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  • #52094

    Randy McKee
    Participant

    Alan, thanks for the pics. It looks like your conversion was done by someone different than mine or perhaps because it’s a different carb (I misspoke earlier; my carb is a PWM not ‘K’, so that might explain the differences)

    Your evac is closer to front of carb and as you said it’s might be lower in the bowl. It also appears to be straight (mine curves into the bowl).

    Hmmm…  I think I’ll have to runs some more testing and see if I can narrow it down jetting wise.  It may have been way too fat on the bottom last time out; it felt like I was short-shifting everywhere but shift points were normal rpm wise (and over-rev was fine).  I might try Fastech to see if they have access to the conversion specs.

     

     

    #51968

    Randy McKee
    Participant

    Hi Todd,

    Wow they up to 4 rings now on the manifolds?  I have 3 after-market manifolds; two with 2 rings and another with 3 and I think the 2 worked better.  They both seemed to last for about 3 to 4 track days with the viton o-rings.

    The biggest problem I ran into with the o-rings was trying to get the pipe over them without cutting them.  I think that’s why the 2 rings worked best (easier to get the pipe over just 2 o-rings).  Not sure if that’s what you are experiencing. If so, try using just 2 rings closest to the motor and use plenty of lube when putting the pipe over them. Also, make sure your o-rings are the proper size.  I know there are at least 2 sizes out there.  If the rings are loose, they are too big and won’t seal very well.

    BTW: The after market manifolds/o-rings became such a pain in the buttox that I went back to the stock manifold with rtv silicone.  Much easier and it last a couple of track days.

     

     

    #51830

    Randy McKee
    Participant

    Hi Todd,

    Thanks for the tip on the gearing.  I figured an 18/22 might be a good starting point.

    The injury thing must be going around.  I messed up at Streets of Willow and ended up in ER.  Hope you get better soon and we’ll go drafting again (is that beer or main straight?  can’t remember)

    #51733

    Randy McKee
    Participant

    Noah,

    If it still has the floats, it’s a stock carb.   The floats are removed as part of the pump-around modification and the evac tube is added.  Thanks for the offer on the pics, but your carb doesn’t have that tube.

    #45846

    Randy McKee
    Participant

    Where is it causing interference?  Example: it’s hitting motor on right near front right or it’s too tall and crunching my armpit. Nah, forget that… call Ribtect, explain the situation and get the right answer.  877-RIBTECT

    #44979

    Randy McKee
    Participant

    Check with Fasttech.  I’m not sure if they still handle the modification, but it’s worth asking them.  It says it includes pumps, so not sure if you could work a deal:

    http://www.fastech-racing.com/pump-around-modification.html

    #44659

    Randy McKee
    Participant

    Hard to tell too much about the jetting from here and there are so many things that can affect it.  First, how do you know it’s rich?  Did you read the plug or piston top?  It could actually be lean if it’s causing a hard ‘bog’ out of the corner.

    The outside temp does affect the air but, it can be so different from day to day (or hour to hour).  A weather gauge is your best friend when trying to set jetting based on air changes.  Anyway, if you’re used to running safe jetting and it usually works, don’t worry too much about that right now.

    Check your plug to verify jetting and work from there.  It could be your pilot, needle, main, pumps, floats etc.  Any could cause the problem, but since you mentioned new pump and floats, my guess is:

    Fuel pump isn’t working correctly which would mean it’s lean. (this could also be caused by a pinched fuel line or tank pickup problem)

    Floats aren’t set (or maybe stuck) and it’s could be lean or rich.

    What’s the fuel sitch?  Do you know it to be good fresh fuel?

     

    #41577

    Randy McKee
    Participant

    Doug, that was an amazing 1st lap in the 3rd video!  I haven’t watched the end yet, but you are catching everyone like the dinner bell just rang (and you are a STARVING lunatic)

    Edit…

    Oops.  I guess that was one of the Mikes in the 3rd vid.  Don’t know the guy, but he was flying.

    #41527

    Randy McKee
    Participant

    The difference is probably in components.  The kart in your link appears to have aluminum wheels, standard pills instead of independent caster/camber in the front, inexpensive seat, and probably cheap aftermarket axle.  I’m just guessing at these items, but that’s usually where a vendor will make concessions to reduce the expense for an entry level kart.  Even if all of that is true, it’s still a nice deal at $3500 shipped.

    The Righetti Ridolfi components I’ve bought were all very nice.  They’ve been around for a long time, so support shouldn’t be a problem.

    Has anyone seen one of these in the States?

    #41523

    Randy McKee
    Participant

    It does appear to be a real shifter kart for KZ application.  I don’t know what you saw (ebay probably), so I can’t speak to that particular deal,   $3500 is a really good price for a new complete roller.  Anyway, the viper looks like it’s a gold kart made by RR (so yes, it’s Italian).

    Might be able to get more details here:

    http://www.goldkart.com/kart.php?id=119

    #41191

    Randy McKee
    Participant

    Your’s is a single pump fuel system.  As Greg said, it should be fine.

    A pump-around system uses 2 pumps and a modified carb to work with 2 pumps. 1 pump is for feeding carb and the other to scavenge the excess and send it back to the tank.

    Here’s a pic:

    http://www.fastech-racing.com/pump-around-modification.html

    #40783

    Randy McKee
    Participant

    You may want to get a hold of Nick at http://firestonekartinfo.com

    He’s done quite a bit of data analysis and can probably help you out.  Check out these articles he did on the topic:

    http://firestonekartinfo.com/?cat=183

     

    #40782

    Randy McKee
    Participant

    A common problem… mushy brakes that is.  When you replaced the seals, did you do the caliper as well as the master cyl?

    You may have a very tiny leak near a fitting on the brake lines.  Those are tough to find, and it doesn’t take very much air getting sucked-in to cause mushy/fading brakes.

    #39909

    Randy McKee
    Participant

    Diego,

    Need some more details.  Are you checking the clutch with the engine running and warm or is it just sitting cold?

    Was the clutch properly disengaging before you stored the kart 4 months ago?  If so, the cable is probably is set correctly, but it’s easy to check it. Pull the clutch lever and look at the inside of the motor (near seat) to see if it’s moving the clutch engagement lever.

    The clutch will always have some bite even when completely disengaged and it’s even more bite when cold (the clutch fluid is very thick when cold).  Also, the clutch plates will occasionally stick together when they’ve been sitting still for a long time.  You can usually just put it in gear, pull in the clutch and rock the kart back and forth until they break free.  It will probably help to start the motor and warm it up for a few minutes.

    Hope that helps, but let me know if not and we’ll try a few more things.

     

     

    #39746

    Randy McKee
    Participant

    Yep, in fact you can even negotiate on groceries.  I’ve never done it, but I’ve witnessed it a few times at checkout.

    Keep in mind most kart shops are dealing with small margins to begin with, so you’re wiggle room may be less than buying an expensive TV or car.

    #39431

    Randy McKee
    Participant

    P.S.

    One more type of bog, but probably not the case.  Many drivers tend to use too much of the lower power band and the motor bogs when it’s too low in the rpm range.  In other words, it’s not ‘on-the-pipe’ when they get on the power.  Anyway, if you think you’re too low on the rpm’s, try a lower gearing (or shift down one more) to keep it rev’d up.

    #39430

    Randy McKee
    Participant

    Oh yeah…. has the pump been rebuilt and in good order?  That’s often a culprit.

    #39429

    Randy McKee
    Participant

    Can you describe what you mean by bog and which type of turns?  There’s a couple types of bogs:

    1.  motor falls completely flat and feels like it’s sucking air.  No power at all.  This is usually a severe lean situation at some point in the carb (fuel delivery, pilot, needle, main).

    2.  motor has some power but is very sluggish (not crisp when getting on throttle).  Usually too fat.

    I run a cr125 with a pump-around, so I may not be the best to advise you.  However, most of the people I’ve known who run a stock carb/pump setup don’t have significant fuel issues coming out of turns.  They may hickup or fall-flat in longer turns, but are OK otherwise.

    Have you tried different pilot jets?  You may be too rich or lean on the bottom end of the jetting?  I know you can’t try anything for  a while, so you may want to try different jetting setups instead of a pump-around.

     

    #38835

    Randy McKee
    Participant

    Hey Jordon,

    Is it the keihin PWK 38?  If so, what does it include? e.g., installed jets, slide, needle, pumps.

    Thanks,

    Randy

    #38661

    Randy McKee
    Participant

    I’ve never seen those sold separately.  Call some kart shops to see if they’ve pulled/plugged one and can send you the one that was removed.  Or maybe if they have some scratched old 2001 heads laying about, they could just give you that, and then you can transfer one of the spigots to your good cylinder head.

    For a quick fix, you can probably find a suitable water fitting at the hardware store.

    #37515

    Randy McKee
    Participant

    Robert, another thing I just considered… if it’s a 2000 to 2002 cylinder (I think?) hold off on removing the plugs.  Those years have difficult plugs and can’t simply be re-installed.  I believe those have to be glued in place.  Anyway, tell us the year of the cylinder and any other details about the ‘blow-ups’ and maybe someone else can chime in with suggestions.

    P.S.  I could be wrong, but I don’t think the power valve is the reason for the blow-ups.  I believe people used to just wire them open and run it that way (before plugs were readily available).

    #37484

    Randy McKee
    Participant

    Ooh!  sounds worse than I thought.  Usually the plugs will have a very slight leak if any.  I’d pull ’em and see what’s up.

    What year is the cylinder?  If it does need new plugs, you can get the o-ringed type from Swedetech (depending on cylinder year).  If the cylinder is modified, you’ll probably need to reshape the new plugs to match.  Hope you don’t have to go down that road though.

    #37424

    Randy McKee
    Participant

    Do you mean power valve plug or manifold?  I’m  assuming you mean power valve because you mentioned ignition side.  Yes, it’s common for them to leak, but it’s usually not a huge performance problem… just a mess and it’s hard to do a proper leak test.

    If you only put rtv on the exterior, try pulling it from cylinder, swab in rtv and re-install.  Be sure to cleanup any excess rtv inside cylinder.  If it’s an o-ringed type, put a new o-ring on it.

     

    #37411

    Randy McKee
    Participant

    Freddy, you may already know this, but thought it worth mentioning….

    Michael and Jimmy are talking about 2 different Button willow tracks.  1.47 is for the kart track (Jimmy is the man there for sure) and Michael’s gear combo’s are all for road-racing tracks.  19-24 is for the car track at Button Willow.

    #34656

    Randy McKee
    Participant

    Tyson,

    I’m in southern California.  Probably a bit too expensive to ship to you.  If you want to set it up, I can drop it at a depot.  You’d have to arrange the carrier, crates delivered to depot on my end and pay for all in advance.

    Thanks,

    Randy

Viewing 25 posts - 1 through 25 (of 30 total)