Clone 6.5 - Level 1 Modified from NR Racing

Marlinmate

Marlinmate

Member
#1
#1
Hey there....I've got a yellow 6.5 Clone from NR Racing with the level 1 mods...to include a CL1 Cam, OHV 6.5 Race prepped including, Open Element Air Filter adapter & Filter, removal of governor, 18 lb Valve Springs, Small fan, Advanced Timing, and Rejetted carb. I'm not running an air filter due to the frame and engine location, but do have a screen/mesh covering the intake.

When i first ran it, the garage smelled like fuel, and the exhaust was leaving black soot all over the bottom of the seat and fender. The other issue I was having (and still have) is that when I give a little throttle (about 1/4 throttle) the engine misses as it's accelerating. brrrrrrrrrrrap....badaaaapa.....badaaaap......brrrrrrapp.....etc.

Based on some advice, I went to a smaller jet figuring it was running too rich. Fuel smell isn't as bad, but engine still misses/stutters/sputters and still have black soot.

Any ideas on what to do next?
 
Marlinmate

Marlinmate

Member
#6
#6
Thanks for the advice...changed out the oil....and found the oil was like black water and smelled like fuel.

Drained it and replaced with fresh oil.......fired it up....:scooter:

and still missing/sputtering.:shrug:
 
old-timer

old-timer

Scamming Member
#8
#8
Sounds like it still may be running to rich. I had a modded Predator that I messed with for quite awhile to find the right jets to make it run like it should.
Pull the spark plug and see what it looks like. That can tell you alot .
 
C

chazdaddy

New Member
#9
#9
Hello Marlinmate,

I have Harbor Freight 6.5 clone I race on a kart. It has CL1 cam, approx 27cc combustion chamber (I cut the block approx .040"), ARC billet flywheel, ignition advance to approx 27 degrees, aftermarket air filter adaptor, .038 main jet, RLV header and muffler (not wienie pipe).

The engine runs great on the track, but idles bad. If I turn down idle it will die, so normally have to idle approx 2000 plus rpms to get it on the track. Approx 2500 rpms it sputters bad, runs very rich. But racing, it runs great. :thumbsup:

I listened to your vid, sounds OK to me.

You do have a problem, if you are getting gas into the oil. Check the inlet needle and float, make sure it's not flooding the carb bowl with gas. I check the inlet needle by taking the carb off the engine and blow through the fuel inlet. It should allow air to enter the carb. Then, turn carb upside down and blow again. It should stop air from entering the carb. Check the float, make sure doesn't have any gas in it. If the carb float has a leak, it will fill with gas and not float, causing the carb to flood.

Like joekd said, call NR. Good luck.
 
Newoldstock

Newoldstock

New Member
#11
#11
Kart engines and minibike engines have important differences.

I had the carb troubles too.
I could never find something with a wide enough range and ease of adjustment.


You need a carb with lots of adjustment.
You have to understand how it works.

If you like slide carbs and you are good at tuning them then feel free!
But be aware RACE carbs are generally built to race and do not ride well.
They race not ride.....

You will have to play with the jetting of no matter what you try.

Sometimes you find a carb that works in the strangest place.
http://www.youtube.com/watch?v=PQ9U7flWop0&feature=c4-overview&list=UUYOkJf0MwNLWnL6CeCQLqYA
 
Last edited:
Marlinmate

Marlinmate

Member
#12
#12
Pulled the plug

I put on a brand new out of the box carb, and still am getting the mid range sputtering

I pulled the plug and this is what she looks like.
It's an F7RTC and is gapped to .033

Thoughts, ideas or suggestions?
 
minibikin'

minibikin'

Sho-nuff
#13
#13
Are you certain you have the gaskets installed correctly? I had a friend with similar trouble trouble and I believe the gaskets were on backwards or reversed or was using an unnecessary one. It sure looks/sounds like a vacuum leak.
Can you post a video?
 
Dragbikemini

Dragbikemini

#14
#14
just went over thread. recheck valve lash? what after market air filter are you using? if no matter what carb or jet your using you end up with same thing would mean mechanical. not a tuning problem. Coil air gap? carb gaskets and isolator are all in order? L
 
Marlinmate

Marlinmate

Member
#15
#15
minibikin' said:
Are you certain you have the gaskets installed correctly? I had a friend with similar trouble trouble and I believe the gaskets were on backwards or reversed or was using an unnecessary one. It sure looks/sounds like a vacuum leak.
Can you post a video?
Click to expand...
Click on the pic in post #4...it will play a video
 
creia

creia

#16
#16
Did you ever contact NR? If so, what was THEIR reply? If not WHY not?
If I were you, I would insist that they help and make this engine run correctly. What did you pay them ?
Michael
 
Marlinmate

Marlinmate

Member
#17
#17
creia said:
Did you ever contact NR? If so, what was THEIR reply? If not WHY not?
If I were you, I would insist that they help and make this engine run correctly. What did you pay them ?
Michael
Click to expand...
Yep...Contacted NR Racing and Russell gave me a few things to try and said if it's still not running right.. to send it back for him to work on.
 
Marlinmate

Marlinmate

Member
#19
#19
Dragbikemini said:
Oh man! Just reread posts again. What is the "screen mesh" your using? Take it off don't worry about dirt for now and try it. Could be choking engine.
Click to expand...
Hah..that mesh is nothing more than a piece of my wife's black, oversized panthose :eek:

I ran it this afternoon without it on, and still did the same thing.

Someone tell me what order the carb gaskets are supposed to be. Thin green one was at the back of the carb....thicker metal one was in between carb and air intake
 
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