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Post by lain on Jun 13, 2015 5:01:07 GMT -5
I just turned the flywheel in forward rotation until I was sure oil was flowing. I don't like the idea of running with an open cover, too high chance debris or litter (this is Boston) will fly in and I won't be fast enough to remove before it gets thrown down the chain.
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FFWWAOOOMP!
by: geh3333 - Jun 13, 2015 6:37:59 GMT -5
via mobile
Post by geh3333 on Jun 13, 2015 6:37:59 GMT -5
I just turned the flywheel in forward rotation until I was sure oil was flowing. I don't like the idea of running with an open cover, too high chance debris or litter (this is Boston) will fly in and I won't be fast enough to remove before it gets thrown down the chain. I couldn't get my pump started until I cranked her over. What you could do is ,hit the kill switch and crank her over . that way she won't start but it will crank over enough so that you should be able to see the oil being pumped. |
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FFWWAOOOMP!
by: mrpalmetto - Jun 13, 2015 16:34:04 GMT -5
Post by mrpalmetto on Jun 13, 2015 16:34:04 GMT -5
Could you comment on your temp gauge, where u got it and how easy is it to install?
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Post by lain on Jun 13, 2015 17:38:43 GMT -5
Finally got to checking this scoot. I took the shroud off and immediately found the cause of the loss of compression. It seems the paper base head gasket had somehow pushed out of the engine and is sitting around the base in pieces, the top head gasket had some pieces blown out but not nearly as bad. I have no idea what caused this but I know this is why my engine has low compression.
I'm going to replace the gaskets. If I never take the piston out of the jug then I will not have to rehone and get new rings right? I'm thinking of just clipping the piston to the skirt and removing the piston G clips.
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FFWWAOOOMP!
by: pistonguy - Jun 13, 2015 17:54:53 GMT -5
Post by pistonguy on Jun 13, 2015 17:54:53 GMT -5
Never Ever Reuse the Circlips!
I don't care if you've done it in the past, just done do it again
And when you replace, the opened end needs to be at 12 and 6 O'Clock.
No, just because you removed the piston doesn't mean you have to replace the ring and hone.
Just because you removed the Piston doesn't mean you have to Hone.
If you remove the Rings may be another issue.
I can't see your cylinder so I can't make a recommendation on it.
A Ball/Dingleberry Hone. or
I prefer A Nylon Soft Hone Brush. This is the Hot setup.
Do not want to remove any material just break the glaze and put a slight Cross hatch pattern.
Best Of Luck!
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FFWWAOOOMP!
by: geh3333 - Jun 13, 2015 20:01:27 GMT -5
via mobile
Post by geh3333 on Jun 13, 2015 20:01:27 GMT -5
If you can get the piston to stay in the cylinder you should be fine. Everyone I ever talked with about removing the piston from the cylinder said you must hone and use new rings. Yes you can take the chance , but others on the site found out for themselves , that usually doesn't work. The rings seat into a certain position during break in. So you must rehone and yes new rings if the piston is removed from the çylinder. If I'm not mistaken , Lain , didn't this happen to you before ? Or was it someone else ?
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Post by lain on Jun 13, 2015 21:05:47 GMT -5
Something similar happened before. There was debris between the base and head when I installed the BBK the first time. It soon caused holes to appear, but this is different. This time instead of having holes my gaskets got out of between the blocks... Vibration?
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Post by lain on Jun 13, 2015 22:00:53 GMT -5
Never Ever Reuse the Circlips! I don't care if you've done it in the past, just done do it again And when you replace, the opened end needs to be at 12 and 6 O'Clock. No, just because you removed the piston doesn't mean you have to replace the ring and hone. Just because you removed the Piston doesn't mean you have to Hone. If you remove the Rings may be another issue. I can't see your cylinder so I can't make a recommendation on it. A Ball/Dingleberry Hone. or I prefer A Nylon Soft Hone Brush. This is the Hot setup. Do not want to remove any material just break the glaze and put a slight Cross hatch pattern. Best Of Luck! I have never reused the G clips before, good to know it's not good before trying. I'm a little confused, everyone says to rehone and get new rings. I actually have a set I forgot I purchased extra a long time ago so I might just do it anyways. I've reused entire topends including gaskets before with pure stock 50ccs and have no issues so far, I tried to reuse a gasket once with this engine though (this is a 139qmb with a 50mm BBK) and it didn't work for even an hour. My guess is higher cc bores require TLC. |
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Post by cyborg on Jun 13, 2015 23:37:20 GMT -5
Cylinder studs may have taken a "set",, or stretched and you lost torque/clamping force
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FFWWAOOOMP!
by: pistonguy - Jun 14, 2015 0:42:27 GMT -5
Post by pistonguy on Jun 14, 2015 0:42:27 GMT -5
If you can get the piston to stay in the cylinder you should be fine. Everyone I ever talked with about removing the piston from the cylinder said you must hone and use new rings. Yes you can take the chance , but others on the site found out for themselves , that usually doesn't work. The rings seat into a certain position during break in. So you must rehone and yes new rings if the piston is removed from the çylinder. If I'm not mistaken , Lain , didn't this happen to you before ? Or was it someone else ? I'll touch on the briefly. I do not know how much time is on that Top End. There is no mechanical reason just because you removed the piston that warrants new ring's that would require a touch up hone. Generally since your there Many Opt for new rings and a hone for break in since its cheap. That is the Only Reason. Now removing Rings from the Used piston is another issue, Back in the day using some Different Ring Alloy Types by Expanding that used Heat Cycled Ring you could put Micro Crack's all the way around that puppy compromising Its Integrity. This is more pertaining to old Ductile Iron type rings The current Top and Second rings these days are usually made up of a Stainless alloy and are ok. But as I do not know how much time on the top end or visual inspect it myself to make a determination. I have been part of the teams that have Written the Book on this. Food for thought, If ya can hardly afford the time and money to do it correctly the first time how do you have the time and money to do it correctly the second time? ooop's, this was more than brief. |
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FFWWAOOOMP!
by: pistonguy - Jun 14, 2015 1:06:53 GMT -5
Post by pistonguy on Jun 14, 2015 1:06:53 GMT -5
Never Ever Reuse the Circlips! I don't care if you've done it in the past, just done do it again And when you replace, the opened end needs to be at 12 and 6 O'Clock. No, just because you removed the piston doesn't mean you have to replace the ring and hone. Just because you removed the Piston doesn't mean you have to Hone. If you remove the Rings may be another issue. I can't see your cylinder so I can't make a recommendation on it. A Ball/Dingleberry Hone. or I prefer A Nylon Soft Hone Brush. This is the Hot setup. Do not want to remove any material just break the glaze and put a slight Cross hatch pattern. Best Of Luck! I have never reused the G clips before, good to know it's not good before trying. I'm a little confused, everyone says to rehone and get new rings. I actually have a set I forgot I purchased extra a long time ago so I might just do it anyways. I've reused entire topends including gaskets before with pure stock 50ccs and have no issues so far, I tried to reuse a gasket once with this engine though (this is a 139qmb with a 50mm BBK) and it didn't work for even an hour. My guess is higher cc bores require TLC. Unless you have a Copper Head Gasket you can Never Reuse Gasket's Once there Crushed to the torque Point, there done. You may get away with it once or so but Taking the chance to is just not worth it,BBK had nothing to do with the Gasket failure. On the Circlips, Ive had my Riders dad's reinstall Clips in the wrong position and spit them out, Rider goes over the bars, Dad comes to me Mad, I note the clip still in place in the wrong position and have to play word games to show him what he did wrong, Also to my Horror in 99 I had a HD customer, had Joe whatever perform a bbk/ higher comp kit. Had a issue in Daytona and a Butcher Reuse the clip's, Rider makes the Sturgis trip, On the way home wearing his Poser uniform with No Helmut, Spit the clip, Wristipin walked into the Cylinder wall and the whole thing came to a Stop, HE DEAD!! I come to the office to Registered Mail that said " Congratulations you are Being Sued for 5 Million Dollars" The Product had come from my location and all in the food chain were sued, the matter was settled out of court, Now we have a Widow and Kids with no dad. Nice huh? Just not worth it. This is another area were I have been part of the team that has literally Written the Book on this. Back in the day we used what is called a Spiro Lock on Powersport Pistons, a One shot deal and Impossible to come out, Joe Garage complains for years so we went to Circlips to appease him. Customer always Right Right? Spiro Locks are used across the Board in After market Automotive. By Far the Best set-up for Normally aspirated engines, On the Turbo Charged or Supercharged Top Fuel Drag bikes I have been involved with we use a Nylon Type Button Since you have some new rings siting around probably use them, But this will require a touch up hone. Since your into these little Puppies as me invest in that Nylon Soft Hone Brush. I may be a little Blunt here but these are Basic Fundamentals/Rule O thumb that should be followed in no matter what Internal Combustion Engines you are working on. |
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FFWWAOOOMP!
by: pistonguy - Jun 14, 2015 1:15:52 GMT -5
Post by pistonguy on Jun 14, 2015 1:15:52 GMT -5
Cylinder studs may have taken a "set",, or stretched and you lost torque/clamping force Borg is correct here in that Studs/ Bolts can only be Torqued so many times. Think here, when the Matting surfaces meet the Only thing your doing is Stretching the Stud/Bolt. Once this is done a few times the Stud/Bolt cannot stretch any further and you will lose Clamping Force. We used to measure the length of SBC Rod bolts, This would show me if the Engine was Over-Revved and or the Studs were Re-used and Torqued too many times. I don't even bother anymore and just install some new ARP hardware. Again these are some fundamentals that should be followed all the time. |
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FFWWAOOOMP!
by: cyborg - Jun 14, 2015 7:18:36 GMT -5
via mobile
Post by cyborg on Jun 14, 2015 7:18:36 GMT -5
I use the buttons
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FFWWAOOOMP!
by: pistonguy - Jun 14, 2015 7:34:18 GMT -5
Post by pistonguy on Jun 14, 2015 7:34:18 GMT -5
A Man in the Know! Up Early, Must be watching Moto GP from Spain like me  Marques goes down, I think he's lost the mental edge and patience, pushing to hard, third crash so far. Lorenzo rode a nearly flawless race. |
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Post by lain on Jun 14, 2015 7:45:42 GMT -5
What about if I do not remove the circlips? Then I could just put the new rings on the piston and not worry about the clips right? I have a small cylinder hone, used it once before.
I think the rods may have been torqued too many times, they seem longer, like by a few hairs, than on my other 139qmb engines. How do I go about removing them? Can I use the rods out of another engine?
I'm really trying to work with what I have without buying anything else.
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