BLASTER PROBLEMS (WON"T RUN)

[johncam25]

I have a 03 Blaster. I put a new CDI Box, Coil, FMF Exhaust with Core 2 silencer, 28mm Keihin Carb (#230 main jet, also tried a #135), Spark Plug, K & N Filter, and Stator. I bought it without it running, it didn't have a carb with it.

I had the compression tested and its 120-125psi.

I kick it about 25 times and then I get a really big back fire with flames out the exhaust. About the 35th kick it will run for about 10secs and die right away. It needs the choke to start. I have been trying new thing for about 2 months and nothing.

Has anyone heard of this problem? Please help!!!

Thanks

John

[2fun]

Originally Posted by johncam25

I have a 03 Blaster. I put a new CDI Box, Coil, FMF Exhaust with Core 2 silencer, 28mm Keihin Carb (#230 main jet, also tried a #135), Spark Plug, K & N Filter, and Stator. I bought it without it running, it didn't have a carb with it.

I had the compression tested and its 120-125psi.

I kick it about 25 times and then I get a really big back fire with flames out the exhaust. About the 35th kick it will run for about 10secs and die right away. It needs the choke to start. I have been trying new thing for about 2 months and nothing.

Has anyone heard of this problem? Please help!!!

Thanks

John

If I were you, I'd get a stock carb and put it on (I thought the stock carb was a 26 mm??), anyway, I'd put it ALL back to stock including the airfilter, then put the carb back to the stock jetting.

The compression you quoted sounds a bit low to me??

[johncam25]

yes stock is a 26mm, but I ran out of money. I thought that stock jetting was #230 main and #32.5 pilot, but I could be wrong. The carb I have is close to that, and its is also new. I was told that the compression is good.

Thanks

[2fun]

Originally Posted by johncam25

yes stock is a 26mm, but I ran out of money. I thought that stock jetting was #230 main and #32.5 pilot, but I could be wrong. The carb I have is close to that, and its is also new. I was told that the compression is good.

Thanks

The carb you have is a bit bigger than stock, so the jetting is probably going to be a bit different I would guess.

I was suggesting to go with stock size and stock jetting with the original carb. You have also thrown in other variables such as the aftermarket pipe and silencer.

When I had my Blaster with aftermarket pipe and silencer, I was running a 290-310 (I believe) main jet.

The needle position and pilot will ALSO have to be changed to compensate for this.

Thats why I was suggesting you go back to stock with everything (carb, jets, airfilter, pipe, etc), get it running properly, and then move forward from there with mods one at a time (jetting for each mod as you go)

[johncam25]

Originally Posted by 2fun

The carb you have is a bit bigger than stock, so the jetting is probably going to be a bit different I would guess.

I was suggesting to go with stock size and stock jetting with the original carb. You have also thrown in other variables such as the aftermarket pipe and silencer.

When I had my Blaster with aftermarket pipe and silencer, I was running a 290-310 (I believe) main jet.

The needle position and pilot will ALSO have to be changed to compensate for this.

Thats why I was suggesting you go back to stock with everything (carb, jets, airfilter, pipe, etc), get it running properly, and then move forward from there with mods one at a time (jetting for each mod as you go)

Do you know what jetting I should have in the Keihin carb, I would put it back to stock but I got it without a carb and air filter. I don't have the money to buy another new(stock carb and filter).

[2fun]

Originally Posted by johncam25

Do you know what jetting I should have in the Keihin carb, I would put it back to stock but I got it without a carb and air filter. I don't have the money to buy another new(stock carb and filter).

You are using a KEIHIN carb??? I thought you were still using a Mikuni.

Well, I am unsure of the Keihin jet that would match up with a Mikuni. There may be some kind of conversion chart SOMEWHERE on the I-net, but i don't know where it is right off hand.

My GUESS and its only a GUESS is that you would want a slightly larger than stock pilot for that carb, try the needle on the middle position, and a 160 main jet. Again, this is just a GUESS.

Be sure to do a few plug check with these jetting settings though. You don't want to burn up your motor!

[TRXman86]

When I put my pipe and silencern, I ran a 290 main, stock needle position, and stock pilot. I had a UNI filter and ran 6 vents in the lid. Try to run a size larger main, raise the pilot one size also. I will look up the gap, but you can call a dealer for any ATV shop and they can tell ya. You may double check all your wires also. Maybe one is loose around your coil or stator.

[johncam25]

Originally Posted by 2fun

You are using a KEIHIN carb??? I thought you were still using a Mikuni.

Well, I am unsure of the Keihin jet that would match up with a Mikuni. There may be some kind of conversion chart SOMEWHERE on the I-net, but i don't know where it is right off hand.

My GUESS and its only a GUESS is that you would want a slightly larger than stock pilot for that carb, try the needle on the middle position, and a 160 main jet. Again, this is just a GUESS.

Be sure to do a few plug check with these jetting settings though. You don't want to burn up your motor!

I have the needle in the middle postion and I am using a #235main and a #45.5 pilot

[johncam25]

Originally Posted by TRXman86

When I put my pipe and silencern, I ran a 290 main, stock needle position, and stock pilot. I had a UNI filter and ran 6 vents in the lid. Try to run a size larger main, raise the pilot one size also. I will look up the gap, but you can call a dealer for any ATV shop and they can tell ya. You may double check all your wires also. Maybe one is loose around your coil or stator.

So should I try a #290? I think the pilot is a #45.5 and the main is a #235. What size pilot should I try? I checked all the wires, the coil is new and the stator is new also.

Thanks

[TRXman86]

Gap for the plug is .028 type is NGKB8ES.

[johncam25]

Originally Posted by TRXman86

Gap for the plug is .028 type is NGKB8ES.

K, I will try that.

Thanks

[TRXman86]

To be honest, I am not sure how the pilot size increases. I say just use trial and error. Take notes of EVERYTHING you do. That way if what you come out with is worse, you know where to start again. Go one step at a time. Almost forgot, when you oiled your filter, how much did you use? To much on it will make it suck thru the carb and plug the jets. I know from bad experiance

Also, do a search here on the boards for blasters. There have been many questions asked. You may also find even more stuff to help out.

[johncam25]

Originally Posted by TRXman86

To be honest, I am not sure how the pilot size increases. I say just use trial and error. Take notes of EVERYTHING you do. That way if what you come out with is worse, you know where to start again. Go one step at a time. Almost forgot, when you oiled your filter, how much did you use? To much on it will make it suck thru the carb and plug the jets. I know from bad experiance

Also, do a search here on the boards for blasters. There have been many questions asked. You may also find even more stuff to help out.

I didn't oil my filter, it was pre-oiled I guess.


SPECS:
PWK 28MM 29S, Main -#135, Slow Jet -#38 ,Jet Needle -46JJH
Thr Valve- C.A. 3.5

[2fun]

Originally Posted by TRXman86

When I put my pipe and silencern, I ran a 290 main, stock needle position, and stock pilot. I had a UNI filter and ran 6 vents in the lid. Try to run a size larger main, raise the pilot one size also. I will look up the gap, but you can call a dealer for any ATV shop and they can tell ya. You may double check all your wires also. Maybe one is loose around your coil or stator.

He said he was using a KEIHIN carb. He does NOT want to go into the upper 200's for a main jet with a KEIHIN carb!

Keihins and Mikunis do NOT use the same numbering sytem for jets!!

Try to go with the set up I last mentioned.

[johncam25]

Originally Posted by 2fun

He said he was using a KEIHIN carb. He does NOT want to go into the upper 200's for a main jet with a KEIHIN carb!

Keihins and Mikunis do NOT use the same numbering sytem for jets!!

Try to go with the set up I last mentioned.

I called a yamaha dealer and he told me that #290 for keihin is way to big, but he doesn't know what size. I think I have a #135, 168, 170, and 235. and a #35-40 pilot not to sure. Sould I keep the needle in the middle?

Thanks

[johncam25]

Originally Posted by 2fun

He said he was using a KEIHIN carb. He does NOT want to go into the upper 200's fpr a main jet with a KEIHIN carb!

Keihins and Mikunis do NOT use the same numbering sytem for jets!!

Try to go with the set up I last mentioned.

I just tried a #165 and still nothing, it doesn't even want to back fire anymore.

[2fun]

Originally Posted by johncam25

I just tried a #165 and still nothing, it doesn't even want to back fire anymore.

The main jet has nothing to do with the quad starting. The main jet is for 3/4 to full throttle.

The needle is approx 1/4 to 3/4 throttle.

The pilot jet is for off idle to 1/4 throttle.

Take a look in the Knowledge base forums for jetting info. There is a lot of good info there!

Like I said as far as carb adj for the blaster on the Keihin, I am only guessing.

You are not only using a different carb, but also one that is bigger than stock!

Do you have spark??

[johncam25]

Originally Posted by 2fun

The main jet has nothing to do with the quad starting. The main jet is for 3/4 to full throttle.

The needle is approx 1/4 to 3/4 throttle.

The pilot jet is for off idle to 1/4 throttle.

Take a look in the Knowledge base forums for jetting info. There is a lot of good info there!

Like I said as far as carb adj for the blaster on the Keihin, I am only guessing.

You are not only using a different carb, but also one that is bigger than stock!

Do you have spark??

yes I have spark. Should I just buy a stock carb then? It would save alot of time.

[2fun]

Originally Posted by johncam25

yes I have spark. Should I just buy a stock carb then? It would save alot of time.

That was my 1st suggestion.

At least you'd have a ballpark idea in which to start.

[2fun]

PS, I could be wrong, but that compression still sounds a bit low. I know the stock compression on the Banshee is about 120-130 on each cylinder, and they run at a lower compression than the Blaster does.

I've been trying to research it, but I get varying results, not to mention that compression gauges (most anyways) do not usually give a correct reading.

The one I had was off by about 20 PSI, and my friends was off even further. Just something to keep in the back of your mind.