was really hot out (110 °F) last week and all of a sudden I had slower than normal take off speeds and top end speed is around 40mph when it was 55. I have a Motorbravo LKY Hornett (upgraded to a 160) . Its a 2009 model that I bought in June of 2011 for $900. He only had 300 miles on it. The previous owner had upgraded the variator to a Dual Ramp DR2 which he purchased here (pretty cool variator) www.shop.kidnmekarts.com/Variator-DR2-GY6-150cc-Variator-DR2-GY6-150cc.htm . As soon as I get a chance Im going to take the variator off and look for bad weights or bad Glide Keys. I did notice that when I took the bike out for a spin with the variator cover off, that the belt was not brought all the way to the outside of the pulley like it should (this is on the variator end not the clutch end), however when it's up on the dual kickstand, the belt does move all the way out like you'd expect. I'll keep you posted as to what I find out.

[ryand9]

Thanks. I will post if/when I get this thing running again.

ce: I checked the carb again and everything is fine, no tears or holes. I don't plan on going that fast again once I get this fixed, now that I know this is what happens. I checked the vac lines and everything looked ok. There were no cracks in the lines and the hoses are still clamped on. I haven't checked the spark plug yet, but the seller stated the put in a better spark plug as part of their assembly process before sending it to me.

I am about to throw my hands in the air and try and find a mechanic to work on it, but I really don't want to do that. Any help is much appreciated!

[ce]

OK, check the spark plug and the connections to the coil, make sure the plug wire is screwed onto the coil securly.

CDI new
CVT checked
Carb checked
Valves checked

Check fuel petcock or pump and fuel filter, it may be in backwards, the large end goes toward the carb.

[ryand9]

I am new to this. I can change spark plugs in lawn lowers and cars, but where is it on the moped and how do I verify it is working like it's supposed to?

[ryand9]

I found the spark plug. I am setting the gap on it. The manufacturer said that may be my problem.

[ryand9]

It wasn't. The spark plug was in good condition and set between 0.6-0.7mm like it was supposed to.

[ryand9]

Ok. The dealer finally gave up and gave me the number for the suppliers tech support. He seems to think I overheated and damaged the head gasket. He told me to run a compression test through the spark plug port and if it didn't hit 120psi or greater, that was my problem. Auto stores that loan them out don't have the right size and the motorcycle shop around me wants to charge me by the hour for them to run the test. Now I am in search of a way to get a compression tester to use for 5 minutes without being charged.

[ryand9]

In the event I do have to change my head gasket, does anyone have a step by step description or helpful video?

[crankin]

Have you tried to ride your scooter with the cvt cover off and watch the belt to make sure it is coming all the way out, to the outside of your variator pulley (front pulley) and compare this to when it's propped up on the kick stand?
I figured out what the problem is on my scoot as I thought it might be engine compression as well. The splines on the aluminum variator fan/pulley were worn off. The bolt was tight and holding it on so that's why I could get up to 40mph but not any better than that because since it was underload(me riding on it) since the splines were worn off the shaft couldn't rotate the variator fan/pulley as fast as what it should have if the splines were there. Easy Fix. I have ordered in a new one and I think this will fix it. I also noticed that my clutch was rotating a little lopsided inside the bell. Got that fixed by replacing the torque spring (which was on backwards anyway) and using a impact wrench with 1 1/2 six point impact socket to tighter her all the way down.

[ryand9]

I ran the compression test and it only came up to 100. I was told to remove my engine and mail it back to the dealership. They are going to rebuild it and send it back to me.

[Kaveman]

Bummer ! Hope they don't ream you bigtime costwise for getting it rebuilt.
will

[ryand9]

I am still under warranty so I only have to pay shipping. Now I just have to figure out how to get the engine out!

[sprocket]

You may want to get a price for the rebuild first...it may be cheaper simply to buy a new engine...

Find out what is covered under warrantee...many people think labour is covered then they get a $650 bill...