Hello,
Got a 98 blaster. Ran decent. Didnt like to idle much. I pulled the carb off and cleaned it and put on new reeds, intake boot, intake boot gasket. Thing started on the second kick and didnt need hardly any choke. This was a big improvement. Then after idling for a few minutes i started hearing a buzzing/rattling noise. I gave it a bit of gas and it died. I tried to restart it. It backfired a bit while trying to kick it up. NOw it wont start. I pulled the plug. Its a bit cruddy, but i can see it spark when i kick it. Any ideas what I should do next? Thanks.

 

Just some ideas, but this might help.... Start with the Gas Tank. Empty it, clean it, make sure the petcock is good (flow is good, strainer clean), then re-clean the carb, If you do not have compressed air, it probably aint clean. Even if you do have compressed air, could be a clogged artery.... heart stops. Next, go back to your new reeds and check them for cracks and/or damage. It is possible that you installed cracked ones without knowing,.... or they just came apart..... never know, but don't assume that they are new and can't be the problem. If you are getting spark and fuel to the cylinder, the last thing to check thoroughly, is the air intake,... filter,... that stuff. Make sure your spark plug is the correct one too. Might be too short or something that's not terribly apparent....

From your description of existing circumstances, you're missing either fuel or air,.... or even both. If the pug is still sparking you have fire, so it has to be one of the other two.... most likely fuel.

That "buzzing noise" doesn't compute anywhere but the reeds to me..... I could be missing something though

 

Thanks for the reply Terrellster. I have real good gas flow through the petcock. Gas is new. I pulled the carb again and cleaned the idle and main jets real good. I pulled of the reed valve assembly and checked the reeds, seem fine to me. No gaps or cracks that I noticed. Tried a new plug from a yamaha dealer. Wicked backfire, no starting or even close. So, I did a compression test. Pulled the plug put in the tester and kicked it about 10 times. Got about 40 psi I tightend the tester and tried again with the same results. What should my next step be.

Thanks,
dib

 

Has a brand new K&N air filter btw.

 

Not being in close proximity to my aftermarket manual, I don't know what the compression ought to be, but that doesn't sound good. Th buzzing noise is what bothers me most. Maybe a blown head gasket buzzing before tanking? Don;t know wher toi send you just yet.... Fire air and fuel are the right items, and sounds like you have them all.... Is your spark a Bright Blue spark? are a tiny blue spark or an orangy color? That spark needs to be pretty hard blue. I usually shoot a spark from a test piece to ground instead of using a spark plug and see how large a gap it can jump.

 

the spark was orange until i changed the spark plug. now it makes a small blue spark. I think i read my compression should be closer to...120psi. How could I test for a blown head gasket? Thanks

 

Put the plug back in and kick it a few times and listen for the hiss aorund the head/cylinder seem. If it's leaking off that much pressure that fast, you should be able to hear the leak. Same thing I'm dealing with on a chinese motor at work. The reason the head gasket blew on it, was the valves were not openeing enough and the compression went way up. The 2 stroke should work that way, but the hiss should be there. Get a freind to run through the kick for you so you can get down and feel around the head gasket seam too.

Typically you should be able to feel if your compression is that low. When you roll through the kick start, you should feel a hard spot every stroke, where the pressure rises on compression. Granted it may take a couple of kicks to reach that spot, but I think the gearing on the kick starter is such that you get close to once each kick running through slowly.

By the way,... I like the user name. I used to use MUADIB (and still od on a newsgroup about VW's,.... related to having a DUNE buggy).

 

Thanks Terrellster, I'll have a friend come over and kick it over while I listen. Perfect nick for a dune buggy newgroup!