Posts
85
Joined
1/21/2015
Location
Canton, GA
US
Try to make this short
Bought a 16 350sxf a couple months ago not sure on how many hours but I'd guess 60ish. Stripped it to the frame regreased everything changed all the fluids and bearings. I've put 10 hours on it since with no issues.
First race last night. Had a hard time starting the bike in the morning before we left, never had any issue before. Got to the track unloaded and the battery died on first attempt. Got a push start, fired right up and ran fine. Let the bike run on the stand for a few minutes while I finished getting gear on to hopefully charge up the battery. Got on went to the line where I continued let it idle until they let us go (maybe another 5 mins). Right before taking off I noticed a few Puffs of white smoke float up from the radiator over the gas tank. Thought maybe from it sitting running a little overflow Steam is all and took off. On the last lap of practice started hearing a load chattering, rattle or ticking coming from the motor the higher the RPM the louder faster the chatter seems to be.
Turned it off and on a few times, no change (battery charged now). After sitting for an hour and cooling down I started it before loading it up and no noticable nosies coming from the bike at all. Took everything in me not to just race it but I didn't.
Any opinions or advice world be greatly appreciated. Grew up on 2 strokes and am decent with a wrench. Just not very knowledgeable on thumpers. Where do I start?
Bought a 16 350sxf a couple months ago not sure on how many hours but I'd guess 60ish. Stripped it to the frame regreased everything changed all the fluids and bearings. I've put 10 hours on it since with no issues.
First race last night. Had a hard time starting the bike in the morning before we left, never had any issue before. Got to the track unloaded and the battery died on first attempt. Got a push start, fired right up and ran fine. Let the bike run on the stand for a few minutes while I finished getting gear on to hopefully charge up the battery. Got on went to the line where I continued let it idle until they let us go (maybe another 5 mins). Right before taking off I noticed a few Puffs of white smoke float up from the radiator over the gas tank. Thought maybe from it sitting running a little overflow Steam is all and took off. On the last lap of practice started hearing a load chattering, rattle or ticking coming from the motor the higher the RPM the louder faster the chatter seems to be.
Turned it off and on a few times, no change (battery charged now). After sitting for an hour and cooling down I started it before loading it up and no noticable nosies coming from the bike at all. Took everything in me not to just race it but I didn't.
Any opinions or advice world be greatly appreciated. Grew up on 2 strokes and am decent with a wrench. Just not very knowledgeable on thumpers. Where do I start?
Remove it and cut open carefully with razor. Unfold.
If something is failing the metal will show up there. It is a way to start.
I cut open my filters ever time to see how things are living. The debris will be consistent when there is more time to go looking.
You can also run a magnet thru the debris to see if it is steel or aluminum.
The Shop
Yeah, I know this was self inflicted for sure and I know better than to let it sit at idle that long. Was running a little late, trying to charge the battery and get dressed before hitting the track.
Going to be a costly mistake I think but live and learn I guess.
Really just trying to figure out where to start looking for issues. Probably due for a top-end anyway so I guess I'll start there.
Also,the crankcase vent tube may be where the smoke came from. It vents into the airbox on some bikes and some folks pull it out of there and let it vent to atmosphere to avoid puking oil into the airbox.
Drained the coolant and oil with no mixture between the two.
Oil looked good with very little shavings, it was pretty much black though (rotella T6 probably 3hrs). The oil screen did have a little more shavings on the top side than I've seen in the previous two oil changes. Nothing in or on the oil filter. I don't think the amount shavings was really abnormal.
Coolant was clear (well green and transparent) and free of any debris.
Checked the valves.
Intake - factory spec .10 - .15mm
shifter side .12 somewhat snug
Brake side .11 somewhat snug
Exhaust- factory spec .13 - .18mm
Shifter side .13 tight maybe even should say very tight
Brake side .14 some drag but. 15 wouldn't go
I think I measured everything correctly. Measured between the cam lobe and black arm.
Should I go further into this thing or fill fluids and test it out?
Pit Row
If you have a shop that can do a leak down test, that will tell you how your compression is looking.
Compression tests will only tell you the compression in the cylinder. A leak down test will tell you how the engine is sealing (valves, rings, head gasket.)
Also a coolant pressure test could be performed to check and make sure the cooling system is 100% sealed. Just because you didn't see any coolant mixed, doesn't mean that it didn't get burned in the combustion process.
Post a reply to: First 18' race for me this year cut short. Engine