Jasil aka Top Racing Crankshaft

  • Hello everyone

    I am currently in the process of doing a full engine rebuild for my 1999 dt125r

    So far the engine is completely open and bearings are ready to be removed.

    Now that the cylinder and cranckshaft are out of the engine, i was wondering what i would do with them.

    In this thread i will focus my attention on the cranckshaft and try to clarify some things about the aftermarket cranckshafts available on the market.

    Attention, first of all i want to say that all the cranckshafts i will present are only compatible with kickstarter models.

    At first i was going to send my cranckshaft to be rebuild and be done with it.

    Now the problem is that i dont like the idea of someone else doing this work for me if i dont trust them 100%, and i dont know anyone in my area who could do this.

    And sending the crank to germany or the uk (i live in Belgium 😛 ) would be very costly and the shipping could potentially damage the crank.

    Now i heard about those aftermarket cranks in the past and didn't really care because i never heard of the brand and got 0 trust in it, because who knows where that could come from.

    But seeing as my only options would be either very costly or uncertain kwality wise, i started searching for info on these cranks, seeing as no one really did this.

    So if you search a bit on the web you will stumble on mainly 3 different cranks



    Top racing




    Top racing is made by Jasil so they are the same thing.

    I'm not sure about Parmakit but seeing as they sell alot of stuff they dont make themselves i am fairly certain they are also Jasil made.

    So who is Jasil and what is their history and reputation.

    Jasil Has their own website called http://www.jasil.com/

    You can find info about the fabrication process and some info about their company.

    They also have a youtube channel "J.António da Silva Lda."

    The first video looks to been made with good care for detail and shows their company with the workplace and a showcase of their machines.

    To me it seems they are trying to give confidence in potential clients who dont really know them.

    They did a great job in my opinion.

    Now these guys mainly focus on scooter performance parts and dont really have alot for more then 50cc bikes.

    In 2012 Jasil introduced their products to the french market, where 50cc tuning is very popular.


    As you might know, they where faced with some hard concurence like parmakit/malossi/polini

    Now 5 years later we can assume they could have made or broke theyr reputation.

    So i went on several french forums to see what people s'opinions where.

    You migh have noticed with these type of products that not alot is needed for a company to be stamped as bad, and they need to know what they are doing to be respected by the public.

    I was happy to see that everyone had alot of praise for their crankshafts, and that you could very well see they where a quality product.

    Also i learned that Doppler (also a big name in 50cc performance parts) branded their name on Jasil products.

    So that is also a confidence boost.

    At this point there is no denying that they gained my trust.

    So then i started searching where i could buy this crank.

    You can find them on ebay and on multiple websites for price varying from 120 to even 250€ FOR THE SAME THING!!!

    Remember that top racing is branded on Jasil boxes.

    Knowing that They are manufactured in Portugal, it looked for portuguese websites that sell these cranks, and i found exactly what i wanted.


    For 125€ + 10€ shipping this is excellent.

    That is about the same price to rebuild a crank.

    So i made my order today and will report as soon as i get it.

    I may even make a tolerance test at school if i get the opportunity to see if tolerace is under the recommendation of yamaha


    First of all my apologies if there are some gramatical mistakes in the text, english is not my native language.

    what you just read are just my opinions and what i found out,if you would add something or correct me, feel free to do so.

    Maybe some people will think this subject is irrelevant but i felt the need to clarify some things about this topic because it was really frustrating to see that no one really knew anything about these cranks, and seeing as they are the only available option as a new product, it would be excellent to get a confirmation of the quality. If this post can be of help for atleast one person, it would be worth the time to write this.

    Thanks for reading.


  • Skellerns Cheltenham charge £30 to rebuild a crank, if you supply the bits. The benefits from those cranks look like they come with a forged rod. Probably the main benefit from having those crankshafts.

    I have never heard of a crank failure on DT's so stock should be good for any power gains you have in mind.

    A Top Racing crank I'd imagine is going to be more costly than sending a crank to and from a place to have rebuilt.

    I use Skellerns, as they are local to me. But the guys at PJME are two stroke experts and probably deal with people overseas more so than my local Yammy Dealer.

    I know Skellerns will ship overseas as I've needed them to in the past. So long as the parcel is well packaged, I can't imagine postage costing too much.

    It might be a whole lot cheaper than buying unnecessary components.

  • Alot of our tuners up north will work with you internationally, postage might be £25 or so.

    Interesting as a modification, but Jasil state no changes in mass, I'm still tempted with one but unless this 'Racing' style crank is lighter, you are better off having the Yamaha crank built with a forged rod, you would have to try really really very hard to blow the bottom end apart on a DTR.

    These Yamaha cranks are solid from factory, any crank will be balanced.

    Will be interesting to see a comparison.