90 Marathon 2 Stroke

[brownchristian]

Just picked up a 90 marathon 2 stroke which was my wife's grandfathers. He passed away a few years ago and this has been sitting since. Took it to a repair shop and $400 later they replaced the coil, ignitor and gave her a tune up. They called and told me I needed a new carb and it would be another $200 plus. I decided against the carb since I figured all it needed was a cleaning. They had it running but you had to play with the choke to keep it running. Took it out this weekend and after 30 minutes or so I couldn't get it running anymore. Took the carb out today and cleaned it up. Removed all the jets sprayed them out with carb cleaner and put back together. Put it back together and after a couple shots of ether she started. Now she runs great but still better with about 1/4 choke so I adjusted the choke cable to 1/4 choke. Is this a proper setting or am I just making a temporary fix?

[brownchristian]

2nd question:

Like I said previously the cart runs great when it is running. I actually think it may go too fast but I can deal with that . After about 10 minutes of running the engine will slow down and start to die. If I pull the choke out it will rev up again and if I keep it pulled it will keep going. If I stop and then start again it runs fine again. What could be causing this?

[brownchristian]

3rd question:

The only thing I see wrong with the carb is it seems to be missing a bushing or something on the throttle butterfly assembly. There is some lateral play in the butterfly but it doesn't seem to effect the rotation of the butterfly. Could this be causing a problem?

[brownchristian]

Last Question:

Here is a pic of my carb. Is there something missing in that hole on the left of the carb or should I just put a bolt in there? Is this causing any issues?

[brownchristian]

Finally here is a pic of the cart. Not bad shape for a 19 year old cart.

[divot61]

sounds like your getting to much air in the carb from the sloppy butterfly, this will indeed mess up the fuel air ratio, visit the sponsers of the site and they may have something a little cheaper than 2 bills for a carb, or someone may have an extra carb laying around

[brownchristian]

Originally Posted by divot61

sounds like your getting to much air in the carb from the sloppy butterfly, this will indeed mess up the fuel air ratio, visit the sponsers of the site and they may have something a little cheaper than 2 bills for a carb, or someone may have an extra carb laying around

Thanks divot61 for the response. I have actually found a carb for less than $100 online. Just don't want to spend the money unless it is 100% necessary. The butterfly closes all the way but I am sure the shaking around while driving could be moving it slightly to allow more air.

[divot61]

if indeed the hole that you have shown us does pull air when you start it, it WILL mess with the ratio.
put the cart in neutral and fire it up, place your finger over the hole while its running and see if it makes a difference, if so i think it my be some kind of cover for the throttle linkage, so nobody messes with the governer. just plug it and you should be ok

[shawn.m]

the hole needs a bolt. that is where the oil injection tube went. I hope you are running pre mix in the tank or you are going to burn up the motor.
and yes if you have that hole open you will have to run the choke 1/4 open all the time.

didnt the shop tell you about this? Did they point out that you were missing the oil injection hose and linkage?

[brownchristian]

Originally Posted by shawn.m

the hole needs a bolt. that is where the oil injection tube went. I hope you are running pre mix in the tank or you are going to burn up the motor.
and yes if you have that hole open you will have to run the choke 1/4 open all the time.

didnt the shop tell you about this? Did they point out that you were missing the oil injection hose and linkage?

Thanks Shawn. I fugured this needed a bolt and yes I am running a premix in the tank.