Blaster Won't Start - About To Give Up - Super Frustrated.

[Blue]

Its frustrating for sure. Weve all been there. Did the motor ever run correctly? Or is it new and if it is Did you assemble it or a builder? Reason i ask is i have seen people install the pistons backward. It will make compression but be difficult to start since it looses crank case vacuum when the piston skirt opens the exhaust to the case when the piston goes up. Its a long shot but it just happened 2 weeks ago to a guy that assembled his own. I read some of the other post and was thinking the keyway might be an issue but if you checked that maybe not.

 

[retroicon]

Its frustrating for sure. Weve all been there. Did the motor ever run correctly? Or is it new and if it is Did you assemble it or a builder? Reason i ask is i have seen people install the pistons backward. It will make compression but be difficult to start since it looses crank case vacuum when the piston skirt opens the exhaust to the case when the piston goes up. Its a long shot but it just happened 2 weeks ago to a guy that assembled his own. I read some of the other post and was thinking the keyway might be an issue but if you checked that maybe not.

Yeah, it did run correctly at one point before sitting for about 8 years. I know that's a long time, but it wasn't my motor. It used to be a race motor that a friend took apart to rebuild, then got busy, and never got back to putting it all back together. I got left the motor and hull when he moved across the country, and had to dig through boxes to find everything. I've probably put together 40-50 motors over the past 20+ years, and looked at the marks on the top of the pistons through the spark plug holes just to be 100% sure. They're the right way.

 

[Blue]

Ok thats good. I will re read the post tomorrow to see if i can think of anything else.

 

[Big Kahuna]

Do you have a different coil to try. That might be your culprit. You said new electronics I believe. JSS coils are far from new. If he did not get the wire all the way set you may have weak or Intermittent spark.

 

[OCD Solutions]

This past weekend I had a customer question one of my modded CDI's because his ski was doing weird things on it's maiden voyage. It ended up being that he had the white wires swapped on the CDI, (this is why I mentioned it earlier). He went in to swap out the CDI with a known good one and discovered the wires. He has it running like a champ now and is kicking himself for such a rookie move.

 

[CRJ]

it sounds to me like the fuel passages in the carb are plugged up. And a 190 main on a twin carb is WAYYY to high. you should be around a 135 at most. id go over those carbs more, if it sat for 8 years, its going to be gummed up and have nothing going to it. priming it proves it runs, so its a fuel flow issue, most likely the micro holes under the butterfly that are your problem.

 

[Blue]

190 does sound huge. My 900cc had dual 46 with
2.3 needle and seat with
110 main and 125 pilot and returns not drilled out and it was always a little rich. He is using 2.5 needle and seat but still sounds like too much. You mentioned when u prime and start it that it revs super high due to all the fuel in the motor but its actually just the oppisite if it was loaded up it would be so rich it would barely rev and smoke like crazy. If u prime it and it revs super high and ur sure the carbs are completly closed its lean and u are not getting fuel to flow thru carbs and feed the motor once it starts. Its possible the low speed circuits in the carbs are clogged up and the high speed is way to rich would also make a motor hard to start then hesitate as its to lean on bottom then choke out as its to rich on top.

 

[Big Kahuna]

190 does sound huge. My 900cc had dual 46 with
2.3 needle and seat with
110 main and 125 pilot and returns not drilled out and it was always a little rich. He is using 2.5 needle and seat but still sounds like too much. You mentioned when u prime and start it that it revs super high due to all the fuel in the motor but its actually just the oppisite if it was loaded up it would be so rich it would barely rev and smoke like crazy. If u prime it and it revs super high and ur sure the carbs are completly closed its lean and u are not getting fuel to flow thru carbs and feed the motor once it starts. Its possible the low speed circuits in the carbs are clogged up and the high speed is way to rich would also make a motor hard to start then hesitate as its to lean on bottom then choke out as its to rich on top.

What Purple said.

 

[Quinc]

 

[CRJ]

Gotta get a small wire and clean the tracks, a solution wont do it. they are small enough to hold an air bubble within the hole when fully submerged.

 

[Big Kahuna]

Thats when you got to agitate the solution to break up the bubbles.

 

[CRJ]

Thats when you got to agitate the solution to break up the bubbles.

Might work, but all that work to have them still be plugged would be unfortunate.

 

[txsuperjetfreak96]

Get a torch tip cleaner


Sent from my iPhone using Tapatalk

 

[Big Kahuna]

That why you take WD40 or carb cleaner and blow through the circuits also. you physically look for the streams to come out.

 

[Tyler Zane]

Ultrasonic cleaner all the way. A local shop might even toss them in for a 6 pack of beer. Then as BK said, blow threw them with cleaner and compressed air.

 

[CRJ]

That why you take WD40 or carb cleaner and blow through the circuits also. you physically look for the streams to come out.

yep! you can see right into the venturi area through the jets

 

[retroicon]

This past weekend I had a customer question one of my modded CDI's because his ski was doing weird things on it's maiden voyage. It ended up being that he had the white wires swapped on the CDI, (this is why I mentioned it earlier). He went in to swap out the CDI with a known good one and discovered the wires. He has it running like a champ now and is kicking himself for such a rookie move.

White wires swapped?

 

[retroicon]

it sounds to me like the fuel passages in the carb are plugged up. And a 190 main on a twin carb is WAYYY to high. you should be around a 135 at most. id go over those carbs more, if it sat for 8 years, its going to be gummed up and have nothing going to it. priming it proves it runs, so its a fuel flow issue, most likely the micro holes under the butterfly that are your problem.

They're clean... I'm sure of it. I've had them apart, and cleaned probably 5 times now. I'd eat off the things.

 

[retroicon]

Do you have a different coil to try. That might be your culprit. You said new electronics I believe. JSS coils are far from new. If he did not get the wire all the way set you may have weak or Intermittent spark.

I'm not sure if I have one or not. Will have to dig around and see what I can find. Is there a way to test them to see if that's the issue?

 

[CRJ]

it runs off prime. its a fuel issue. you can try other things though if you like.

setup your carbs at a 135m 120p 2.0n/s with a gold spring. That will put you at 32psi pop off. screws 1.5 turns out high and low to start, and bring in your idle screw a bit, ive seen people with "no starts" simply cause the idle screw is backed out. That'll be all the fuel you'll ever need for a 760cc. On a single 46 i ran a 150 main, 120p, 2.0 n/s and 95g spring.

with the 2.5 n/s and silver springs you have between 12 and 17psi pop off. lowest you want to be is 25psi, highest around 35psi.

start with getting the carbs in the same area code as where they should be before you dive into electrical on a motor that starts