Engine Trouble 4 stroking?

[Slogger]

How many hours are on the engine now? Is it fully broken in?
Mine ran inconsistently during the break in, like it had a mind of its own. (I might have caused some of it, changing oil mix and jetting and stuff)

If it's ok from 3/4 to full throttle you can try to drop your needle another notch. (Raise the clip) That leans the mixture at lower speeds. If it still isn't lean enough to buzz happily you should go one step leaner on the main jet, put the clip back on a lower (richer) notch and try it. Watch out for a lean run, if you find it's running real lean shut it off and pedal home.
If your work is a far piece it might be getting hot and sagging as you get there. I don't think these engines are stable temperature-wise for continuous running, they need a cool down break sometimes.

 

[SRPM]

I have about 250_300 miles on it not sure about hours but if I had to guess I would say about 50. it's 4.4 miles to work with one big hill ( might get a pic of it up for you guys to see) steep have to pedal with engine like I said before but the rest of the trip is mostly flat and down hill

 

[SRPM]

Also I think it's more 3 stroking than 4stroking like when I let off the throttle. If I where to try to put the sound of the engine into words/letter it would be like zzzbbbbbbzzbbbbbzzzzzbbbbbbbbbbzzbbbb instead of a nice zzzzzzzzzzzzzzzzz on the throttle when ithei let off it's more like gugugug and kinda sound like bouncing a metal ball on concrete really fast.

 

[Slogger]

Hahaha
The metal ball on concrete sound is disturbing..
The "zzzbbbbbbzzbbbbbzzzzzbbbbbbbbbbzzbbbb" sounds like you could go leaner, but I hate to say that when you aren't out of the break in zone. You're almost there, but they really do seem to be inconsistent for about 300 odd miles. Mine is, anyway. As the rings seal the pump becomes more and more efficient, the running characteristics will change some.
I'd run it and read that plug, check for leaks and drag my feet on changes for another 40 miles or so.
To be safe.

 

[SRPM]

Haha the metal ball thing was just a way to explain it.will do that and keep you guys posted

 

[66cc]

https://www.youtube.com/watch?v=46Eigr5-6xY

check the fix in the description.

 

[Waxxumus]

Yay

Samuel Russell Patrick McClanahan...
You can call me Mr. RPMs

S - R - P - M
R - P - M - S?
Russell Patrick McClanahan samuel
Mr. SRPm
​

​

 

[wildone]

Step 1: remove the air filter and do test runs. I have been reading motorcycle sites and I see where several mechanics suggest just putting some type of plastic enclosure around the air intake. (So I made one of my own and my 4 stroking problems are gone!) With your engine getting a full breath of air, you will know if your mix is too rich.

The 2 stroke should run best when you find the sweet spot on the throttle intake. Sometimes, WOT is too much air and the motor will 4 stroke out. Sometimes, ou may have to throttle BACK a HAIR to get good engine advance.

Once you know you have good air, then make sure you have good fuel flow. If your line has a kink or there is fuel foaming due to vibration, your engine will not get enough gas to go up to high RPM brap state.

I like the NGK B6HS as a plug and it is plenty hot here.

when you said put a enclosed plastic around the carb!!! are you talking like a air box on a street bike that feeds the carbs??? just wondering cuz i dont see how that would stop 4 stroking.. as my understanding is 4 stroking is caused by running to rich on top end and only your jetting is gonna effectively change the problem. the best performance mod i did to mine is a dellarto clone carb ( came with new cable 5 sizes of extra jets )and a long pipe expansion chamber i got off of ebay from bicycle_motor_works.com the best advice i would give is junk the oem carb and pipe and the headaches that go with them

 

[blackfox]

I just went through trying to use the dellorto clone.
I got 6 jets that came with.

For me personally it was by far the worst mod I have tried.
It started nice and easy I like the way the choke springs back but also I never needed choke until I installed that clone.

When installed I couldn't make it up the smallest of inclines. I live in the foothills of mountain range.
I have to go up and down many slopes and steep inclines.
I removed pedals and just made a little motorcycle occ stingray chopper.

Anyhow the clone robbed all my power. It was a struggle to get up to 20 mph.
I had to walk it up the slope down my road.

So I tried all the jets the smallest one wasn't labeled. The rest of them just got bigger and did very little to change performance if any I couldn't tell.
I've read a lot about the jets that come with those clones are miss labeled and since I have read a lot of bad reviews.

I wish I could get it to work. I was under the impression that it was mostly maintenance free other than changing the jets just suppose to be install and go.

Course I researched more after the bad experience and found that not only are they not slap and goes but very tunable.

I found all kinds of slides that changed the speed of air that hits the fuel and suppose to be able to super fine tune.

However the slides are $10 and up and to many for me to want to fork out the cash and start changing all these slides while going threw all the jets on each slide and plug chopping endless lol.

I replaced the stock nt carb on and pow all my power was right back. With the nt and my chopper drag pipe I'm getting it to around 40 mph now.
Also not only do i go up all these hills but I increase speed while climbing.
There's only a few very steep inclines around here that I can't accelerate going up just at worst ever so slightly start slowing down but more just mataining a speed to the top.

I want to make the clone work so bad.
I've read a lot of people that buy the clone have their own issues and go back stock.
These people say they play with modifying the slides themselves with dremels and files and what not.

I'll probably do more research on the effects the different slides do. Find one that is suppose to do what I need and modify it myself as well.
Maybe that would make it the best mod.
That'd be pretty sweet.

I've still go plenty of mods left I can and will be doing.
I'm shooting for at least 65 mph.

Ricky Bobby I wanna go fast.......

I'm thinking about installing a walbro carb with the diaphragm no float and low, mid, high adjustment screws on it. No jets just dial it in also without that float my performance wouldn't change when riding on unlevel ground.

Has anyone here using or tried a walbro?
If so what was/is your assessment of walbro?

What model works or shall I say fits best?
I know you need a spacer I'd definitely be using a reed valve. I do know that will be needed and it has to mount far enough back so the engine heat doesn't melt or disfigure the diaphragm.

Thanks for any walbro input if you have any..

 

[Street Ryderz]

I just went through trying to use the dellorto clone.
I got 6 jets that came with.

For me personally it was by far the worst mod I have tried.
It started nice and easy I like the way the choke springs back but also I never needed choke until I installed that clone.

When installed I couldn't make it up the smallest of inclines. I live in the foothills of mountain range.
I have to go up and down many slopes and steep inclines.
I removed pedals and just made a little motorcycle occ stingray chopper.

Anyhow the clone robbed all my power. It was a struggle to get up to 20 mph.
I had to walk it up the slope down my road.

So I tried all the jets the smallest one wasn't labeled. The rest of them just got bigger and did very little to change performance if any I couldn't tell.
I've read a lot about the jets that come with those clones are miss labeled and since I have read a lot of bad reviews.

I wish I could get it to work. I was under the impression that it was mostly maintenance free other than changing the jets just suppose to be install and go.

Course I researched more after the bad experience and found that not only are they not slap and goes but very tunable.

I found all kinds of slides that changed the speed of air that hits the fuel and suppose to be able to super fine tune.

However the slides are $10 and up and to many for me to want to fork out the cash and start changing all these slides while going threw all the jets on each slide and plug chopping endless lol.

I replaced the stock nt carb on and pow all my power was right back. With the nt and my chopper drag pipe I'm getting it to around 40 mph now.
Also not only do i go up all these hills but I increase speed while climbing.
There's only a few very steep inclines around here that I can't accelerate going up just at worst ever so slightly start slowing down but more just mataining a speed to the top.

I want to make the clone work so bad.
I've read a lot of people that buy the clone have their own issues and go back stock.
These people say they play with modifying the slides themselves with dremels and files and what not.

I'll probably do more research on the effects the different slides do. Find one that is suppose to do what I need and modify it myself as well.
Maybe that would make it the best mod.
That'd be pretty sweet.

I've still go plenty of mods left I can and will be doing.
I'm shooting for at least 65 mph.

Ricky Bobby I wanna go fast.......

I'm thinking about installing a walbro carb with the diaphragm no float and low, mid, high adjustment screws on it. No jets just dial it in also without that float my performance wouldn't change when riding on unlevel ground.

Has anyone here using or tried a walbro?
If so what was/is your assessment of walbro?

What model works or shall I say fits best?
I know you need a spacer I'd definitely be using a reed valve. I do know that will be needed and it has to mount far enough back so the engine heat doesn't melt or disfigure the diaphragm.

Thanks for any walbro input if you have any..

Depending on the reed you use the walbro may not be the best idea. The walbro carbs with diaphram require the case to be tapped with a fitting for pulse line and since all there carbs are pretty small I dought the diaphram moves enough fuel to match the volume needed for the reed set up.I've seen a secondary much larger diaphram volume pump used on a case reed set up but with a standerd style carb for the air volume.