Needing a little help with wild throttle

[Nitro Blazer]

I bought a Blaster not too long ago with a smoked top end. I said hell with it and just bought an entire running engine off eBay. I got it Friday and fired it up Saturday after going to get some 2 stroke oil. It fired on the first kick, pulled the front tires everytime I hit the gas. It was running great. Then I get 1/4 mile down the road and push the clutch in and it's trying to run wide open, let it out and it goes back to running kinda normal but it wasn't smoking as mutch as I thought it should. I knew something was wrong so I cut it off and pulled it back home.

The throttle seems to be working ok I took it loose and drained all the fuel out and put it back, fired it up and it idled till I hit the gas, then it went back to wide open. I kinda doubt anything is wrong with the engine, I got it from a reputable seller who has parted many atv's with no problems.

Would not getting enough oil make it run like that? Or is it just the float or something sticking in the carb.

I'm kinda new to all of this but I do have a hanyes manual (almost worthless in this situation). Any help is appreciated. Thanks.

 

[dblaster]

sounds like the pilot jet is wrong or check the air/fuel screw hanyes manual should tell you were its at and were it should be set i think 1 1/2 to 2 1/2 turns out.

 

[Nitro Blazer]

I reset the pilot screw just to be sure.

I messed with it today after I posted. I took the carb off and did a little cleaning, took the reed valve out and I could clearly see that it was not sealed (fuel was running out of the bottom of the intake), so I put some RTV around all of that to make sure it was good and sealed. Then I fired it up and it idled kinda low so I adjusted the idle speed screw and got it so it would idle kinda ok. Then I punched the throtle and it took a while but it came back to idle then I hit it again and it stuck wide open.

I'm thinking it's the carb or the cable. When I took the carb switch apart I saw a spot on the cable where it looked like it used to go lower for idle but it was hanging and wouldn't go down far enough.

How far closed should the carb slide be at idle? How does the engine run if the crank seals are bad?

 

[dblaster]

don't know how far for sure but only a little would be my guess and the crank seals should make it run kinda funny but not stick wide open. did you use the carb off the old blaster or new? Cause the pilot jet might be jetted wrong. that would make it idle high and not want to come down to idle.

 

[Nitro Blazer]

I used the original carb that came with the bike.

I got on it and rode it around the yard once today, it's running rich. Was running lean before I siliconed the reeds and I put a thin layer of RTV around the gasket where the carb switch goes on (it was loose when I got it).

It's not sticking wide open so much now. It will still do it but it will eventually come back down.

It also sounded like it was pinging for a second but I'm not sure. I think I might just buy a good carb of eBay and see what happens. The slide and the bore on this one look kinda scored up. I just don't want to spend the money on a carb and wind up having another messed up engine. Would it be more wise to try and rejet the carb? I'd have to buy the jets but that would be cheaper. I'm just worried the slide is hanging.

Would it ping from using 87 octane instead of 93? I just saw in my haynes manual that 93 is recommended.

Sorry for all the ultra long posts.

 

[Nitro Blazer]

also forgot to mention that I don't know how long the carb sat. The engine that was on it was stock and I bought a stocker to replace it.

 

[dblaster]

93 will make it run better and not ping as bad but i rode mine with 87 for about 3 months and nothing happened but the ping was noticed. you cleaned it so how long it sat shouldn't matter. sounds like the pilot jet is too small and not letting it come back to idle. if you have the money I'd go aftermarket I've had two of three of my blaster carb had to be changed cause something happed to the internals stock one are piles.

 

[Nitro Blazer]

I'd like to go afterarket but I don't want to drop $200+ on a carb and find out I've got a POS engine.

Would it be far fetched to think that the oil in the crankcase when I got it was just left over from the last time it was run and the gas had just evaporated from it leaving it in the case?

If the seals are leaking I'm sending it back and getting my $500 back. It was advertised as a bolt in and go.

Also is it absolutley necessary to crack the case to replace a bad crank seal?

 

[dblaster]

I would try a bigger pilot jet. most shops don't carry it cause it is and odd jet but maybe you'll be lucky. that will be less expensive then a new carb. stock is 32.5 so try 35 or bigger but find out what you have first.

 

[dblaster]

I would not think it sitting enless it was 2 or 3 or more years would effect it. was it running when they pulled? If so how long ago was it. yes i do belive it is neccessary.