LT 80 lacking vacuum
#1
LT 80 lacking vacuum
Hey gang,
so I was trying to improve my (and my kids) lt80 ....ha.!
I did brake cables, air filter, new intake boot, straight flo petcock and carb rebuild kit from moose.
It was running ok before but wanted to finish up the job i started. I bought it dead this summer , It was lightly seized because the oil injector had failed.
I disconnected the oil injector put in a new starter and battery, cleaned the carb and lubed the top of the piston it ran. And quite well I thought
( slightly rich I thought) but fine on 32:1 premix. It pulled me and my two kids on it at a good clip and would wheelie with just me on command.
but... I had to mess with it... I am very good at breaking things that are not broke.
anywhoo, a while back I ordered the parts I mentioned erlier for the fixes and installed them all yesterday.
after everything was put back together last night one slight touch of the starter and it purred like a kitten making popcorn.
thats good in my mind . I was super pumped that it all went schmooth.
I let it warm up, drove 10 feet and it bogged.
could not get it started again. tried for 10 min.
Pulled the carb and went to the place I thought was the most suspicious.
that little rubber o ring that came with the carb rebuild kit under the main jet.
it seemed too big and somehow not right. so after the second time i pulled carb last night , I found it restricting the size of the jet, I took it out and put a smaller o ring in its place.
I also noted that the vacuum line wasnt blocked properly so I made a good seal. checked float level with a clear tube also. seems good.
it seemed to me that the gas was not getting into the engine.
a squirt of quickstart and the engine fired right up but only for a sec.
today I learned that if I put my hand over the intake of the carb the bike will fire right up. and stay idling,
I can put the boot back on and go for a ride. So I thought I fixed it by reducing the size of the o ring and tightening up the vacuum port
. Once its warm, I can fire it up no prob. again and again
BUT If I leave it for an hour or two, it wont start unless remove the boot and I cover the intake at the carb.
Its not quite as powerful as before the rebuild but runs well once its started.
mind you its also -2 and snowing
the choke seems to work but its not enough choke to start it . I have to completely restrict airflow to build initial vacuum,
or atleast thats what I have deduced.
could leaky crank seals do this? I would have thought it wouldnt run well with leaky seals ? but it does run well, just wont start well.
should I completely remove the rubber o ring under the main jet? is that making it harder for fuel to get moving untill there is vacuum built from
a running engine? I mean its strong enough to wheelie with me on it so I would assume the compression is ok?
what are your thoughts ?
thanks in advance for taking the time to read this. '
let me know if you have any q's
cheers
Tarik
so I was trying to improve my (and my kids) lt80 ....ha.!
I did brake cables, air filter, new intake boot, straight flo petcock and carb rebuild kit from moose.
It was running ok before but wanted to finish up the job i started. I bought it dead this summer , It was lightly seized because the oil injector had failed.
I disconnected the oil injector put in a new starter and battery, cleaned the carb and lubed the top of the piston it ran. And quite well I thought
( slightly rich I thought) but fine on 32:1 premix. It pulled me and my two kids on it at a good clip and would wheelie with just me on command.
but... I had to mess with it... I am very good at breaking things that are not broke.
anywhoo, a while back I ordered the parts I mentioned erlier for the fixes and installed them all yesterday.
after everything was put back together last night one slight touch of the starter and it purred like a kitten making popcorn.
thats good in my mind . I was super pumped that it all went schmooth.
I let it warm up, drove 10 feet and it bogged.
could not get it started again. tried for 10 min.
Pulled the carb and went to the place I thought was the most suspicious.
that little rubber o ring that came with the carb rebuild kit under the main jet.
it seemed too big and somehow not right. so after the second time i pulled carb last night , I found it restricting the size of the jet, I took it out and put a smaller o ring in its place.
I also noted that the vacuum line wasnt blocked properly so I made a good seal. checked float level with a clear tube also. seems good.
it seemed to me that the gas was not getting into the engine.
a squirt of quickstart and the engine fired right up but only for a sec.
today I learned that if I put my hand over the intake of the carb the bike will fire right up. and stay idling,
I can put the boot back on and go for a ride. So I thought I fixed it by reducing the size of the o ring and tightening up the vacuum port
. Once its warm, I can fire it up no prob. again and again
BUT If I leave it for an hour or two, it wont start unless remove the boot and I cover the intake at the carb.
Its not quite as powerful as before the rebuild but runs well once its started.
mind you its also -2 and snowing
the choke seems to work but its not enough choke to start it . I have to completely restrict airflow to build initial vacuum,
or atleast thats what I have deduced.
could leaky crank seals do this? I would have thought it wouldnt run well with leaky seals ? but it does run well, just wont start well.
should I completely remove the rubber o ring under the main jet? is that making it harder for fuel to get moving untill there is vacuum built from
a running engine? I mean its strong enough to wheelie with me on it so I would assume the compression is ok?
what are your thoughts ?
thanks in advance for taking the time to read this. '
let me know if you have any q's
cheers
Tarik
#5
#6
Ya ok. Is there any cylinder and piston I can get as a kit for a reasonable price that’s decent? Just not sure who locally would bore for me.
Also I still am having a hard time accepting without compression test done cause today
I blocked the intake and it started right up and I rode it for an hr.
Had lots of get up and go and it was -5* out !
it will start right back up with starter until it gets fully cold.
Then I need to block intake again.
Still sound like low comp to you?
Also I still am having a hard time accepting without compression test done cause today
I blocked the intake and it started right up and I rode it for an hr.
Had lots of get up and go and it was -5* out !
it will start right back up with starter until it gets fully cold.
Then I need to block intake again.
Still sound like low comp to you?
#7
Trending Topics
#8
#10