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Post by Zino on Jun 2, 2020 16:31:21 GMT -5
I am at a loss how that gets broke .
Casting flaw possibly ?
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Post by dexameth on Jun 2, 2020 18:00:08 GMT -5
I am at a loss how that gets broke . Casting flaw possibly ? But in the cylinder or piston would you think? This setup has been strong for many miles... I was at a light, blipping the throttle til it turned green and made it about 2 football fields down the road and this happened. Not crazy with the throttle, not wide open, just riding like I do every day. |
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Post by 190mech on Jun 2, 2020 18:11:37 GMT -5
Dude!That sucker it FRIED!!Very lean part throttle carb setting,too much compression,advanced iggy timing can all make that happen..Do you have a CHT gauge?If not,put one on the need list...
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Post by dexameth on Jun 2, 2020 18:45:15 GMT -5
Dude!That sucker it FRIED!!Very lean part throttle carb setting,too much compression,advanced iggy timing can all make that happen..Do you have a CHT gauge?If not,put one on the need list... I've been meaning to get a CHT gauge since I first started with this thing. But... It's been fine for a while now so for it to do this all of a sudden just doesn't add up. |
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Post by 190mech on Jun 2, 2020 19:51:34 GMT -5
Wide open is safer on a piped 2stroke than cruising at part throttle,there is always a lean 'dip' in the carb at mid range,thats why lots of tuners make part throttle very rich to have a 4stroking stutter..
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Post by dexameth on Jun 2, 2020 19:55:29 GMT -5
That's the thing, I'm pretty much always wide open, then let off for a second to slow down, blipping the throttle as I do so. The time the piston blew a hole I was at like 30% throttle and ever since then I've been afraid to cruise mid-throttle.
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Post by dexameth on Jun 3, 2020 8:29:21 GMT -5
I was able to flush the case out last night the same way I did before...
1. Remove intake/reed block and gaskets
2. Remove cylinder/head/piston and gaskets
3. Rubber band around cylinder stud and then around con-rod to protect con-rod.
4. Pour gas in reed hole while spinning flywheel nut with cordless drill, waste spills out cylinder bore.
5. Blow with compress air to remove any particles.
6. Repeat 4 and 5.
I then moved on to cutting gaskets to match the cylinder ports - funny how they are all way smaller than even stock ports. By this time the sun was setting and I was getting hungry, so I put everything on hold. I'll tear into it tonight again if the weather permits. Calling for rain, so I popped on a stock cylinder/head and put the intake back on to keep anything from getting in the crankcase.
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Post by dexameth on Jun 11, 2020 10:59:10 GMT -5
So after the last catastrophe I had stripped down the engine and cleaned it out, and then couldn't touch the build for a week... was just too busy. So last night I get home and I actually had the time to pop everything together and get it installed.
Took quite a few kicks to get it fired up... I'm thinking I may have lowered the compression too much. I have a 2.2mm stroker and with the last kit I had to add 3 base gaskets and no head gasket for proper squish and port timing. This build is using a stock head, so I added three new base gaskets and even used the head gasket and turning the engine by hand it feels like it's less compression.
Once it fired up she smokes pretty good burning odd the 2t oil used during assembly. I added muffler sealant putty to the exhaust stub for a better seal. Idles great with the 28mm carb. Took a quick spin and the needle feels too rich, easy change. I'll dial in the carb this weekend when I take it to the trails haha
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