Help!! Low power on and can't figure out why - BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum

jpcjguy · #1 07-22-2018, 04:39 PM

Hi all,

So I picked up a kandi 150 gka-2. Here is a stock pic:

It was smoking real bad when I got it and I put a new big bore kit to 155cc. This is the one I got: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This was my first time working on one of these and I got it running. I put a 120 jet in the carb. My problem is low power. Going up a mild hill on the street and I can only go about 13 mph.
I had an intake leak and ordered a new one. This one here: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

What else can I check? How do I diagnose this from here? Could I have the timing wrong? I double checked the valves and set them at .005. I did a compression test and got 185-190 psi.

I took the carb apart again and checked all the jet passageways. appears to be getting fuel - when I take the line off the carb, fuel dumps out....

Oh - I also went to a yellow spring and 10g roller weights (did this last year so going on memory on the roller weights! 99%)

The spring I bought: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thanks!
Joe

plee911 · #2 07-22-2018, 06:10 PM

What jet was in the carb before the big bore. Have you checked your plug what does it look
like. Is it bogging during the climb or just no speed.. How does it run on flat ground.

plee911 · #3 07-22-2018, 06:19 PM

I'm thinking you may have gone way to big on the jet depending on what was in there stock. If all you did was a big bore 155cc but didn't open up the intake and exhaust then your jet size wouldn't change very much if at all. If it's not getting up to speed even on flat ground then could be your rollers. Check them for flat spots and 10 g rollers may be too light. Get back to us with more info and we can help you sort it out.

jpcjguy · #4 07-22-2018, 07:46 PM

Thanks for all the suggestions. I have a Uni filter setup - but I have been testing with nothing on the carb currently.
Unfortunately, I don't remember what the stock jet was. I did this over the winter and just coming back to the buggy. Exhaust is stock muffler.
Flat ground is a little faster, have not had time to do a bunch of test runs. Just feels like no power - especially compared to my Baja Dune 150 (which is a lighter/smaller buggy)

I will do some more testing in the next day or two, starting a new contract job tomorrow, and will report back. I will clean up the plug and then do testing and see what it looks like.

neo71665 · #5 07-22-2018, 09:24 PM

There isn't any size XXX jet goes with XXXX upgrade. You need to read the plug and adjust accordingly. On these engines the small amount of extra air it gets from no filter will change the required jetting from running it with a filter. Small engines are more picky and respond in more drastic measures than say a v8.

Best bet is to park it and order the jet kit for one of these so you have them on hand to tune with. You can pick up a kit on ebay for around $10 now. It will seem like a waste to have the extra 9 jets sitting there once you get it tuned but it saves a ton of headaches than just ordering one at a time and waiting for shipping.

plee911 · #6 07-22-2018, 10:14 PM

Here is the Jet kit. It comes on the slow boat from china. Or you can order from in the states and it will be here fast but cost more.
One thing to keep in mind the supporting vendors are in state and will make sure you get the right parts or make it right ever time.
The same cant be said for china stuff.
https://www.ebay.com/itm/10Pcs-Carbu...53.m2749.l2649

What are your RPMs doing are they high or is the engine bogging?

NEO is right that you wont be able to get a good read without your intake on.

Im no expert by any means but it seems that a lot of the newer buggies were sent out with smaller jets 112 and 114 I think I even remember seeing a few posts with ones that had a 108 main.

A 120 with a UNI mod is an OK place to start but its only that a starting place. You have to read the plug and adjust the jets to get where you are supposed to be.

How did the buggy run before the upgrade other than the smoking?
Is it reaching high RPM quickly or is it taking a while to get there?

If its hitting high RPM but your not getting speed then its probably not your jets

If its boggy and slow to climb to higher RPMs then jets are a good possibility but not the only one.

Spray some carb cleaner around your intake if it falters then you have an intake leak.
I know you just bought a new one but even new ones can leak.

If its reaching high RPMs quickly

You may also pull your CVT cover and see if you belt is traveling up and down on both pulleys like it is supposed to. If its not that could also be the cause of you low power.

Even if one of these is what's causing your issue you still really need to get the jetting correct. Rich will foul your plug. Too rich will diesel and wash your cylinder walls and you will end up with gas in your oil and damage to your cylinder and piston. Too lean and you will fry your rings.

Get back to us with what you find out
I will throw out suggestions but remember im not an expert just trying to help

NEO and others on here are experts and give great advise they really know their stuff but the more info you can give about the symptoms and what the motor does the faster they will be able to help you sort out the problem.

The main goal is to get you out riding and enjoying your buggy again.

jpcjguy · #7 07-23-2018, 01:10 PM

thanks Plee911 - lots of great info that I will report back on. I did take this video yesterday. Hope the link works ok:

https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

plee911 · #8 07-23-2018, 06:18 PM

Ok watching the vid I see the belt climbing all the way on the variator. The clutch however never moves above half way. That would affect your gearing. Also from listening to the motor it sounds to me like your idle is very high and you have some cut out at the higher speeds. Did you adjust your air fuel screw at all after the rebuild? The high idle could be why your clutch isn't closing like it should which would cause it to be a dog off the line and take a long time to accelerate you also would have no power when trying to climb a hill. Will let some of the guys listen and watch the vid and see if they are thinking the same way.

Edited to be more clear about what im seeing and hearing.

**JERSEYDEVIL** · #9 07-23-2018, 09:55 PM

check the vari for sideways rollers

jpcjguy · #10 07-24-2018, 10:17 AM

At the time of the video, the idle was high - battling intake manifold leaks. Bought a new one but think it is suspect also.
I will check the rollers also. The variator is new and so are the rollers.

**JERSEYDEVIL** · #11 07-24-2018, 03:48 PM

does the motor run smooth?
is the idle erratic (up and down)

**SYCARMS** · #12 07-24-2018, 04:12 PM

From watching your video you are stuck on high gear. Even at that high idle the belt should be just about at top of clutch pulley. When you throttled up you could see a point in which the belt had quite bit of slack in it and when you let off throttle the belt was not returning to the rest position. At idle the belt should be at bottom of variator and at top of clutch pulleys. As you accelerate the first thing to occur is the clutch engages than the belt movement will occur. Check the CVT for bad or improperly positioned rollers and check that the clutch pulley is not binding and returns to its full closed position.

jpcjguy · #13 07-24-2018, 07:50 PM

So I took it all apart and here are some pics of the rollers. They are 10g.

The variator and rollers are new. Put them in the winter and there is maybe 8 minutes of run time - 90% driveway testing.

jpcjguy · #14 07-24-2018, 07:52 PM

Here are some pics of the belt on the variator and the belt part number.

jpcjguy · #15 07-24-2018, 07:55 PM

Here is a link to the belt slack:
https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

jpcjguy · #16 07-24-2018, 07:59 PM

Another video

https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

jpcjguy · #17 07-24-2018, 08:05 PM

I did pick up one of those DTI TECH-TACH TT-20K Tachometer. Do I set it at 360 or 180 degrees for the GY6 engine? I think 180 because it fires on every up stroke correct? One spark is wasted on the exhaust - keeps it simple because they are using a magneto ignition that is driven directly off of the crankshaft. It is just the simplest way to get the job done. Right?

One thing that drives me crazy is that trying to set the idle is almost impossible. I go from too fast to lugging with maybe a 1/32 turn of the screw. Why is it so sensitive?

**SYCARMS** · #18 07-24-2018, 08:25 PM

Again looking at your last 2 video's the slack is too much in the belt and looking at the other video the belt never returns to top of clutch pully which is keeping you in a higher gear ratio. As I said earlier the belt on variator should be at bottom which it appears to be but the clutch pully the belt is looks like 1/2" or so down and should be at top. That clutch pully may be not all the way closed in the rest position. When installing the belt it should be at the very top of pully to where you have to work over crank and roll it on to the bushing as you turn engine by hand. Looking at the inner side of the clutch pully both halves should be touching to make a perfect v if not then you will need to disassemble the pully halves to find what is keeping it from fully closing. If you have any doubt or don't get what I'm saying give me a call 662-301-1563. If I don't pick up make sure you leave a message and I'll get right back to you.

**JERSEYDEVIL** · #19 07-24-2018, 09:29 PM

i just watch the vid, didnt see it before is that belt too long? i dont recognize the pl 20707
743-20-30 is the size
the first # is the length the second the width , both in mm the 30 is the angle of the wedge

**JERSEYDEVIL** · #20 07-24-2018, 09:32 PM

i just googled it it is the right size.

**JERSEYDEVIL** · #21 07-24-2018, 09:36 PM

something's up with that clutch?

plee911 · #22 07-25-2018, 12:51 AM

You have multiple problems that are all contributing to your issue of no power.
I recommend picking 1 and sorting it out before moving on to the next.

Start with that clutch.
The pulleys are not closing correctly. Pull it apart and find out why.

Then you got to sort out your engine

So far you have done the 155 BBK and the uni filter with the redneck intake and put in a 120 jet with out knowing what the size of the original jet was and you have intake leaks to add to the gremlins lol

Trust me when I say it would be a miracle if your mix isn't way off. (hopefully your running a bit rich but with the intake leaks your probably lean)

If you have not done it get the intake leaks fixed.
If not then you will never get it to idle properly and you can not get a proper reading of your plug until it is fixed.

Then you can look at your jet sizing to get it to where it needs to be.

All of us will help you get your buggy back to where it needs to be but there isn't going to be a magic bullet for the issues your having we are going to have to fix it 1 problem at a time.

jpcjguy · #23 07-25-2018, 06:52 AM

Thanks to Sycarms for his time last night on the phone! Great information from a really nice guy!

I looked around and found the original jet and it was a 103 - with the small chance it was a 108.

Had a few minutes this morning. Here is a video of when I took the variator "front" off.
Shows the amount of play

https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

When I took the belt off, the clutch part came together fine. I was able to squeeze it and let it go and it went right back together.

https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

I did notice some rough "patches" on the clutch pulley. I wonder if the belt was hanging up on that? Here is a video you can just see a little of it:

https://photos.google.com/share/AF1Q...tHMXVyWkpYVS1R

Also, I was wondering - could I have the belt on backwards? Would that affect anything?

OLDKID · #24 07-25-2018, 09:12 AM

An A Symmetric belt ( flat on one side , bevel on other ) only works if installed properly . Flat side inboard , corresponding with variator / clutch . Flat face inner halve / beveled outer half . 10/4 ?

**SYCARMS** · #25 07-25-2018, 11:31 AM

Watching your video it seems as if it took no effort to expand the clutch pulley. Any one I have done I could barely move it. It seems the spring is too weak. Can someone else chime in on this.

jpcjguy · #26 07-26-2018, 07:05 AM

I did have to squeeze it hard. I am not saying I am a worlds' strongest man competitor but I think I am stronger than average.

Any way I can check it if it is bad? The spring is brand new.
How about the smoothness of the pulley surfaces? Could it be hanging up on the rust spots?

**JERSEYDEVIL** · #27 07-26-2018, 12:37 PM

i dont know but by now i wouldve slapped a different clutch on it to see.

**SYCARMS** · #28 07-28-2018, 06:27 PM

With the belt on is the clutch pulley fully closed? I still watch the video and it sure seems it opens too easily. I just tried on my blade with a yellow spring and I could not open the pulley even half way using 4 fingers on each hand and you cannot without rotating the outer pulley while pulling. I think you need to remove clutch from pulley and disassemble the pulley to make sure those pins are in the pulley.