I picked up a non running kolt 90. The previous owner thought it sucked in dirt through the carb and needed a piston and ring.

When I got it home, I started some basic trouble shooting.

I checked for spark, looked fine.
I then checked compression. It seemed really low. I then put a compression tester on it and it confirmed it was low. It didn't make it above 10PSI (although I am not 100% sure of the condition the gauge).

Then I tried to start it. It took a while but it did start. It ran for about 2 minutes then died. I could not restart it (To me it seems flooded).


I know nothing about the quad or any other Chinese quad so my questions may be obvious.

Is there a special way to measure compression?
What should the compression be?

The carb looks as if it is partially open. How far open
should the slider in the carb be?

What other quad brands have interchangeable parts? It seems like a lot overlap. I was told the Polaris scrambler and the xtreme 90 are the same. Can anyone confirm this?

What are some reliable online part suppliers?


I am ready to tear into it but I do not want to pull the cylinder if it is not the issue.
I really need to get it running by Christmas.

Thanks.

 

Compression in my stock one that was about 3 years old had about 86lbs of compression on it. 10 is very low. They can run on 80 PSI but I think stock is somewhere's over 100. When you check compression keep the switch off. HOLD the throttle wide open and crank several times .. the guage will top out at its highest point.

The carb piston is barley raised at all. You cannot see through the carb with it down.

What does the spark plug look like?

I am not sure about the Alphasport.. Is it a 2 stroke ? IF its a 2 stroke most of the CVT automatics parts interchange. Eton, polaris and a ton other fit with easE

For my eton 50 I got a 70cc airsal aluminum big bore kit with polished high compression head for $200 from http://www.lakesmotorsports.com . They were great.. Head had a small nick in the head and they sent me out a new one next day. My ATV is runing great now.

 

Something must have went wrong when I checked it. If stock is 100, there is no way it would run on 10.

I went down and looked at the carb. The adjuster was turned all the way in, causing the slider to open.

Any idea what the stock carb settings are?
I tried to start it again, the plug was wet.

 

I have had my old three wheeler start and run on 60 psi then would never restart. MAke sure you have the throttle open fully when checking it.

The carb may be dirty or clogged. What about the choke?


WHat adjuster are you talking about? The one on the cable itself? Is so just loosen the cable until the slider closes all the way. Then there are 2 screws on the carb.. The one easiest to adjust is the idle screw. The other carb screw is usually recessed in the carb slightly. Thats the air/fuel.. The air fuel screw is usually 1 1/2 to 2 turn out. The idle screw I always start at about 2 turns out and work from there.

Some one may have played with the setting on the carb to get the motor up and running.. Thats what they did on my eton 70 when i got it.

Where are you located at? I doubt you are close to Maryland though

 

I am really leaning toward carb issues. It seemed to be flooded. I got it to fire again tonight. Just one time, and the plug looked wet. So, I took the carb apart. It looked clean but I am not sure about the float adjustment. The previous owner said it was spitting gas out of the carb. Are there any specs on how to adjust it? I sprayed it with carb cleaner and the bowl gasket swelled up.

I figured I could not get it running without it so I took the head off, then the cylinder and then the piston.
There is a little wear on the cylinder but no real scoring. The piston has a little wear but no obvious signs of damage. The rings look good.
How sensitive are the engines to wear? Do they have to be scratch/wear free to get compression?
Is there a way to post pictures on this site?

 

I dont know how to post pictures..

If in doubt you can get a new top end for 150-200 . That comes with cylinder, piston, rings, wrist pin and sometimes the high compression head. That will take that out of the equation and plus the engine is apart now.

I did that to our Eton and it fixed our problem. AS for it spitting out gas it could very well be the carb or choke sticking. You have to disassemble the carb and blow light air pressure thourgh the jets to get everything out. I have a Kasea 50 that has the same issue that was given to me. I havent had time to take that apart and start to fix it.. Thats on next weeks agenda.

 

It appears to have an electric choke.
What activates the choke?
If I disconnect the wires, will it be stuck on or off?
I was thinking that it may have been sticking on causing the carb to flood.

 

I have a fair amount experience with my sons Alphasport 90 but mine is the Cobra but not stock at all. Your compression needs to be over 100lbs and make sure your gauge works. You need to check out your reeds located where the carb attaches to the motor with 4 bolts. Definitely need to take your carb apart and clean it thoroughly. A top end rebuild kit is mandatory if your compression is below 100lbs. clean filters or replace them and new plug of course. I have dealt with Hetrick Racing and have most of the parts you need, they are very reliable ask for Rich, Robin or Chris.

 

I ordered a gasket set and rings. I am throwing in rings just because it is apart. I am also going to try and get it honed.
It had to be the gauge that was off. With no parts damaged and no visible signs of wear, there had to be compression. Not to mention, it did run twice for a minute or two.

I took the reeds out last night. They looked okay.

Any idea where I can find torque specs?
Or specs on how to adjust the float?

 

If i can remember since I did it about a month ago is the head torque is 14 or 16lbs. Sorry i can not help with the float because I have never touched mine since it was brand new aftermarket ugraded kehin 20mm from Hetrickracing. If you've searched here, try google for float adjustment. Im sure you willl find what you need. Good luck