Finally have a (kind of) running blaster after combining two (carb / air filter questions)

[ERM9683]

Finally got a running blaster…but it SMOKES like crazy. I know why - it has a 260 main in it. Here’s the mods: pro circuit platinum full system, stage 2 uni filter, and airbox lid is off. Thing is - I rode it a couple times with my stepson; it ran like sh*t at 1/4 throttle…RIPPED above that. I have the necessary jets in the mail to tune it, but the couple of short sessions I had were without filter oil (and on asphalt).cleaned it, but As soon as I oiled it, it wouldn’t start without holding the throttle in a bit. I SWORE I only oiled it lightly…do I need to soak some of that up?? I have these main jets coming (will do a plug chop, but wanted to see if I could get some input): 235 through 250. OH - running 32:1; 93 octane. PO broke it in at 25:1. Apologies for my ignorance, this is my first 2-smoker. Thank you!!


Eric

 

[acdiez]

Sounds like a pilot jet issue to me. If it is ripping 1/4-3/4 throttle (needle) and WOT (main), make sure the pilot is super duper clear as it starts the bike and controls the fuel up to about 1/4 throttle. There are tiny holes in the jet that allow the fuel the vaccuum into the venturi of the carb. May also be the reason your machine wont start after oiling the filter. Would also double check your mixture screw, typically likes to be around 1.5-2 turns out from bottom.

 

[ERM9683]

Sounds like a pilot jet issue to me. If it is ripping 1/4-3/4 throttle (needle) and WOT (main), make sure the pilot is super duper clear as it starts the bike and controls the fuel up to about 1/4 throttle. There are tiny holes in the jet that allow the fuel the vaccuum into the venturi of the carb. May also be the reason your machine wont start after oiling the filter. Would also double check your mixture screw, typically likes to be around 1.5-2 turns out from bottom.

THANK YOU for the input! Would the bigger main jets explain the heavy smoking, though?? I know 2-strokes obviously do that, but this was NUTS…clouded the whole culdesac from my yard! Also - any suggested brand of screwdriver to get those pilots out?? I had a mishap before with my bike, and I had to drive a small screwdriver THROUGH the pilot just to get the damn thing out. Those carbs sat a while, but they were carbs for a 4-banger.

 

[RIDE-RED350r]

I wouldn't start making main jet alterations as you state that it rips from 1/4 to WOT. You issue is on the idle/pilot circuit. Make sure the pilot jet and it's circuit in the carb body is clean and clear, also make sure the idle air circuit is clean and clear. Sounds like you may be rich down low which could be due to a pilot jet that is too large or a stopped up idle air circuit. Either will cause heavy smoking and poor performance on the low end.

 

[ERM9683]

I wouldn't start making main jet alterations as you state that it rips from 1/4 to WOT. You issue is on the idle/pilot circuit. Make sure the pilot jet and it's circuit in the carb body is clean and clear, also make sure the idle air circuit is clean and clear. Sounds like you may be rich down low which could be due to a pilot jet that is too large or a stopped up idle air circuit. Either will cause heavy smoking and poor performance on the low end.

Update: I took both of the carbs into work (I’m a millwright / industrial mechanic in training, and there is a TON of tools / materials that I can use), and soaked the jets in parts cleaner. Sprayed the sh*t out of the carbs as well. Both carbs had a 32.5 pilot in them; the one I was using had a 260 main and the extra carb had a freakin’ 360 in it! I’m going to try to put them on and give’er a go later today.

 

[ERM9683]

Ohhhh yeah, I forgot - the needle on the carb that’s in better shape (the one I plan on using that had the 360 main) has a needle with 6 notches…it’s clipped on the 3rd notch down. Is that an aftermarket performance needle?? Figured it was, because the stock only has 5 notches, yeah??

 

[RIDE-RED350r]

Either that or possibly some AM brand of carb rebuild kit that came with that needle. It may or may not be a good thing, needle taper and profile matters quite a bit and if there was an AM rebuild kit used that was of questionable quality (read Chinesium) it may give you issues.

I always run Keihin jets and needles in my Keihin carbs. And would do the same with Mikuni if I had any of those.