Blaster 240 keihin flat side carb problems!!

[BlasterKid23]

Okay so recently my 240 blaster blew up because the guy I bought it from ran it lean. The piston over heated and ended up frying it and making it look like used charcoal. it lost all compression. So, I was looking on craigslist for a any top ends or anything. I found a guy with a great condition, used 240 vitos top end. barely any hours on it. It came with a fat bastard full exhaust, k&n air filter, 34-36 keinhin flat side carb, v force 3 reeds and a boost bottle. So, I bought all this for 450$ put the top end on, checked everything, everything was tight. I hooked up the carb, shot some started fluid through the carb and it started after 10 kicks. I had to buy the tor eliminator kit to fit the new carb. So, when I hookedup new cable, it seems alittle short. All the way adjusted still made the slide not sit on the bottom of the carb. Now the quad runs good but it runs pretty rich on 32:1, so I leaned mix alittle to 40:1 now it smokes less and seems to run better & I noticed it doesn't run good with the air box lid on. So the problem now is that it seems that I cant get it to run right. Right how it starts on like 2-3 kicks but with choke on it seems to rev really high, alittle too high for choke. Then with it off itll idle at a good idle for like 5 secs then die on me. Also, the idle screw doesn't work at all, it doesn't do anything turning it in or out. So, I feel that either the jetting is off which made it run rich on 32:1 or its made to just run on 40:1, but it seems that it runs good other than idle. I don't know much about carbs. So I really need help. I adjusted the air/fuel screw near the air filter side of carb. its about 2 turns out. Another thing is that the throttle cable when you pull it away from the throttle assembly it causes it to rev. if any of you can give me your take on what you think is going on. Let me know. I don't want to mess anything up by running it lean or rich... First time doing a rebuild by myself and working on a carb by myself. So, im alittle stuck and just don't want to mess the quad up. Got too much into it.

Oh yeah and one last thing is that the new exhaust, seems to shoot oil out of it and its splattering onto the frame. this is another reason that made me think the jetting and the 32:1 was too much oil. not sure if its missing a seal or gasket but it shouldn't be shooting any oil on the frame

 

[tbrooks]

Welcome to the forum! Where to start? First and foremost leak test if you haven't. You don't change your mix ratio to compensate for rich or lean conditions normally. If it runs better with the lid off it does sound like a rich condition. Sounds to me like the jetting on your carb is off. Mainly the pilot if it has prob at idle. To run the same jets that came in the carb ur bike has to be setup the same as the bike the carb came from and then there will still be differences due to temps and elevation.
Leak test first!
Idk about the jet sizes for that carb but someone else will chime in
Clean carb
set float
adjust idle and air screw
plug chop to confirm jetting

 

[bansheedave]

should not have to of bought a tors eliminator kit for a keihan flat slide carb. the makuni cap will not fit. second, ether is not good to use on a 2 stroke. and after 10 kicks, it has to be a worn top end. compression test it. leak test it. and measure the piston and bore to be sure it really is a big bore kit.

get the correct cable. start the ait mix screw at 1and a half turns out. if it is a keihen flat carb, start the pilot out at 42-45 and the main at 165-170 than plug chop. it should start on at least 2 kicks if it was a fresh top.

 

[BlasterKid23]

Okay so to update you guys it does start on first kick. It did need a tors elim kit because the end of the tors doesn't fit into the carb. Also, I ran 40:1 because it was really rich & people told me it could help. So it still runs good with the 40:1 mix. Is it bad to run at 40:1? As for the idle screw not working is this because cable is too short? Also the guy told me the jetting was set for the kit. To answer the question yes it's a 240, the piston said Vito's and he had original box and all. It runs good just doesn't want to stay on during idle. It flys though when you ride it. It has 120 psi according to compression test.

 

[BlasterKid23]

I ordered a cable that's made for an aftermarket carb today. So hopefully it comes in and solves the short cable problem. Hopefully making the idle screw work again.

 

[jus_me]

First off welcome to the forum.. Secondly you need to make sure you have no air leaks or you will NEVER be able to get your carb tuned in.. So buy, build or rent a leak down tester, perform a proper leak test then a compression test and go from there.. Also while you have the carb off give it a good cleaning and let us know what jets r in there? When your tests are all good we can focus on the carb..

 

[BlasterKid23]

So what I don't get is how is the jetting off if it rides and runs amazing when riding. It idles but dies when idling for longer than 5 seconds. It runs rich when it's 32:1.. With 40:1 it runs alittle rich still but like a normal blaster

 

[jus_me]

Have you performed a leak test? Also have you cleaned the carb well and checked float height..

 

[BlasterKid23]

Going to buy a leak down tester and see what happens I'll let you know in a few days when I get it in the mail. Thanks guys. Get back to you later this week

 

[Blaaster]

You are confusing lean and rich mixtures, there is oil rich terminology and fuel rich.

If you use less oil you actually create a fuel rich condition which can create plug fouling problems.

The black spooge you refer to is caused by a leaking header pipe which will cause a lean condition and will create jetting headaches.

Changing to a 40:1 ratio and putting the air box lid on will tend to cause an over rich AFR.

You need to visit the tight throttle cable, if it is so tight that the slide does not reach the carb bottom, then of course the idle screw will not be able to control the slide and idle will not be adjustable.


To save chasing your rear end continuously do the following.

Fix the exhaust pipe leak.
Correct the throttle cable.
Leak test the engine.
Set float level.
Adjust idle.
Mix at 32:1.
Plug chop to confirm the jetting.

32:1 is not too much oil for a 200cc engine, it is what is preferred by 95% of Blaster riders.
I am one of the 5% that choose to mix outside the box at 25:1, for extra engine life and better compression.

However there is such a thing as too much fuel, the AFR must be correct for correct combustion.

As to correcting the AFR by altering the fuel to oil ratio, it is something that I do often, it allows me to fine tune the AFR for varying altitudes.
It is not a common practice, but it sure saved me taking the carb off in a dirty, dusty pit area.

Messing with a tight cable, leaky header, varying AFRs, leaky engine is not going to give you anything but a headache.
Correct your problems and start afresh!

 

[98blaster]

What keihin carb do you have pj or pwk? The pj has the idle circuit an choke circuit combined into one circuit, pwk has seperate idle an choke circuits an in my opinion is easy to tune an performs better then a pj. Most likely the cable you going to get thats for aftermarket carb is same cable that came with tors eliminating kit, motion pro 01-0874 is the number that you probably got, but that cable may have issues with that big carb, awk uses one on his pj 34 with no issues, but we dont know what your carb is yet...

 

[Bluesman]

Look at the numbers/letters on the side of the carb. If it's a PJ it will have "PJ" cast in raised letters. If it's a PWK, it will have numbers/letters stamped that correspond with this chart.

http://www.sudco.com/pwk.html

 

[Awk08]

never, ever, ever go by what a previous owner tells you. he'll tell you whatever is required to make the sale.
who knows what bike that carb came off of ? or if it was ever properly set-up for a blaster ?
just because it idles or feels good at certain throttle positions doesn't mean it's jetted correctly.

99% of the PJ's and PWK's from other bikes require rejetting for a blaster engine, 200 or 240cc.

45-50 pilots
CEL or DGH needles (MUST HAVE !)
150 - 165 mains

jetting on my 34mm PJ @ 1800'+ above sea level is 48p/dgh needle/155 main.
sea level will require richer jetting, mile high denver will need leaner.
start with a leakdown tested, leak free engine,
then onto each seperate circut of the carb jetting, starting at the bottom and working up....
float height, pilot/airscrew settings, needle, and then plug chops for the main jetting < start large and work down.

there are stickied threads at the top of the engine/carb section on most of the procedures for each jetting circut.

and......open the back garage door and throw that can of starting fluid as far as you can
it should never be used on a 2 stroke unless it has a 32:1 oil mixture in it, and i've never seen such a thing.

 

[Blaaster]

throw that can of starting fluid as far as you can
it should never be used on a 2 stroke unless it has a 32:1 oil mixture in it, and i've never seen such a thing.

I mix my own starting fluid, 25 parts of fuel, 1 part of Oil.

Put it in a hand atomiser bottle, and squirt it into the intake tract, post filter.

Works every time, costs very little.

 

[rich1]

Starter fluid ? Just use WD -40 starter and oil together works great.

 

[Awk08]

i say don't use anything to try and start it, except the fuel/oil mix thru the carb,
if it won't start within a few kicks...somethings wrong.
find and fix the problem until it starts easily on it's own.
getting it started with anything but it's own means serves no purpose and doesn't fix the underlying problem.

 

[Larry's Shee]

With a to short cable would seem you couldn't get it to idle low enough.
XX-2 on leak test. Blaster I'm working on air screw did nothing 1/4 turn either way. I'm like wtf? Next thing I know it's racing to the moon. Clutch sid e seal blown out, no wonder it was hard starting.

 

[Blaaster]

i say don't use anything to try and start it, except the fuel/oil mix thru the carb,
if it won't start within a few kicks...somethings wrong.
find and fix the problem until it starts easily on it's own.
getting it started with anything but it's own means serves no purpose and doesn't fix the underlying problem.

I am fully in agreeance with Awk, if it won't start without starter fluid, fix it till it does.

If a problem exists at starting level it usually esculates further up the chain, and engines can be destroyed!

 

[BlasterKid23]

Okay so, took it out today. I did a leak down test it turned out good no leaks, which I was very happy about. It starts first kick with no choke. The only reason I did that with starting fluid was to see if I got any response from spark plug, at first I thought the timing of the plug and when the piston reached tdc. But no now it starts first kick no choke. The problem I have now is. I got a stock cable a while ago for tors eliminator. This cable is definetly too short because it doesn't make the slide sit on the bottom of the carb making the idle screw not even work. So now the idle is basically dependent on the cable. It messes up the way it runs because it idles alittle up and down because If you move the cable in any weird ways it either lowers the idle or makes it rev up really high. So I ordered a new "aftermarket carb cable" from a guy on ebay. Hopefully this fixes the problem. Other than that the bike going down the street screams & it's smoking normal now. Minimal white/ blue smoke is comming out. But very little after I warmed it up. The only thing a tiny tiny bit I noticed was at low rpms it bogged a tiny bit until it hit the power band. But if you rip through gears it runs really good. Could bog at low rpms be jetting?

 

[BlasterKid23]

I'm going to upload a pic of the carb I have on the blaster right now