I picked up a monsoon 90cc for $30 tonight. However it is missing two key parts. Spark plug and coil. I have searched all over the net for which plug to get. I can't find a part number anywhere. Anyone have any idea. Is a 2 stroke. I have found the coil, but before I order it, I am going to try an extra that's fits my oldest sons 110 taotao. I am also thinking of buying a new carb if I can find one. Doubtful they are as cheap as the 110 taotao, which we just buy a new one every year. For 30 bucks, it is not worth cleaning them. but I really need to know which one. Hate to punch a hole in the piston. Thanks for any help

 

I purchased a coil and a spark plug. Have great spark. Compression at a consistent 120. So thought it was fuel related. Purchased new carb. No difference. Can put a little gas in carb and the thing will fire right up and run for about one second after you take finger off start button. it will continue to pop until all gas is gone if you hold the start button down. Which it seems like fuel still I have disconnected exhaust thinking it was plugged. Any ideas. 2 stroke jog style engine on the 90cc monsoon.

 

If you got spark and a new carb but it still isn't getting fuel then I would look at the fuel lines, filter see if they are plugged.

Does the carb have a bowl drain screw? If so open it up see if you get fuel to the carb.

You may have a gasket leak somewhere and there isn't enough air being pulled through the carb.

Is the engine reed inducted? If so perhaps the reeds are not sealing.

 

Yep forgot about that, installed new filter and lines before I even tried firing it up. The drain on the carb let's gas out full stream. I will try and pull the manifold boot off tonight and see if it has any cracks I can see. I'm not much of a 2 stroke guy. So the reeds are uncharted territory for me. I'm assuming this thing has reeds. If I pull them, do they have to be replaced or can they be cleaned up. I found some for a yamaha jog for $15 for a pair. I need to see if they would work before I buy them. But first I will look for leaks tonight. Just so frustrating. Has anybody ever coated a rubber intake manifold with rtv gasket maker? I looked for a new one while ordering the carb but no luck. Just want to see if it would seal up any dry cracking it may have.

 

Havn't tried using rtv but I know liquid electrical tape when left to prperly cure will dry hard as rubber. I have used it to modify intakes on 2 stroke engines before.

You can check for leaks with a can of ether. Turn the engine over and spray around the intake etc, if it fires up then you gots a leak. You may not have reeds, some engines are piston ported and don't have reeds. You will more than likely have to replace the reeds if you find they are bad.

I would also do a compression check. Pull the plug and at the very least put your thumb over the hole and see if you have compression.

 

Thanks for the tip on the liquid tape. I did a compression test while electric cranking the motor over and it read 120 consistently. I tested it several times with 1 minute between. Just in case. I used a rubber tip tester. Are those accurate enough or should I invest in a thread in comp tester?

 

More than enough for what your doing. If you get 120psi its good.

Just wanted to make sure your have enough compression to suck the air into the engine.

When you do the ther test do the case and shaft seals as well, the case (jug) has to have no leaks as well.

 

Ok pulled manifold and it all looks tip top. I do have reeds. They are stainless. They look clean but could not get the cage out. I was scared is break it. It was stuck pretty well. Any tricks to bust it loose? I was goona try Nd slide a screwdriver under it but figured I would ask here first. Also, I will Google how to test the seals you mention, unless you have an easy way. Thanks for your time and I will let you know what I come up with

 

Athena Upgrade 4 Reed Valve Bolt Removal.AVI - YouTube
This is just like my intake and reeds.

 

You can try the ether trick on them as well.

Slide a box knife in beteen the reed block and the case it should break free with a little prying.

Use some permatex motoseal and fresh gaskets when you assemble it back up.

Probably going to have to cut your own gaskets as well.