This is my first 2 cycle build. I bought the machine last year and it had a lean burndown last year summer when my 300 pd friend rode it hard and through many puddles. So I found this board and I took everyone's advice on what combination to build.
I took it up north in October in 50 degree weather. I had a 55 pilot and a 160 main. It made great power from zero to 1/3 throttle. After 1/3 throttle it doesn't keep pulling, it leveled off. When I got to the railroad tracks I got it up into 6th and tried to get some top speed. It seized up. I let it sit a minute and it fired right back up. It did that three times that weekend. I tore it down and it had a multipoint siezer. So the engine builder was kind enough to warranty the work. He brought the cylinder to piston clearance from .002 to .004. I got it back all together a few months ago and I took it out on the ice in 18 degree weather after being properly broke in. I started running it a little hard and it seized once again with the bigger clearance. I talked with my local machinist and he was thinking that I was running way to lean on the main jet. So I got sizes 180,190,200 and 205. I took it out yesterday in 35 degree weather on the frozen lake. I tried the biggest jet first. It fell on its face after half throttle and bogged. I worked my way down to 180 with the same results, the bog just got a little lighter. So I put my 160 back in. It didn't bog after half throttle but it just doesn't pull at all. It levels off after 1/4 throttle. The thing pulls real hard up to 1/4 throttle and thats it. I had my gps and all I could get is 56 mph at the most and this was at 1/4 throttle. After changing jets a few times I notice after a few hard runs that I had crankcase oil coming out of the vent tube. Perhaps I have bad crank seals. I did a leak down test after the first rebuild but I have not since then.
I think I'm still to rich on the main and I'm getting a lean condition at half throttle from leaking seals. They are new seals, but I've seen new parts fail in the past.
I'm getting very frustrated at this machine. I've spent so much time and $ on it to have it not much faster then stock. My neighbor a few blocks away has a big bore blaster and he can do 91 mph with 14/38 sprockets WTF!
Stock piston
First Wiseco
First Wiseco
I took it up north in October in 50 degree weather. I had a 55 pilot and a 160 main. It made great power from zero to 1/3 throttle. After 1/3 throttle it doesn't keep pulling, it leveled off. When I got to the railroad tracks I got it up into 6th and tried to get some top speed. It seized up. I let it sit a minute and it fired right back up. It did that three times that weekend. I tore it down and it had a multipoint siezer. So the engine builder was kind enough to warranty the work. He brought the cylinder to piston clearance from .002 to .004. I got it back all together a few months ago and I took it out on the ice in 18 degree weather after being properly broke in. I started running it a little hard and it seized once again with the bigger clearance. I talked with my local machinist and he was thinking that I was running way to lean on the main jet. So I got sizes 180,190,200 and 205. I took it out yesterday in 35 degree weather on the frozen lake. I tried the biggest jet first. It fell on its face after half throttle and bogged. I worked my way down to 180 with the same results, the bog just got a little lighter. So I put my 160 back in. It didn't bog after half throttle but it just doesn't pull at all. It levels off after 1/4 throttle. The thing pulls real hard up to 1/4 throttle and thats it. I had my gps and all I could get is 56 mph at the most and this was at 1/4 throttle. After changing jets a few times I notice after a few hard runs that I had crankcase oil coming out of the vent tube. Perhaps I have bad crank seals. I did a leak down test after the first rebuild but I have not since then.
I think I'm still to rich on the main and I'm getting a lean condition at half throttle from leaking seals. They are new seals, but I've seen new parts fail in the past.
I'm getting very frustrated at this machine. I've spent so much time and $ on it to have it not much faster then stock. My neighbor a few blocks away has a big bore blaster and he can do 91 mph with 14/38 sprockets WTF!
Stock piston
First Wiseco
First Wiseco
If you have no leaks, the carb & spark are good it might be worth checking the pipe for obstructions. Mine was just dumb but mice can do it too.
