72cc Stock carb and trans tuning.

[Meejacob]

Hey guys, so recently i just put together my Malossi 72cc motor and im having difficulty tuning it (Baka-san was right). Right now my jets are 40/94 needle in the middle. Here is my setup

Dd-Block (boost ported, and intake ported)
Zx trans with S clutch. (Perhaps that S clutch is the problem?)
Kelli pulley w/ 10g weights
1000 center spring w/ 2000 clutch
7.9 gearing
V8 pipe
Oil plug, Premix 32:1 Amsoil Dominator

Ok, yes i realize that 7.9 is probably too much gearing for a malossi cast but thats the best i could get for my DD block. Im having trouble getting this thing to speed. Based on the charts from another forum member, at 8500 rpm with 7.98 gears i should be around 60. Well that isnt the case. Ive been spinning around 8600-9100 and have hit a minor 54 so far. This is also within lets say .6 miles. What do you guys think i can do to get to that 60mph range? It may be a lot to ask with the 7.9 gears but I atleast want to be able to cruise 50-55 and hit close to 60-65 full tuck holding it. Havent had this much trouble tuning a bike in a while lol. Also noticed sometimes when coming to a stop my bike will idle high for a little and then drop back down to normal speeds.

My spark plug color changes every now and then but its mostly a nice chocolate/reddish brown. I noticed yesterday after doing a small .5 mile run that half of the spark plug was black/ DARK grey but they other was a nice brown.

I know i can get to atleast 65 because a friend of mine with a similiar setup on a heavier bike is doing it and hes using a yms 28 instead of the v8. Any help and input is greatly appreciated. Thanks.

[Red Eft Performance]

Hello 10g weights sound heavy for those gears. You could try lightening the rollers and see what happens.

[Meejacob]

Indeed they do sound heavy but its the only way i will even come close to removing the mark on the front pulley. I tried 7/8 gram weights and is was super revvy. Spun past 9500 but definately was no where near the speeds it should be at 9500.
Zx trans with a honda elite S clutch.

[bonesv]

Hey guys, so recently i just put together my Malossi 72cc motor and im having difficulty tuning it (Baka-san was right). Right now my jets are 40/94 needle in the middle. Here is my setup

Dd-Block (boost ported, and intake ported)
Zx trans with S clutch. (Perhaps that S clutch is the problem?)
Kelli pulley w/ 10g weights
1000 center spring w/ 2000 clutch
7.9 gearing
V8 pipe
Oil plug, Premix 32:1 Amsoil Dominator

Ok, yes i realize that 7.9 is probably too much gearing for a malossi cast but thats the best i could get for my DD block. Im having trouble getting this thing to speed. Based on the charts from another forum member, at 8500 rpm with 7.98 gears i should be around 60. Well that isnt the case. Ive been spinning around 8600-9100 and have hit a minor 54 so far. Any help and input is greatly appreciated. Thanks.

You say this has a stock DD carburetor?(similar to an sk50)
Also, do you have an actual tachometer installed? How are you getting the speed reading?
What size tires do you run?
Are you sure of the gear ratio?
What size belt are you using? It could very well be a cvt related issue.
Try an "S" length drive belt(15.5x30x641mm). Hope this helps you. GL!

[LMH]

[LMH]

Technically there can't be an absolute chart for rpm vs mph but it gives you an idea of where you should be.
10gx6=60g. Most of the time the Ma iron uses 48g total but it's all user preference. Now if the engines spinning faster than you think it should be there's gotta be a slip somewhere. Also keep in mind with a Zx trans you're gaining take off speed and losing top end speed. Wheels has had good experiences with a Honda metro belt I've heard.
How does it rev up rpm vs tire speed on the stand? Will it smoothly transition between the pulleys? You can check one of my old YouTube videos for how a Zx trans should operate smoothly. I have the cover off during the video so you can see both.

[LMH]

Also if its idling up when coming to stops you're either running lean or there's an air leak. You can try moving your needle up 1 spot. Or enlarge the pilot or tune the pilot more rich.
Those dd blocks like to leak out the stator side seal I've seen and heard many times.
The stock s clutch is the same as a Zx clutch.

[LMH]

[paulpauly7]

no one understands your babble fdns .Can somone please ban this guy he is filling this place up with useless text that doesnt make sense.New people to this site doing a search have to scroll thru pages of mindless babble .DELETE HIM and put a ban on his ip address so he dont come back.

[bfowler]

Hey honda what's your YouTube channel? Curious to watch some videos and listen to bikes. It'll help me listen to my own bike and help me see if it's running right. Thanks a lot. Sorry about the off topic post!

[Wheelman-111]

Greetings:

Fnds finds himself thinking his anti-Semitic, homophobic thoughts alone again, naturally. Or perhaps he's engaged in a Round Table discussion with Trains 420 and several other Forum persona we've eventually had to ban, always for a pattern of escalating pointless pugnacity. The trouble is he knows enough about computers to succeed in returning from a different Proxy each time. Hour behaves well for a while, but his typing and scrambled ideas give him away. Eventually someone offends his dignity and he goes off with a racist or otherwise offensive post and is banned, only to start over. I believe he's smart in some ways, but feels compelled to try to prove himself smarter than everyone else. It must frustrate him not to be able to construct a sentence coherent enough to convey his ideas. If only he applied himself to something useful, the world would be better off.

[bonesv]

Well, just curious if the belt makes any difference?

[Wheelman-111]

Greetings:

Every engine build seems a little different, but for what it's worth I've never had much luck with the V8 pipe. It grinds out oodles of torque off the line, but tends to run out of breath as the Revs climb. Consider a PG Short or other pipe - the Short's not much louder, but lets it run on up above 10K with decent torque. That's where the speed is.

[Meejacob]

Technically there can't be an absolute chart for rpm vs mph but it gives you an idea of where you should be.
10gx6=60g. Most of the time the Ma iron uses 48g total but it's all user preference. Now if the engines spinning faster than you think it should be there's gotta be a slip somewhere. Also keep in mind with a Zx trans you're gaining take off speed and losing top end speed. Wheels has had good experiences with a Honda metro belt I've heard.
How does it rev up rpm vs tire speed on the stand? Will it smoothly transition between the pulleys? You can check one of my old YouTube videos for how a Zx trans should operate smoothly. I have the cover off during the video so you can see both.

Thats what i was thinking, 60g is indeed far to heavy. I did try 7 and 8g weights but it was way to revvy. From there i worked my way to something more tame and consistent. Baka-san believes that running the v8 with the stock carb is too much, not enough carburation to run an after market pipe. I have yet to run it on the stand but i will try today with the kicker cover off. Also will check for leaks, that high idling at a stop for a little gets pretty irritating haha.

Greetings:

Every engine build seems a little different, but for what it's worth I've never had much luck with the V8 pipe. It grinds out oodles of torque off the line, but tends to run out of breath as the Revs climb. Consider a PG Short or other pipe - the Short's not much louder, but lets it run on up above 10K with decent torque. That's where the speed is.

In the past ive had a pretty good experiance with the v8 on my past builds but they werent with the stock Carb. I would use those pipes but because i only have the stock carb on (plan on leaving it) Im going to try and get my hands on a Goshi pipe.

[Meejacob]

Been playing around with my motor lately and have gotten it to 63.8 per gps. This was slight downhill with head wind. Got a flat tire yesterday so I will be tinkering with it some more haha. Going to try and swap out my 1000 center spring for a stock one and see how it is.