Fuel Mixture Not sure if running too lean, or too rich, or perfect?

[Rolling2High]

racing carb? deltoid copy runtung $20 which

I run that much oil in ohio and have to run a #6, a little hotter, to keep the plug looking right.
Ain't tuning fun?
It's all part of the hobby. A well tuned engine is its own reward.

Jets go in this and which one comes from factory? ??

 

[Slogger]

Jets go in this and which one comes from factory? ??

My kit came with about a 70 jet.

 

[Waxxumus]

With a Dellorto SHA clone you have to customize it to change its low and mid range jetting. Read how I did that to mine at http://www.dragonfly75.com/motorbike/SHA.html

How does changing its low and mid range jetting affect top end?
My low and mid are fine.

 

[Waxxumus]

Well since this post, Im still riding around on a BPR7HIX, and im still coming out black.

My intake had a leak, re bolted it on and my engine started running quite rich. (assume due to fix of air leak)

I switched the jet on my RT carb from a .70 to a .65.

It went from being able to hit 21 to 26 mph.

Startup takes quite a few rollovers of the engine to start compared to when I had the .70 in, but it feels like it runs better at high RPM, and runs great once warmed up.

I might have to add that 3rd hole down near the bottom of the jet needle to get more gas into the low end. But its weird.

She is still running too Rich.
My plug comes out black every time I clean it off. No smoke, barely any smell whilst running.
She only gets up to about 190-210 F most on a real hot day after being held at WOT for like 10 minutes.
Im basically 500 ft above sea level and running at about 85 degrees Farenheit.

I have no smaller jets, i could order some, but i honestly dont think that would fix this.

Any suggestions?

Should i go out and test with a BP6HS?

 

[Slogger]

If it's still too rich the thing to do is jet it leaner. My CG (all stock with an NT or the RT) takes a .60mm jet.
As long as your plug is dark and sooty, you're ok to go a little leaner.

 

[Waxxumus]

welllllll, thats not nessicarily true. the BPR7HIX is rated for temps above 110 F.
And im riding around at 30 degrees below that.
First the plug, then the jets. We SHALL SEEEEEEE

 

[Slogger]

Uh, ok.

Party it on out.

 

[Waxxumus]

If it's still too rich the thing to do is jet it leaner. My CG (all stock with an NT or the RT) takes a .60mm jet.
As long as your plug is dark and sooty, you're ok to go a little leaner.

How far above sea level do you live and what is the average temp?

I would assume i might need to jet richer so close to sea level (5-8 hundred feet) as the diameter of the carb bore is 2 mm smaller than the intake.

Could be wrong. I think i might have accidentally enlarged the top hole on my delorto 14.12 and it has effected the mid a tad bit. All i really do is hold the throttle at about 30% and she will keep picking up speed. If i give it more gas than 70% it bogs out slightly after about 20 seconds of high rpm. /i may slightly enlarge the bottom hole, and add a tiny hole under it. then i can jet leaner as well without a problem, but it will be feel at that point rather than the equation used to figure out proper jet size.

 

[Waxxumus]

New news. Its always something with this bike.
Head bolts were at like 6 ft lbs. Tightened em up to 11.
My spark plug was torqued at about 10 ft lbs, so I torqued it up to 19 ft lbs.
Seems to sit alot deeper now... wonder if it stripped it :I or if it was supposed to be that torqued from the beginning...

 

[Waxxumus]

14 mm with gasket in an aluminum head = 18 - 21 ft lbs