Top speed and rpm loss?

[danlandberg]

A.G., I have not tried a jet change yet. I went about a block, it would not run worth a poop. I then changed the needle setting and that did the trick! It was new then so I was running 16:1. But I have thought about the air density thing. It has been hot here! When it was running good it was a lot cooler! It's another thing to think about. THANKS!! Dan

 

[arceeguy]

Air density plays a huge factor in gas engines. I burnt up a gas leaf blower when I got the "brilliant" idea of using it to blow some snow off of my walkway. It hasd all the symptoms of "lean bog", but dummy me kept on running it WFO. It finally quit after about 5 minutes. Cylinder and piston scored up.

With your altitude and hot weather, it is no wonder that your Happy Time isn't so happy! I would venture to guess that powersports dealers in your area have smaller jets in stock to keep the equipment they sell running right at that altitude.

Unfortunately, you kind of have to DIY with a HT engine.

I have read that Dellorto jets will fit the HT engine. Go to a MC shop and see what will screw in. A #72-75 might do the trick. I need to hog them out to #80-85 here in NJ. Stock is roughly #78

 

[danlandberg]

Thanks A.G. In the colder weather conditions, the air is denser. Causing a leaner condition, correct? Moisture has a role to play in this also (I think)? One problem in this town is, it houses just over 2000 people, so there is no real places to readily get such parts. So here it is DIY all the way! OH,! Does Happy Times sell the RAW engine? I got mine off ebay. Thought I got a deal when I opened box "RAW engine, cool". Then I read some threads later (didn't know about great sights like this till later) MY BAD!!!! I have a Dellorto sight in my faves. Just did not know what #jet might help!! In UT, It might take a suit case full, for every other day! They say "If You Don't Like The Weather In UT, Wait 10 Minutes It Will Change" So far in the last couple of days, over cast, but still HOT! I hit 25mph today. Still shy of top speed & mph. Now what?LOL

 

[DJEEPER]

Do you let it fully warm up before trying to break the sound barrier?

Check to make sure your pipe isnt clogged or anything.

 

[danlandberg]

I have checked the pipe, even took the end cap off (a little loud) & as it gets warm to hot, it actually slows down. I know with all the help on this sight, It WILL get it worked out!!! Thanks! I have tried almost every thing (except get a new engine, different brand/maker). That may be next.

 

[DJEEPER]

have you tried adding more oil? It might give you more compression

 

[danlandberg]

I Have a slant head, It will skid the rear tire trying to start it until it's warm. Compression seems good!

 

[DJEEPER]

or it might help you run cooler?

 

[danlandberg]

It might help it run cooler, True. I have had a lot of 2 stroke dirt bikes and one PUCH moped (in the early 80s). I have not tampered with the oil/fuel mixture to much ( every where I rode in So Cal was about the same climate) no need to, they did good to great (for me)!!!

 

[danlandberg]

But I got to say, This thing is starting to upset me! Only because I am a very mechanically inclined person. I have always mixed to suggested ratios, for what ever I am riding, and I have never had a problem with a 2 stroke like this problem!!! "I GOT The RAW Deal".