Sun May 30, 2021 12:15 pm

Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
 
Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
Sun May 30, 2021 12:15 pm linkquote
He needs a new piston or I need better reading glasses!
Sun May 30, 2021 12:17 pm

Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
 
Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
Sun May 30, 2021 12:17 pm linkquote
The piston had some marks on it but nothing serious. I used wd40 with all the honing and sanding, took 1500 grit paper to the piston. Now the rings have something going on with them. Both rings had a rough spot, the lower ring is the worse where a thin chunk is missing. The chip lined up with the wear marks on the cylinder. I also tried to sand the rings but as they are hardened metal only the burs were removed. Get some new rings?


Piston before


Piston after


Lower ring with a chip

Sun May 30, 2021 12:26 pm

Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
 
Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
Sun May 30, 2021 12:26 pm linkquote
Isn't the piston head dented?
Sun May 30, 2021 3:06 pm

Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
 
Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
Sun May 30, 2021 3:06 pm linkquote
Ray8 wrote:
Isn't the piston head dented?
the piston was more or less scuffed- no denting or worn channel. The 1500 sand paper polished up the scuff pretty smooth but still has thin scratches and discoloration due to temperature I think.
Ray8 wrote:
He needs a new piston or I need better reading glasses!
What makes you feel I need a new piston? I don't know the brand, perhaps it is cheap and is more susceptible to heat expansion?
Sun May 30, 2021 4:22 pm

Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4646
Location: San Diego, CA
 
Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4646
Location: San Diego, CA
Sun May 30, 2021 4:22 pm linkquote
New rings and a hone at minimum
Sun May 30, 2021 4:33 pm

Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4646
Location: San Diego, CA
 
Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4646
Location: San Diego, CA
Sun May 30, 2021 4:33 pm linkquote
Check ring gap on new rings and piston to bore clearance too
Sun May 30, 2021 4:56 pm

Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3319
Location: Nashville
 
Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3319
Location: Nashville
Sun May 30, 2021 4:56 pm linkquote
The piston and cylinder will be fine with new rings. Just be sure to check the gap. You'll need a set of feeler gauges for that, but those will be cheaper than the rings.
Sun May 30, 2021 6:16 pm

Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
 
Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 131
Location: Los Angeles
Sun May 30, 2021 6:16 pm linkquote
This



Mon May 31, 2021 12:07 pm

Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
 
Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
Mon May 31, 2021 12:07 pm linkquote
Ah, no the piston is not concave the middle, it just looks that way with all the residual oil from when I was messing with the mixture screw in hopes to give a little more fuel...all it did was put too make it run poor and stall.
Tue Jun 01, 2021 8:20 pm

Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
 
Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
Tue Jun 01, 2021 8:20 pm linkquote
Guys- I need some help on piston rings. I don't know the exact size I should be getting. I measured the piston and cylinder we are looking at approx. 56.80mm diameter for both. The piston ring channel is 2.45mm... there is clearance as I tested the piston in the cylinder and it moves freely.

My options are 57.0mm, 57.2mm and goes up by .2... I am thinking 57.0mm?
Tue Jun 08, 2021 6:59 pm

Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
 
Hooked
'75 VBC Super
Joined: 05 Oct 2013
Posts: 124
Location: Santa Cruz, CA
Tue Jun 08, 2021 6:59 pm linkquote
Spent this weekend getting the timing sorted. I still haven't adjusted the stator as I didn't have a timing gun.

Huge shout out to SoCalGuy for providing me detailed instructions on how to set the timing.

I also received the temperature reader and will get that installed. I guess the only way to check if I will get a seize again is by trial and error?



Tue Jun 15, 2021 6:27 pm

Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 4045
Location: That bushfire place
 
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 4045
Location: That bushfire place
Tue Jun 15, 2021 6:27 pm linkquote
I didn't have time to read everything l but 102 main is tiny ... get a 10-pack of jets, then you can play. Even if the only mod is a drilled carb filter it would become too small.

BTW: "I have always avoided messing with jets because to me it seems like some strange voodoo that i didn't rightly understand. I guess it is always a good time to learn..."
We have a Strange Voodoo here!
Tue Jun 15, 2021 6:31 pm

Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 4045
Location: That bushfire place
 
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 4045
Location: That bushfire place
Tue Jun 15, 2021 6:31 pm linkquote
Ray8 wrote:
Best translation I could find is "all balls."
Makes sense.
You're about right.... "riding balls out" could also work.
Speedy has 3 lines written on the throttle; "fettlin", "knobbin", "brokin" (, which just in case you thought I am unable to spell... "broken", but kept in line with the "in" category)
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