BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum

Go Back   BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum > Technical Discussions > 150cc GY6 and Under Engine Tech

150cc GY6 and Under Engine Tech GY6 and Smaller Technical Discussion Forum

Reply
 
Thread Tools
  #1  
Old 12-22-2014, 09:43 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default Need some help again

So I replaced the carb on my 110cc buggy with a pz20. The old carb had some physical damage and was leaking. But when it felt like it it would run great, lots of low end power. Now with my new carb, I think Iam running rich because I can't use the choke otherwise it will die and it bogs really bad on take off. Like it won't start moving if it's on a paved hill nothing to steep like 6%. But once it gets moving it runs great. If i am correct and it is rich what do I adjust. Replacing the main jet with something bigger would effect the top end where it rrunning good right? I have tried going up and down on the needle clip without being able to get rid of the problem. The carb is new and I cleaned it. I am a lose as what I should do.
Reply With Quote
  #2  
Old 12-23-2014, 03:06 AM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

The first step in carb tuning is taking note of all the current settings: fuel screw setting, float level, pilot jet, main jet, needle jet, clip position, and possibly more depending on the carb. This way, if tuning makes it worse, you can at least get it back to where it was. The main jet controls the the top end, so you are right in thinking you shouldn't change it(for now). After documenting the current settings, the first thing I would do is adjust the fuel screw for the optimum idle. This setting will tell you what direction you need to go with your pilot jet.
Reply With Quote
  #3  
Old 12-23-2014, 04:42 AM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

I have adjusted the fuel screw in every possible setting. I think i am still running rich, because if I try and touch the choke it does. So if I return everything back to how I got it and still can't adjust the fuel screw to a point where I get rid of the bog/hesitation what do I do? Also i read tthat tuning the carb has nothing to do with rpm or top or bottom end but solely on throttle position it doesn't matter it i am running good when Iam going fast, it's still just as rich as when I am trying to accerlate from a dead top. Or am I completely miss understanding this.
Reply With Quote
  #4  
Old 12-23-2014, 06:37 AM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

What carb was originally on the engine, are you blowing black smoke, what does the plug show you, and last what color is your spark.
Reply With Quote
  #5  
Old 12-23-2014, 10:19 AM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

I'm sorry, my wording was not the best for someone that is learning. The main jet controls the fuel flow at wide open throttle. The fuel screw should be set to where it gives you the highest idle rpm (while the engine is at operating temperature). This setting should ideally be somewhere between 1-2 turns out from lightly seated. If it is less, the pilot jet is too large. If it is more, the pilot jet is too small.
I would warm the engine up and take note of the stock fuel screw position. You do this by turning the fuel screw in until it just stops, counting the turns it takes to get there. Do not put any torque on it or the screw or carb could be damaged.
Next set the fuel screw at 1.5 turns out from lightly seated and adjust the idle to the proper setting. Then slowly turn the fuel screw in or out until the idle rises to the highest rpm. once you have reached the highest rpm, adjust the idle back to the proper setting. This should be the optimum fuel screw setting.
Next count the number of turns the fuel screw is backed out. Like stated above, less than one=get a smaller pilot jet, more than 2=get a larger pilot jet. If it is between 1 and 2 turns out, your pilot jet should be fine.
The questions asked by sycarms are important. Trying to tune the carburetor of an engine that is not in good mechanical condition is useless. You will need good compression, good spark, clean air filter, valves adjusted properly, fresh fuel, etc. etc.
what do you mean "when you try to touch the choke, it dies"? Choke it, and it dies? Or turn choke off, and it dies?

Last edited by 351mustanger; 12-23-2014 at 10:24 AM.
Reply With Quote
  #6  
Old 12-23-2014, 02:14 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Here's a picture of the plug. Looks a little rich, but to me not overly bad.
Reply With Quote
  #7  
Old 12-23-2014, 02:17 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Here maybe this will work for the picture
Attached Images
File Type: jpg 1419365621965.jpg (94.5 KB, 8 views)
Reply With Quote
  #8  
Old 12-23-2014, 02:19 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

It doesn't ever need the choke to start, and if i turn it on when at any time it causes the motor to die.
Reply With Quote
  #9  
Old 12-23-2014, 02:44 PM
liduno liduno is offline
Heavy Contributor
 

Join Date: Aug 2014
Posts: 702
Default

I aint helpin till you tells us how you got the chain problem worked out..lol
Reply With Quote
  #10  
Old 12-23-2014, 02:56 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

? Well there was some grinding from the owner before where it was rubbing. So right or wrong I adjusted the chain tighter than it should be so the chain was barely rubbing, hoping that it would stretch since it was a new chain. Drove it for a more or so, gunning it and stopping. And the chain did stretch just enough so I could adjust everything to the right tension and it wasn't rubbing. It's real close but not touching.
Reply With Quote
  #11  
Old 12-23-2014, 03:09 PM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

If it doesn't need the choke to start, then the idle circuit is rich or the float level is set too high, assuming there are no mechanical issues.
Reply With Quote
  #12  
Old 12-23-2014, 03:14 PM
liduno liduno is offline
Heavy Contributor
 

Join Date: Aug 2014
Posts: 702
Default

Quote:
Originally Posted by Dieselpusher6262 View Post
? Well there was some grinding from the owner before where it was rubbing. So right or wrong I adjusted the chain tighter than it should be so the chain was barely rubbing, hoping that it would stretch since it was a new chain. Drove it for a more or so, gunning it and stopping. And the chain did stretch just enough so I could adjust everything to the right tension and it wasn't rubbing. It's real close but not touching.
Glad you got it worked out but I must admit that I lied..lol I have nothing to add to this thread, the advice you've already received is sound advice.

Last edited by liduno; 12-23-2014 at 03:31 PM.
Reply With Quote
  #13  
Old 12-23-2014, 03:53 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Adjusted as suggested above. Air fuel screw is aadjusted out 1 and 1/3 out. Idle speed is out 1 1/4. Here's a pic of the plug. I ran it up and down the street wide open, turned the kill switch off and coasted to stop. Not sure if you can see in the picture but the plug looks pretty good to me. A nice dark tan/coffee with a touch of milk color. No wetness. Gaint stumble from take off with alot of tthrottl. Ease into it and and about 10 mp3 it starts pulling bette, can floor it from there and runs great to top speed. Would the float cause a stumble like that, iI thought if it was out of adjustment it would run out of gas on the top end when it's using the most gas, it seems like even a small amount of gas in the bowl would be enough to take off. The clip on tthe needle jet is one position higher (so the needle sits lower tried the other way and still had the same problem.). I haven't checked the Compression yet because I tester iI have doesn't fit in the spark plug hole. I guess I have to figure out an adapter. Anyways just so I am clear the hesitation is caused by to much fuel right? Should I try the clip in the last position dropping the needle as far as it goes? I also have the black slide the needle sits in that's is stamped 35, the one that came with it says 40. What do those numbers mean, and should I switch them around?
Attached Images
File Type: jpg 1419370349438.jpg (99.1 KB, 4 views)
Reply With Quote
  #14  
Old 12-23-2014, 04:11 PM
liduno liduno is offline
Heavy Contributor
 

Join Date: Aug 2014
Posts: 702
Default

Google ''jetting chart''
Reply With Quote
  #15  
Old 12-23-2014, 04:12 PM
liduno liduno is offline
Heavy Contributor
 

Join Date: Aug 2014
Posts: 702
Default

And a float level that's too high is just 1 thing that can cause a bog.
Reply With Quote
  #16  
Old 12-23-2014, 05:16 PM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

Usually a lean condition causes a stumble. Raising the clip on the needle leans the mixture. Lowering will richen it. A float level adjustment will effect jetting from idle to wide open throttle. A larger float level measurement will lean it out and a smaller float level measurement will richen it. Do you know what carb you have? Or maybe a pic of it would help.
Reply With Quote
  #17  
Old 12-23-2014, 05:17 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Not to sound like an ass, but before taking the time to write out as much as I have so far, I most likely would have Googled jetting, hesitating at idle, bogging, carburetor tuning, 110cc carburetor problems, and every possible combination of those words possible. From the advice given so far getting the mixture screw set was the first step. And that is why I have turned to the forum for help because if I Googled jetting chart and followed it, but my setting for the mixture where the problem then I would be swapping jets, and ordering parts when that wasn't the problem. And you said the float height can cause the bog. I considered that and is why asked for an explanation, and gave my thoughts. Not mention the needle position can be effecting everything and the slide the needle sits in. So since I am past what I know to do I thought to ask for help, and being told to google jetting chart doesn't help if one of numerous other things is causing my problem. No top of, my plug looks good which as I understand it means my jetting is good or at least close. On the other hand I wanted to say thank you to the people that have taken the time and effort to write out there suggestions. Because of them I feel up to this point I am doing what I should, instead of just turning screws and hoping for the best
Reply With Quote
  #18  
Old 12-23-2014, 05:24 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Pz20 or a generic version of it. Here's a link to it http://m.ebay.com/itm/371174737752?_mwBanner=1

If a picture would help let me know, but that is the exact carb that's a couple days old. Does anybody know what the float height should be.
Reply With Quote
  #19  
Old 12-23-2014, 06:32 PM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

Usually the numbers on the slide denote the throttle cutaway. I have personally never tried swapping them, so I have no insight on the changes it would make. That carb is a copy of a mikuni vm. I don't believe the float level is adjustable on the smaller ones. The float and adjustment tang are one piece and plastic. There is a free vm tuning manual floating around online. Just google mikuni vm tuning. It is specific to your carb type.
Reply With Quote
  #20  
Old 12-23-2014, 07:13 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

351mustanger if the hesitation is caused by a lean condition, wouldn't choking it a little help the problem. Because you would be cutting of the amount of are and in turn richening the mixture. Where if I apply any choke it dies. And please don't think I am being argumentative, just trying to get a better understanding. And i am greatly appreciative of all the help. Oh my jetting is 89 main and can't find the number on the other jet
Reply With Quote
  #21  
Old 12-23-2014, 07:58 PM
351mustanger 351mustanger is offline
Contributor
 

Join Date: Jul 2013
Location: Cincinnati, Ohio
Posts: 160
Default

Usually when jetted too rich, it will have a bit of a gurgley sound and smoke from the exhaust at certain throttle positions. You could have someone watch as you drive it to see if it blows a puff of smoke durring the bog. I would bet it is a lean spot though. I would try lowering the clip to see if it gets any better. Check out the pdf manual I mentioned. It will educate you to make the best guesses on jetting. Without being able to drive it or hear it run, it is hard to say for sure what circuit needs attention. Also check to make sure you have no air leaks between the carburetor and cylinder head. If any of the gaskets or o-rings are not completely sealed, air can be drawn in and cause a lean condition. You can spray a little starting fluid around the areas and see if the rpm changes.
Reply With Quote
  #22  
Old 12-23-2014, 10:56 PM
liduno liduno is offline
Heavy Contributor
 

Join Date: Aug 2014
Posts: 702
Default

Quote:
Originally Posted by Dieselpusher6262 View Post
Not to sound like an ass, but before taking the time to write out as much as I have so far, I most likely would have Googled jetting, hesitating at idle, bogging, carburetor tuning, 110cc carburetor problems, and every possible combination of those words possible. From the advice given so far getting the mixture screw set was the first step. And that is why I have turned to the forum for help because if I Googled jetting chart and followed it, but my setting for the mixture where the problem then I would be swapping jets, and ordering parts when that wasn't the problem. And you said the float height can cause the bog. I considered that and is why asked for an explanation, and gave my thoughts. Not mention the needle position can be effecting everything and the slide the needle sits in. So since I am past what I know to do I thought to ask for help, and being told to google jetting chart doesn't help if one of numerous other things is causing my problem. No top of, my plug looks good which as I understand it means my jetting is good or at least close. On the other hand I wanted to say thank you to the people that have taken the time and effort to write out there suggestions. Because of them I feel up to this point I am doing what I should, instead of just turning screws and hoping for the best


Just to be clear, I would have no way to know that you already googled a jetting chart.

To be fair, if you had googled a jetting chart, you should know what changes effect what throttle position.

The questions you were asking lead me to believe you had not googled a jetting chart.

Me explaining what changes effect what throttle position would take pages of text, a chart explains it at a glance.

So forgive me for suggesting you google a jetting chart. I'll not bother you with my asinine suggestions again.
Reply With Quote
  #23  
Old 12-24-2014, 10:42 AM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Ok so what u think my next step is a buy a new lidle jet. I have adjusted the mixture screw as suggested. Adjusted the float, recleaned the carb and have tried the needle position in all positions and still have the same problem. I also realized that if you give it just a little bit of throttle it starts to Crap out. And just continuing to hold that part tthrottle is just keeps cropping out. I never just held the throttle in that position before because I was aalways trying to take off. Does that all sound about right, me needing a richer needle jet?
Reply With Quote
  #24  
Old 12-24-2014, 12:20 PM
SYCARMS's Avatar
SYCARMS SYCARMS is offline
Supporting Vendor
 

Join Date: Sep 2009
Location: Senatobia, Mississippi
Posts: 3,375
Default

I'll ask again was the old carb a PZ20 or smaller? Both plugs in your pics are very rich.
Reply With Quote
  #25  
Old 12-24-2014, 01:27 PM
xlint89's Avatar
xlint89 xlint89 is offline
Senior Member
 

Join Date: Dec 2011
Location: cleveland OH
Posts: 1,064
Default

I'm curious to see why you replaced the carb as opposed to cleaning/rebuilding the stock one?
__________________
My Yerban assault vehicle: 2.2mm stroker crank, 62mm Nikasil cyl, Taida large vavle head, American made valve springs, ported intake manifold, TM 28mm carb, stock CDI, Bando coil, TK exhaust, stock CVT except for the 14g sliders, 13/40 internal gears, 16T drive, 31T axle sprocket, 22" rear tires, and ONE BIG POTATO CANNON mounted on top..........
Reply With Quote
  #26  
Old 12-24-2014, 01:53 PM
Dieselpusher6262 Dieselpusher6262 is offline
Lite Contributor
 

Join Date: Nov 2014
Posts: 31
Default

Quote:
Originally Posted by Dieselpusher6262 View Post
So I replaced the carb on my 110cc buggy with a pz20. The old carb had some physical damage and was leaking. But when it felt like it it would run great, lots of low end power. Now with my new carb, I think Iam running rich because I can't use the choke otherwise it will die and it bogs really bad on take off. Like it won't start moving if it's on a paved hill nothing to steep like 6%. But once it gets moving it runs great. If i am correct and it is rich what do I adjust. Replacing the main jet with something bigger would effect the top end where it rrunning good right? I have tried going up and down on the needle clip without being able to get rid of the problem. The carb is new and I cleaned it. I am a lose as what I should do.
Ordinary one was physically damaged.
Reply With Quote
  #27  
Old 12-24-2014, 02:41 PM
x-bird's Avatar
x-bird x-bird is offline
Power User
 

Join Date: Oct 2011
Location: Penciltucky
Posts: 2,518
Default

does this little thing have a pilot jet circuit?
idle/part throttle is showing rich because of the sootiness/blackness of the base ring of the plug. The rest of the rpm range looks rich too. I think you're too rich at idle/part throttle. Either lower the needle, adjust the float, or consider a smaller pilot jet if there is one and the two previous items don't help the situation.
Reply With Quote
  #28  
Old 12-24-2014, 10:41 PM
Miamieddie's Avatar
Miamieddie Miamieddie is offline
Heavy Contributor
 

Join Date: Jan 2012
Location: miami. florida
Posts: 610
Default hmmm!!!

I wonder if your sparkplug wire is bad? A bad wire can make it seem like bad tunning. Just saying.
__________________
2. 150cc carters. 1. Baja reaction 150cc dr2 variators Jerseydevil hp. Pipes unifilters gates belts. Yellow main springs hd. Orange coils.
Reply With Quote
  #29  
Old 12-24-2014, 10:43 PM
Miamieddie's Avatar
Miamieddie Miamieddie is offline
Heavy Contributor
 

Join Date: Jan 2012
Location: miami. florida
Posts: 610
Default

It happened to me. Not saying this is the case here. But just never know.
__________________
2. 150cc carters. 1. Baja reaction 150cc dr2 variators Jerseydevil hp. Pipes unifilters gates belts. Yellow main springs hd. Orange coils.
Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 05:34 PM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.