alec
Member
I have to choose between an SD stinger and a pk-80. Which engine is better? the sd kit from bikemotorkit.com has alot of upgraded stuff i guess.
PK-80 or SD stinger
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Skyliner70cc
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I got a PK80 last month that I finally got to install on a bike this weekend.
I thought they were built better; here is what I found.
1. Engine would not turn over. I took it apart and found the following:
(a) Large chunks of plastic in the crankcase.
(b) Engine missing upper wrist pin bearing (not kidding).
(c) Head studs were loose
2. Same crappy hardware that all HT engines have.
3 Intake had manufacturing flashing that partially blocked the intake. Removed it when I did some mild porting
4. Broken solder tab on magneto
5. Carb is NOT an NT carb. I have about 9 non-NT carbs in my collection...they are junk.
6. Enigine had bent fins (not quite as bad as when I buy from Boy Go Fast but I thought Pirate Cycles sold better HT stuff)
7. Crank seal behind drive gear on clutch side is torn. I'm glad I pulled the gear to install a centrifugal utch.
8. Engine kit did not come with a gear puller.
9. 48mm front engine mount spacing....had to modify commercial engine mount designed for oversized bike tube.
10. Had to grind down spacer on SBP shifter kit so 15 link 415 chain would fit the shifter engine assembly. I never had this problem before with any other engine.
It better be worth it when I fire up the engine later this week. I bought it from Pirate Cycles because the PK80 engine has reputation of being more powerful than other happy time engines and manic mechanic's pirated head design fits on te PK 80.
I thought they were built better; here is what I found.
1. Engine would not turn over. I took it apart and found the following:
(a) Large chunks of plastic in the crankcase.
(b) Engine missing upper wrist pin bearing (not kidding).
(c) Head studs were loose
2. Same crappy hardware that all HT engines have.
3 Intake had manufacturing flashing that partially blocked the intake. Removed it when I did some mild porting
4. Broken solder tab on magneto
5. Carb is NOT an NT carb. I have about 9 non-NT carbs in my collection...they are junk.
6. Enigine had bent fins (not quite as bad as when I buy from Boy Go Fast but I thought Pirate Cycles sold better HT stuff)
7. Crank seal behind drive gear on clutch side is torn. I'm glad I pulled the gear to install a centrifugal utch.
8. Engine kit did not come with a gear puller.
9. 48mm front engine mount spacing....had to modify commercial engine mount designed for oversized bike tube.
10. Had to grind down spacer on SBP shifter kit so 15 link 415 chain would fit the shifter engine assembly. I never had this problem before with any other engine.
It better be worth it when I fire up the engine later this week. I bought it from Pirate Cycles because the PK80 engine has reputation of being more powerful than other happy time engines and manic mechanic's pirated head design fits on te PK 80.
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Skyliner70cc
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I looked a the SD engine on your weblink, its nothing special or upgraded. At least the PK80 has a slant high compression head....granted the headgasket on it is about 1/2 foot thick......
alec
Member
So should I get the sd stinger or the pk? I am gonna buy a slant head for about 20 bucks if I get the sd. I havent heard anything bad of the sd's accept some dying at 500 miles because the guy didnt use synthetic oil or ran too lean or something stupid
Dude That guy is wacked !!!!! I bought a PK80 , pulled it apart and put it back together ,was perfect ! NT carb and runs great !!!!! I have pics on here ,no bent fins and such !!!! I would buy from them again and treated me good and gave me candy !!!!!
Skyliner70cc
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Yeah, I'm wacked. I've built and sold more motorized bikes in the past 7 years than you'll ever in a lifetime.
My pirate cycle PK 80 carb says NT etched on the black airfilter but if you look on the side just above the idle adjustment screw, it says WH. WH is not an NT carb......mail me postage money and I send it to you....its garbage to me and will never be used.
I'd buy a PK 80 again but I'm not very impressed, its not much different than any other crappy time engine. As for **** inside the engine, not unusual and fairly common. I was expecting to see casting sand an other **** left over from the manufacturing process but instead found plastic and a missing wrist pin roller bearing.
Hey, about 4 years ago, I got an engine from a very reputable vendor that was missing a piston ring. Stuff happens.
I'm not very worried about the problems I've found. My PK80 already has gotten a new head, new CDI, new reedvalve intake from Australia (thank you rock solid), new seals, new bearings, a dellorto clone carb, a torquer II exhaust pipe, and a shifter kit.
I'll eventually add a ceramic piston and a more aggressivly ported head later down the road.
As for the bent fin, its very odd that it is exactly the same fin that is bent on almost every boygo fast kit I've gotten in the past.
Vermhot, did you keep that very thick stock PK80 headgasket or did you put a normal thickness one in? Or do you even know what a normal thickness headgasket looks like?
My pirate cycle PK 80 carb says NT etched on the black airfilter but if you look on the side just above the idle adjustment screw, it says WH. WH is not an NT carb......mail me postage money and I send it to you....its garbage to me and will never be used.
I'd buy a PK 80 again but I'm not very impressed, its not much different than any other crappy time engine. As for **** inside the engine, not unusual and fairly common. I was expecting to see casting sand an other **** left over from the manufacturing process but instead found plastic and a missing wrist pin roller bearing.
Hey, about 4 years ago, I got an engine from a very reputable vendor that was missing a piston ring. Stuff happens.
I'm not very worried about the problems I've found. My PK80 already has gotten a new head, new CDI, new reedvalve intake from Australia (thank you rock solid), new seals, new bearings, a dellorto clone carb, a torquer II exhaust pipe, and a shifter kit.
I'll eventually add a ceramic piston and a more aggressivly ported head later down the road.
As for the bent fin, its very odd that it is exactly the same fin that is bent on almost every boygo fast kit I've gotten in the past.
Vermhot, did you keep that very thick stock PK80 headgasket or did you put a normal thickness one in? Or do you even know what a normal thickness headgasket looks like?
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alec
Member
So pk80 from piratecycles or Sd stinger from bikemotorkit? I need to know because im probably order it tomorrow
chainmaker
Member
without a doubt I would go with the PK from Pirates.
alec
Member
I just found out that I can get a grubee and a jet from piston cycles because they are located close to me. Are those better choices? I like the idea of looking at the kit before I buy it.
Lunardog
Member
Gave me candy?!?! wtf?????
