Ruined big bore kit I think
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Ruined big bore kit I think
I think I may have ruined my new bore kit!!I bought a bigger jet and Installed it when putting the new cyl kit in.Only went up one size on the jet which it appears was a mistake.Took the scoot for a drive and and then died.Thought at first I could of had soemthing witht he fuel line came losse or soemthing electrical.After sitting a few minutes got it started and got it home.Was not sure what was wrong.Moved the needle clip down to botttom to richen it up and then took another ride.It went further this time before shutting off again.Was able to nurse it home for 1/4 mile.Pulled the muffler and saw scoring on the psiton.Pulled the new cylinder off and found the cylinder wall scored near the exhaust port.Made me sick.I may just have to try a quick hone and live with it if it will run.Not sure.Talked to a a scooter shop and said it may stil run?
85' Aero
Re: Ruined big bore kit I think
Lots of time extra oil in the gas will keep this from happening. Once a piston is scored in usually means the rings are stuck and until you pull the jug, you don't know. If the rings are stuck you need a new piston and rings and at least an acid job to remove the aluminum from the cylinder and then a hone job. It is irresponsible for the shop to tell you it will run that way. It might run, but not right.
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Re: Ruined big bore kit I think
So what size bore? what size carb+ gear ratio, only then can i dog you out then educate you
some people dream of speed, i own your dreams!
Re: Ruined big bore kit I think
Stock carb with #85 jet.Stock air box.Stock gears, not sure what the ratio is?The rings are not stuck.I thought I had done enough research on this site but I guess not.These 2 strokes are alot more touchy than a 4 stroke and I guess I am not the first person to do this.The thing is how can you deternine the jet size unless you ride the thing.Experience is everthing !!I may just hone my OEM cyl. and put that back on?
85' Aero
Re: Ruined big bore kit I think
Did you do any porting on the new jug? If its too much the ring could have been catching in the exhaust port.
Lambretta TV-175 (wish I'd never sold it!)
2005 Vento Phantom R4i 125cc (stolen)
1986 Yamaha XC180 Riva
1985 Honda CH150D Elite
1988 Honda SA50 LX Elite
1989 Honda SB50
2007 iScooter 150cc
2006 Roketa 150cc
2006 TNG Venice 50cc
2005 Vento Phantom R4i 125cc (stolen)
1986 Yamaha XC180 Riva
1985 Honda CH150D Elite
1988 Honda SA50 LX Elite
1989 Honda SB50
2007 iScooter 150cc
2006 Roketa 150cc
2006 TNG Venice 50cc
- Wheelman-111
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Re: Ruined big bore kit I think
Greetings:
JoeWeir1 axt:
1. Buy and install a CHT gauge.
2. If it starts but barely runs, put in a smaller jet
3. If it starts and immediately runs well, install a larger jet right away.
4. Keep it well on the fat side of jetting until break-in is completed.
5. Take small steps in jetting down, and keep an eye on that CHT.
A soft seize or two won't hurt anything as long as compression remains good. Sometimes it's best not to look.
JoeWeir1 axt:
Ah, excellent question! My suggestions:The thing is how can you deternine the jet size unless you ride the thing.Experience is everthing !!I may just hone my OEM cyl. and put that back on?
1. Buy and install a CHT gauge.
2. If it starts but barely runs, put in a smaller jet
3. If it starts and immediately runs well, install a larger jet right away.
4. Keep it well on the fat side of jetting until break-in is completed.
5. Take small steps in jetting down, and keep an eye on that CHT.
A soft seize or two won't hurt anything as long as compression remains good. Sometimes it's best not to look.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: Ruined big bore kit I think
was anything done with the airbox? mine ran like crap til i opened the air box. which brings me to this question. would removing the lid and finding say a rubber strap to hold in the stock filter make it work like a free flow? after my break in im running i believe to be 88 jet and the stock oil pump with 90:1 premix. 5...1/2" holes drilled into the top of stock air box lid.
1986 honda spree(silver fox)
BBK
85 head
SB50 intake
SB50 reeds
taz gears
2.75X10 tires
2000 honda elite S
prodigy vari
2k grabber clutch springs
9:1 gears
jdm tail lite
1982 suzuki FA50
BBK
85 head
SB50 intake
SB50 reeds
taz gears
2.75X10 tires
2000 honda elite S
prodigy vari
2k grabber clutch springs
9:1 gears
jdm tail lite
1982 suzuki FA50
Re: Ruined big bore kit I think
I thought going to a bigger jet is making the mixture richer? I keep hearing that after installing the bbk you need either to put holes in the stock airbox or put on a free flow pod filter. Not doing this will cause poor running issues.joeweir1 wrote:I think I may have ruined my new bore kit!!I bought a bigger jet and Installed it when putting the new cyl kit in.Only went up one size on the jet which it appears was a mistake.
Post pictures of the piston and cylinder that your calling damage.
Re: Ruined big bore kit I think
thanks for all the input.So should I be running premix in every tank of gas?I was told to add maybe a 1/4 ounce of oil to my first tank.Also, would you say a 90 jet would be large enough?I was told after the fact to go 2 sizes over the original which was a #80.I thought the #85 would have been enough.
85' Aero