Hello I'm new to the forum. I just bought a blaster about a month ago, (always wanted a quad now figured time to get one.) The one I bought had a really badly frame repair job and had a hole in the piston. I got a good rolling chasis for the engine. This weekend got the cylinder all honed out and got a new pison in. Every thing was going good until I got it in the wheeler and started kicking. Tested the stator because it was getting weak spark turned out bad so put another one in. Now I have great spark but it is back firing and it will only start if I use a bit of starter fluid. I tryed ajusting the stator a couple times to get the timing right. I'm wondering if it could be caused by the tors unit or the cdi that it is backfiring. Also there is throttle lag when it runs it throttles up fine but when I let off it stays at high rpms for a second before dropping in rpms. The machine was kicked over without the spark plug grounded out I was told that can fry a cdi and stator. Is there any way to check to see it the timing is off? Or if the cdi is maybe sending spark when ever it wants rather then when it should? I have sheared 2 crank keys so far from back fires. Thanks. Sorry its so long. Ha ha
almost got my blaster running but now am stumped.
- Thread starter viper55025
- Start date
yeah, there is no need to adjust the timing on these to get it running, it is factory set with the flywheel key
was the new stator installed in the correct positon ?? i assume it could go in the opposite position ???
are the grounds connected to the frame good ???? < black wire at the coil
all other electrical connections good ???
piston in the right direction ??? arrow facing forwards ???
pipe free and clear of any obstructions ????....mice like to make nests in ones that sat for long periods, i just built one that was completely clogged, popped the pipe off the cylinder and it fired right up, used a coat hanger to dig out enuf old shirt/fiberglass and plastic to fill a small bucket
was the carb disassembled completely and cleaned ??? what jets ???
airfilter cleaned and oiled ???? intake free of obstructions ???
try unplugging the "tors brain" < 3 wire box under the hood
and most importantly....was it leakdown tested ????
were the head and base bolts torqued correctly ???
did you use new gaskets ???
was the new stator installed in the correct positon ?? i assume it could go in the opposite position ???
are the grounds connected to the frame good ???? < black wire at the coil
all other electrical connections good ???
piston in the right direction ??? arrow facing forwards ???
pipe free and clear of any obstructions ????....mice like to make nests in ones that sat for long periods, i just built one that was completely clogged, popped the pipe off the cylinder and it fired right up, used a coat hanger to dig out enuf old shirt/fiberglass and plastic to fill a small bucket
was the carb disassembled completely and cleaned ??? what jets ???
airfilter cleaned and oiled ???? intake free of obstructions ???
try unplugging the "tors brain" < 3 wire box under the hood
and most importantly....was it leakdown tested ????
were the head and base bolts torqued correctly ???
did you use new gaskets ???
I don't know much about carbs so my neighbor tore down the carb and looked at anything that could get clogged like the jet, needle and seat, pilot jet. All looked good. Still soaked it down with carb cleaner anyways. I got a whole new gasket set and used all new gaskets yes. The stator I put on I put on the way the old one was taken off. We tried to run it before we put on the intake and filter so it was open carb. I'm not sure about if the exhaust pipe is clogged or not but it did run on the starter fluid. I talked to a guy at work and he thinks maybe the key is shearing while it is running causeing the backfire and it not wanting to start. I'm fairly certain the piston is in the right way. We didn't torque the heads to a spec. But we did tighten them in sequence and it has good compression. The engine does make a squak noise sometimes when it pops off. My neighbor says he thinks it is an exhaust leak. I'm not really sure what a leak down test is? Ill try unplugging the tors this weekend and Ill look into the possible clogged exhaust. That is if I can find some more flywheel keys this weekend. Ha ha. Thanks for all the advise. When I get it done I'll post some pics.
If you are shearing flywheel keys like you are, either the taper on the shaft, or the flywheel is damaged, or you are not putting it on tight enough. You need tighten the nut real good 53ft lb.
stop using starter fluid to start it, unless you know of and have some special starter fluid that has 2 stroke oil added to it, you're basically starting it without oil when you do that
pop the exhaust off the cylinder and see if it starts, that'll tell if it's a clogged exhaust problem
pop the exhaust off the cylinder and see if it starts, that'll tell if it's a clogged exhaust problem
Ok this weekend I got the blaster to run with out backfireing. I tighted the flywheel down good and tight. But when it starts and I rev it up it runs away. All new gaskets. Cleaned the carb out twice. Tried 2 different carbs both cleaned twice. Ordered new factory reeds. I got some power reeds from dennis kirk but when I put them on there is a air gap at the tip of the reeds. So I have ordered factory reeds. I really don't know what to do. The throttle isn't sticking but it acts like it is.
running away is an airleak, even the best of new intake gaskets will leak sometimes
it needs leakdown tested !!!!!!!!!!!!!!!
http://www.blasterforum.com/do-yourself-20/videos-how-perform-air-leakdown-test-31464/
http://www.blasterforum.com/do-yourself-20/build-use-leakdown-tester-10663/
contact slickerthanyou on here, he builds and sales them
it needs leakdown tested !!!!!!!!!!!!!!!
http://www.blasterforum.com/do-yourself-20/videos-how-perform-air-leakdown-test-31464/
http://www.blasterforum.com/do-yourself-20/build-use-leakdown-tester-10663/
contact slickerthanyou on here, he builds and sales them
You said when you got it there was a hole in the piston, was this caused by detonation from a lean fuel mix caused by an air leak? The symptoms all point to an air leak somewhere.
Do a leak down test, as awk says runaway points to an air leak!
Do a leak down test, as awk says runaway points to an air leak!
