Novarossi 21-5 plus tuning questions

[KryptoRoxx]

Ok I picked up a used nova engine after I checked it out. Everything seems good and even runs pretty well......but I'm having problems with the tuning and I'm pretty new at this.

First problem and my solution= After I installed it and ran everything it had a huge dead spot in the throttle where it would almost kill it. First I thought that it was running too lean. Apparently that wasn't the problem and it was too rich. So I started solving that and now I have a problem that with out of 20 starts 1 or 2 will be started backwards!!!(????)

Second problem which I have no solution for=Possible culprits is a sticking clutch or possibly a incorrect slide problem on my carb. At times the engine will be at a high enough rpm that the clutch should engage but nothing happens. Pretty sure that it's a sticky clutch but I'm not sure how to adjust it (if I can)

BTW this engine does have a ton of torque. Very happy with the power and everything but if I could iron these two problems out to a smooth linear power then I would be very very happy with this engine. Any help is very much appreciated. I've only been doing this for a couple of months so if you have questions about my problems I will try to answer them to the best of my ability.

 

[MotoGod]

Check the direction that your bump box is running. I had mine running backwards when I first started in Nitro...caused me a TON of headaches ;-) If it's running backwards, swap the wires. When looking directly at the end of the crankshaft, your engine should be turning counter-clockwise when running.

As far as the clutch issue goes, there are a few things to check out.

1. Are the shoes too worn out? If so, replace them.
2. Is the clutch bell full of junk on the inside? If so, clean it with some sandpaper to get the stuff off of it, or replace it.
3. Are your clutch springs any good? Pull off the bell and operate the springs to see if they are smooth.
4. Do your clutch shoes have worn edges hanging down off the sides of the shoes? If so, dremel them off to make the bottom and top of the shoe (when installed) nice and smooth so it won't catch on anything.
5. Is your flywheel 100% tight or is it maybe slipping on the crankshaft? If so...tighten it.

Give that stuff a try...see where it leaves you and report back. We'll try to help as best we can.

 

[KryptoRoxx]

I actually solved it!!! I checked out my clutch though and I might need some new clutch shoes here in about a couple of months. The problem though was with the carb needle setting. I'm not entirely sure on how to explain it without using foul language. But instead of slowly coming in and out it was ramming the needle in and out with almost no difference between full throttle and no throttle. Man this engine rips!!!!! Now I have a few more minor adjustments and I'll have this baby smooth as a whistle. Thanks for the tips on the clutch though. I think with this new engine setup I might go through a few more than before. It's got a fironi sliding clutch on there right now (came with the engine) and it works pretty well. No more starting backwards issues either. I'm going to take her out to the track tomorrow and see how she does......and tune her out there.