Page 1 of 5 123 ... LastLast
Results 1 to 15 of 63

Thread: 85mm stroke crank, need help

  1. #1
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394

    85mm crank with stock cylinder, need help

    Did a full engine repair for my SR. When putting all together and installing cylinder I noticed.... fudge. THEY SENT ME THE WRONG CRANK WITH 85MM STROKE!

    I really do not want to go all the trouble and do it all over again so:

    Do they sell some adapters that go under the cylinder, between the block and cylinder I mean?

    or

    Do I have to order a new cylinder with large capacity.

    or

    Any other ideas?
    Last edited by Ärräksä; 08-06-2017 at 10:56 AM.
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  2. #2
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    you need the spacer or return it.

    wich pipe/cyl/carb?
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

  3. #3
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    The idea was to make it complete stock. So everything is stock in the motor. I replaced crank, bearings, seals, waterpump, oilpump etc. Hope all for nothing

    Feeling quite fustrated and stupid now to be honest. But the difference between the stroke isnt that much when compared to stock so it didnt point out when I installed it. All I did notice that it was much heavier.

    Do you have an idea where do they sell them in european stores?
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  4. #4
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    ok so u got the s6 full circle crank? they have a spacer to make it work on sport cylinders. but perhaps a stock crank will be easier.

    i think but you have been here a while allready. why cant you find a scooter parts place with free shipping? what is wrong with the 5 big stores in europe?

    just start buying the topperformances parts and post here to get a second opinion. topperf has stock cranks for a decent price maybe 60eur as a guess.

    ---

    topperf has a website and they sell direct aswell.
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

  5. #5
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    Placed an order on the spacer kit. Hope it works. The crank is motoforce evolution 85mm. Dont know if its full circle.

    I would have bought the 87cc tp kit but then i would end up opening cases anyhow cause those bbk need some milling go do on the cases to make them fit.
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  6. #6
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    ok. so your putting in a new crank/bearings/seals? got the spacer....

    what else. cyl/carb/pipe/reed/clutch/vario ?

    anyway i feel like perhaps we should discuss your setup...
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

  7. #7
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    No need. All stock with complete rebuild.
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  8. #8
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    Except you cannot fit the oem exhaust with a spacer. Just not enough room in the frame when the exhaust port is moved forward. Youd get it to fit if you cut off the first dummy pipe, maybe. This I didnt predict but then again everything affects everything. Luckily I have the LV touring. That fits just fine.
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  9. #9
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    how much compression does it have. have you tested it? you should find out the psi and squish to finish and choose the correct fuel octane rating. how does all that look?
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

  10. #10
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    Quote Originally Posted by sublunacy View Post
    how much compression does it have. have you tested it? you should find out the psi and squish to finish and choose the correct fuel octane rating. how does all that look?
    I havent run it yet. I had couple of different size of gaskets and the squish is at the level that no way it will hit the head = piston lower than stock on highest position. All tho I felt that the kickstart felt quite a lot harder to move with hand when I tried it after I installed vario cover to make sure it was fine. I do not have a compression tester but nex time I get a day off Ill try to start it, after Im perfectly sure that the oil lines bleed.

    I put in a 56 main jet. Stock everything except removed vario ring and leo vince touring. I even put back in the brass restrictor in the carb. Prob. too lean. May need to rejet to 63 or something like that. At least when the brass restrictor was off and bbk was still on that was the perfect size.
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  11. #11
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    Well everything is put together now but theres a slight problem.... it wont start. Doesnt even promise.

    It shows spark but i changed the plug anyway. Gas comes to carb. I even tried removing airbox and injected gas through carb but nothing happens.

    Im starting to get a feeling that the longer crank has somerhing to do with this all tho what could have changed? Stroke is the same and so is the ignition.

    I can feel that the compression is higher than stock or 70cc by kicking the kickstart. Why. Makes no sense.

    Maybe something wrong with reeds?
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  12. #12
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    new crank main bearings will be stiff. beyond that it should start.

    ----
    secondary compression should be 110-125psi or it needs a change in base gasket thickness.

    primary compression cant be tested untill its running. if the peak power is to high or to low in rpms then the primary compression needs to be adjusted with reed spacers
    ----
    then it could be great. maybe better or maybe a little worse than stock< but nothing wrong with the setup as a guess. the increase in case volume will be offset by the high primary comp crank.
    --------------
    so in a few words it should start up. i think you better look at the compression but i assume it would start anyway.
    ~~~~
    i think you should get the matching cylinder if you run out of patience. in the end it makes no sense to put a hpc crank with a stock cylinder. the long rod changes only two little things - testing being the critical factor.
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

  13. #13
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    I would change back to stock crank but i didnt want to split the engine again when i noticed it was not stock size.

    I agree. Engines want to start but this doesnt. Imo i smell too little gas when cranking. No matter how long i kick or estart it wont fuel the plug.

    I pulled off the gas line and it drips. And as i mentioned before a direct splash to the intake manifold would not result even as a try. So im not sure im getting fuel beyond intake. Could it be it wont reach cylinder?
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  14. #14
    apriliaforum Junkie
    Join Date
    Jan 2005
    Location
    Finland
    Posts
    394
    BTW. could I drill start the motor? Battery is now dead and recharging.

    Should it be done from the vario site? Take everything away from the crankshaft and spin the heck out of it?
    Aprilia SR 50 R Factory 2009 Silver Crowd
    Aprilia SR 50 2008 Silver Crowd
    Aprilia RS 50 2003 SBK Replica

  15. #15
    apriliaforum expert
    Join Date
    Jul 2015
    Location
    ontario
    Posts
    891
    if you lose patience. setup a fully stock 50cc with a lv touring pipe then get a sport 70cc cylinder. keep the revs at 8-9000rpm for peak power all the way to 50-60mph. which carb do you have?
    --- diploma for engine repair in 2012 ---

    derbi bullet 2006 - piaggio AC - malossi T.C. half - custom GPS dash - TPR 70CC - topperf crank - vl13 reed and spacer- yamaha rt180 kickstand - giannelli shotV4 - phbg 21mm - doppler mesh top venturi filter

    complete wtp volta bmx 2012 - sanko seamless japanese cromoly heat treated and blue printed frame - 21lbs

    1992 lt250r suzuki quadracer - maier plastics -chromed shearer pipe - chromed works suspension - ++++++++ - 220lbs

    previous vehicles - subaru legacy turbo 1991 - mazda mx6 turbo 1990.

Page 1 of 5 123 ... LastLast

Similar Threads

  1. Do long stroke cranks need case work am6
    By Sketchytom in forum RS50 Technical
    Replies: 13
    Last Post: 09-05-2015, 12:33 AM
  2. Need help.. 2 stroke 50cc scooter
    By windy in forum General Motorcycle Talk
    Replies: 14
    Last Post: 01-31-2014, 12:21 PM
  3. relay,starter, or ?, need HELP!!!! Wont crank!
    By dragon in forum RSV Tuono, Tuono R, Tuono Racing, and Tuono Factory (2002-2005)
    Replies: 29
    Last Post: 03-09-2012, 10:08 PM
  4. Need help bad...Tuono won't crank
    By dragon in forum RSV Tuono, Tuono R, Tuono Racing, and Tuono Factory (2002-2005)
    Replies: 9
    Last Post: 06-29-2010, 10:24 AM
  5. crank instakation, need help!
    By josho44 in forum RS50 Technical
    Replies: 4
    Last Post: 05-19-2003, 08:08 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •