Should I rejet?

Keihin carbs are great, their jetting is a lot easier to pin point vs mikuni. What I mean is, their jets go in smaller increments the mikuni does so they are truely fine tuned. In the same breath, mikunis are very easy to work on and have a great track record. I hope you get your jetting squared away and keep us posted. Good luck!

I will on both accounts. I'm as persistent as I meticulous...even been called persnickety a time or two...that poor fella lost some teeth though. No, really, he was 7 and they were falling out, heard it from his grandfather though, little kids like that shouldn't use such big words. 8-|
 
Ok, order has been placed. Got a new Idle Screw coming (found out tonight that is bent pretty badly), got a #30 and #35 pilots coming (didn't see a 32.5), got main jets in 250-290 coming and they had caps, so for $8 more, I thought it was worth a shot. So, $45 later, I hope I'm covered.
 
Keihin and Mikuni jets use a different method to reach there sizing. Keihin use just a size, While Mikuni uses a flow method for sizes. From what I've read.

Mikuni's aren't that bad for jetting as long as you know what you need. But I like Keihin's needle jets sizing to mikuni's. Mikuni's have diff sizes for the jetting on the tube the needle runs in were Keihin uses just one size but varies the needles more in there diameters.

My problem with jetting a Mikuni carb is the fact that it came off another bike and they have parts that can only be reference to the bikes oem (needle jet and jet needle), And have mikuni stamp. The blaster needle jet is like this also. They don't show up on any were that sells Mikuni parts online. Not knowing the original bike stumps oem searching on my Mikuni carb.
Keihin carbs may also have parts that are oem specific as well.
So I went to the OKO carb I'm using now.
 
Keihin and Mikuni jets use a different method to reach there sizing. Keihin use just a size, While Mikuni uses a flow method for sizes. From what I've read.

Mikuni's aren't that bad for jetting as long as you know what you need. But I like Keihin's needle jets sizing to mikuni's. Mikuni's have diff sizes for the jetting on the tube the needle runs in were Keihin uses just one size but varies the needles more in there diameters.

My problem with jetting a Mikuni carb is the fact that it came off another bike and they have parts that can only be reference to the bikes oem (needle jet and jet needle), And have mikuni stamp. The blaster needle jet is like this also. They don't show up on any were that sells Mikuni parts online. Not knowing the original bike stumps oem searching on my Mikuni carb.
Keihin carbs may also have parts that are oem specific as well.
So I went to the OKO carb I'm using now.

"www.psep.biz" has all the parts that everyone was talking about with the 26mm Mikuni. Mine being a 28mm, I have to up the size. Seemed like all of the parts in my carb were on that website, even the needle jet and the jet needle. The only thing I can't mess with, is what the main jet screws into, that is pinned into place. I guess I haven't read enough to know what you're talking about with the flow method of sizing, but that is ok, I have BF and all her siblings to guide me along on my journey. :D Maybe some day, when I feel like messing more with the Blaster, I will tinker with different carbs, for now though, I just want her running and on the trails...no racing, this little 4 wheeler will be carrying precious cargo. I:I I will look into what you're saying though, never hurts to edumacate ones self.
 
Alrighty, so, my PSEP delivery arrived on Saturday. I:I After an agonizing trip to my buddy's for some checking over his new mudder/rock crawler Jeep project, a sampling of his 5 brands of moonshine and some farting around with Beagle pups, I finally got home to open the box. Well, first thing was first, I had to check out the $8 mixing chamber top (carb cap)...fit like a glove. :eek: Couldn't believe it. Next was to change out the main to a #270 and put in the #30 pilot, check. Finally, it was time to replace the old idle screw with the new one...**sound of scratching record** X(...it didn't fit. There was only one to order, but the needle end that adjusts the slide was .020 to big...damn! Well, a little careful hammering (yes, I used a Hammer :D) and I straightened out the old one. So, that part will be going back to PSEP. After a little tinkering to get the throttle cable adjusted so there was 0 play, it was time to fire it up and see what happened. Kick after kick after kick, it wouldn't start...I was smiling and laughing, looks like AWK is running a Honda sticker the rest of the season. :p

So, after that and a little more tinkering, it appeared I forgot to put the lead back on the plug. :-[ sh*t happens. I fix that, get on, first kick...fired right up. X( I think I'm gonna slap a Honda sticker on his quad anyway, just for threatening to run one. 8-| Anyhow, a little goofing around with the carb I think I got it idling nice, no revving, no stalling, I shut it down and had to vacate the barn because I couldn't see thru all the smoke. Apparently, after the smoke cleared a quick check of the plug, all the oil on the plug was still burnable and boy did it ever.

So, now I just have to find a couple fittings, build my leakdown tester and do my test. Of course, my rear brakes still need a little tweaking and now, with my boredom, I need to replace a front brake cable...adjusting them up and not knowing my own strength I snapped the adjuster nut off the one side. Oy...it's always just one more thing. :-[
 
So, here is some more info and questions to those who know. I've replaced my carb cap, as posted above, but now it seems I don't have the same amount of throttle that I had before. My first question is, this pic is with the throttle pushed all the way until a mechanical stop, is it WFO? I'm thinking not, but I'm not 100%.
0512121743a.jpg


Next question, considering it is not WFO, I got to looking at the slide, and there happens to be a mark going all the way around it, in the pic you will see it just about line up with the foot peg. Did Mikuni (and/or other carb co's) make the mark for TORS removed caps? I did a quick measurement, and by golly this seems to be a good mark in the difference in heights of the caps (old vs. new). It just seems I would have to attempt to cut the slide and then it seems the first picture would appear wide open. Is this something that needs to be done when you remove the TORS?
0512121750.jpg
 
Stupid question but did you slacken off the cable adsjuster, it looks like a lot sticking out of the top.

Nope, good question. I kept adjusting out both adjusters, top of carb and on the throttle, both backed out quite a bit. Anyhow, I kept adjusting them out until there was no play in the thumb throttle.
 
Bumping for night crew and to ask, again, is that line on the slide in the pics above, the line I should cut at to fit it for the TORS removed cap?
 
No, you do not cut the slide for tors removel. There actually should be a little slack in the cable, thumb lever should move a hair before the cable moves. Going have to double check everything. Is the thumb lever moving fully? Is limiter screw turned in or out?
 
No, you do not cut the slide for tors removel. There actually should be a little slack in the cable, thumb lever should move a hair before the cable moves. Going have to double check everything. Is the thumb lever moving fully? Is limiter screw turned in or out?

Limiter Screw is backed all the way out. No, the thumb lever is not moving fully, because of the range of the slide I'm assuming. If I disconnect the cable from the slide, the lever will move all the way...but connect the cable to slide thru the cap, and it is limited. The slide does rest at 0 when the cap is on the carb and the cable is connected, so the cable length isn't an issue, it has to be the combination of the length of the slide vs. the height of the cap. Essentially, if you look at the caps in this pic, you will see a height difference....new cap on left and old cap on right. The slide will fit inside the extra height of the old cap.
0418121842.jpg
 
Well you said tors cap I ASS U MEd it was stock carb, you're retrofitting something else :eek: At this point I guess you could try cutting the slide. Be sure to bevel top like original and de-burr it. Will the slide even be long enough if you cut it? Won't fall off tang that keeps it from spinning out of posistion?
 
Ok, knowing it's only $$$ to replace it, I cut it to the dotted line around the slide. Actually, I cut it short of the line, ground it down the rest of the way and then bevelled and deburred my cut. Now it opens up nicely at 100% throttle, closes perfectly at 0% throttle. I'm thinking, but I can't be certain, that that dotted line was indeed for accomodation for the different caps. So, now we all know another little trick I suppose...buy the slide that has the mark on it. I:I

My current dilemma, now at WFO it acts like it is starving for fuel. It doesn't run smoothly, kinda acts like it is cutting out. When I parked the Blaster though, I noticed fuel running out the tube. I know your going to ask what tube, I don't know for sure what it is, but if you leave the fuel turned on when the machine is parked, it is the tube that gravity will pull fuel out of. Even though I'm riding it, should gas be leaking out of it? I'm thinking I need to bump up a couple more Main sizes...no I haven't Plug Chopped yet, I want it running smoothly around the yard before I haul it somewhere only to find other little issues like this. What else could make it act this way? The needle valve is pulled out of the valve needle, my Main is #270 and I'm mixing 32:1. My leakdown test was perfect, needle didn't move for 30 mins...I forgot about it while I was making a sandwich and watching tv. My compression is 125psi when warmed up. I even put a brand new plug in, factory gap though, what should be the proper gap, I didn't seem to find that on here. The only thing I don't know for sure is the float level...not 100% sure on how to check that yet, then again, I haven't really looked for a detailed explanaion. I know AWK or Slick gave an explanation early on in this thread, I will look back later...gotta go see Mom, being today is Mom's Day and all.
 
Well you said tors cap I ASS U MEd it was stock carb, you're retrofitting something else :eek: At this point I guess you could try cutting the slide. Be sure to bevel top like original and de-burr it. Will the slide even be long enough if you cut it? Won't fall off tang that keeps it from spinning out of posistion?

Yes, I know, you are correct. I called it the TORS cap, to try to avoid confusion...also, I forget this isn't the stock carb on it and I need to 'splain muself better! :-[
 
Spark gap 0.7 - 0.8mm, its in the specs in the manual.

If fuel is coming out of the overflow there must be a problem with the needle and seat, could be some crap in it or it may be wrongly adjusted for level, or sticking

Before you plug chop you need to fix the flooding problem as it will interfere with your readings.

Please explain: The needle valve is pulled out of the valve needle ???????
 
Spark gap 0.7 - 0.8mm, its in the specs in the manual.

If fuel is coming out of the overflow there must be a problem with the needle and seat, could be some crap in it or it may be wrongly adjusted for level, or sticking

Before you plug chop you need to fix the flooding problem as it will interfere with your readings.

Please explain: The needle valve is pulled out of the valve needle ???????

Thanks, I looked and looked but I must've read over the gap spec. I am checking the needle and seat and changing to my biggest main at the moment...can't ride though, neighbors are having a party...and I wasn't invited. X( It isn't absolutely pouring out though, just enough for a 5 minute ride and there is fuel on the guard over the front sprocket.

Needle Valve is pulled out of the valve needle...when I parked it, I pulled the air box off and watched to make sure the slide was moving up and that the needle was opening enough in the valve needle to allow fuel vapors up.
 
Where is the clip on that needle what position?

Float level is 20 to 21.5mm.

No fuel should spill from the carby when parked with the petcock on!
 
Where is the clip on that needle what position?

Float level is 20 to 21.5mm.

No fuel should spill from the carby when parked with the petcock on!

middle position on the clip. Measuring my float levels, I was told 15-17mm earlier in this thread, but measuring that seems like it is going to be different than a physical measurement...maybe I'm wrong. My floats are in the bottom half of my carb and the needle and seat and "flapper" is on the top half...pics below. And I don't have a bowl drain, other than that big hex nut on the bottom...nothing I can hook a tube up to.

I have heard/read other people say that fuel will trickle/drip out the float bowl vent if they don't turn the fuel off on 2-Strokes.

0513121903a.jpg


0513121904a.jpg
 
My bad, I was quoting the stock 26mm setting for the float.

"I have heard/read other people say that fuel will trickle/drip out the float bowl vent if they don't turn the fuel off on 2-Strokes."

If fuel drips or trickles out of any carby, not only 2 strokes, there is a possibility that the needle and seat assembly is not working correctly, because it has dirt or a varnish build up, or has been bastardised.