running in

can anyone tell me how many miles it should take for a pk50xl with a 110 kit to be run in for? done just over 200 miles and last night for first time took it up to 35 and it heat seized for a few minutes,ran fine again after.

how much would this sort of thing cost at a dealers? is it a simple job or would i need to get an expert?

thanks ozzy, i,ve been in touch with the firm that sold the kit and he has told me it needs 500miles running in and timing is fine as is but i have tried a hotter plug and it still did it so i,m hoping it just needs more running in? the guy who fitted the kit said it was very tight and it is only the cheapest kit going so made of cast iron and dont disperse heat very well so i,m gonna try running it carefully up till 500 miles then see how we go,he also said to get the best from the kit i should upgrade the gearing and get a 19/19 carb jetted to suit but i,m not thinking that far ahead yet.


cheers for all your help and advice its much appreciated

any motor cycle workshop (a proper one with greasy looking men not a bike show room that will rip you off) will check your timing with a strobe for not much, its a really quick thing to do. strobing is the only way to really check and set up your timing, anything else is just a guestimation.  you need to find out how many degrees advance it needs, the kit will have been supplied some bits of paper which will have this on, it will probably say somthing like '18degrees BTDC' (before top dead center) this means you set the spark to fire 18degrees before the piston reaches the top of it's stroke... your kit might need about 20degrees or it might need 17degrees. i have heard of people recieving their kits minus paper work?? i have also heard of people saying 17degrees is safe for running in the DR130 kits, probably similar to your kit... too much advance (ie higher number of degrees) is much more risky than to little advance; to much will cause overheating, to little will just lose you power and not much else :)

have you tried contacting a club?


P.S. you own a vespa, becoming a mechanic is part of the deal ;)

people say 500miles, but thats very conservative, i guess if you take it easy for 500 miles then it gives you more time to tweak jetting/timing etc before you rag it...... i have ran kits for about 45mins then given them hell and they've lasted ok.. its more about the quality of your build/setting up... i would have said 200miles was ample but you had a heat sieze.... thats worrying, did you up jet when you did the kit?  

Have you checked your oil pump? Make sure its working properly. You can check the oil hose going in to the carb box if it has oil in it by pulling it out and  pointing  it downwards. Oil should flow out of it immediately.

i,ve been out on it this evening and done 20 miles with no problems at all,i,ve stuck to 30 and not pushed it any harder than that,would it not happen all the time if it were an air leak or timing?or is it something that would only kick in when the engine is pushed a bit harder? i,m no mechanic so its all a bit confusing to me,i,d like to just take it somewhere and get it sorted but just dont have the cash at the moment,but thanks for all your help.

Cast Iron Kits are not inferior compared to those kits with Nikasil bore.

With your case, I will assume your engine has been built the proper way, making sure the piston is alligned with the bore when installing the kit. Also, did your tuner "TDC" the piston in relation to your ignition timing? My friends bike was plagued with engine seizure since the day it was assembled with a Malossi Kit. I tried setting his motor to TDC and upto now his motor runs great, no more seizure, no more overheating. Maybe you have the same case as my friends bike, have your motor checked if yours is at TDC.

hi and thanks,the guy who put on the kit who i bought it off said he upjetted for the kit,it just seems funny that i can go 20 miles not exceeding 30mph and its fine,but first time i go over it siezes and this is not flogging it,about half throttle is all its had?

Setting your engine at TDC is a simple job. You just need a Degree Wheel. I do this by removing the flywheel and cylinder head. I find TDC manually by checking the movment of the piston. When I'm satisfied with the position of the piston at TDC, I put on the Degree Wheel and set a pointer at exactly 0 degree. Then, back it off at the specified degree indicated by your Engine Kit ( 18 degrees Before Top Dead Center). After setting the piston at the specified degree, I also check the stator if its alligned with the correct timing mark. Thats it. Your done. Install the flywheel and cylinder head and start your motor.

Thanks Ozzy for the input. I appreciate it. The procedure you shared is good and very effective. I really haven't tried it yet though but I'll give it a shot soon. Maybe the bikes I've built will make more power if try this one. So far, both are in good running condition. Thanks again and more power.

With a Malossi Kit, it says 40-60 minutes of continous running. With a Polini Kit, it says 500kms. I've built 2 Polini Kits for PX150 and PX200. I've broken it in for atleast 100kms before I gave it a taste of full throttle. Making constant shifts from 1st to 3rd, raising the rpm high enough for the engine to experience it. I made sure my mixture is alright (slightly on the RICH side), and spark plug heat range is of the advise of the kit. So far, both bikes are in good Racing/Running condition.

Also, I make sure the "oil metering device"/ oil pump, if equipped, is primed before running your engine. Make sure the oil hose has no air bubbles before starting. If so, it would take a long time for the oil to reach the carb/engine causing your newly built engine to seize right away.

i,ve had a new plug in this afternoon and given it some hammer on axle stands in fourth gear,full revs and left running in fourth at low revs,the plug is looking perfect! a nice chocolate brown colour,could it be that it seized because its not run in enough or is it something else?been told allsorts today,crankcase leaking air in?carb leaking or timing out? would the scooter run so well if it was any of these?it starts and runs lovely,it goes for an hour getting up to 30mph with no probs?i,m out of ideas,ive set mixture to 1.5 turns out,spark plug colour is good,as far as i know carb was upjetted for 110 kit,been told standard timing is ok for 110 kit and it has a standard exhaust.

any ideas from anyone gratefully recieved thanks

the oil is pre mix and i,m adding a little extra also as i was advised to while running it in?


hi dawn, is your plug the same heat rating you used from the standard kit? plugs are made with different insulation properties, some 'hotter'plugs wick the heat away more than cooler plugs. if you run a plug with insufficient heat rating on a more tuned engine then the plug can't cool itself quick enough and starts to glow, when this happens the fuel/air ignites before the plug even sparks (pre-ignition/detonation/pinking), your scooter over heats and siezes...

 also your ingition might have too much advance.. it would be fine a low revs (probably run pretty well) when the cylinders not scavenging optimally, but as the revs pick up and scavenging improves, the air/fuel mix would improve in quality and the advance you have on your ignition might be too much.. the result of this would be that you piston would be trying to compress rapidly expanding gases and your bike would overheat, pink, seize......

 double check your timing with a strobe and then maybe try a hotter plug,


hmmmmm.... somthing is not right! if you've done 200miles and its nipping up, its not right, thats a fact.... are you a memeber of a club? if not try calling your local club (look in scootering) someone is always willing to help out... if a kits tight it will sound tight for maybe a few minutes not 200miles.. if its seizing after 200miles then thats not going to stop happening without somthing being fixed/altered..when he says the timing is fine as is does he mean its unaltered from the original kit? if thats the case i'd be suprised if thats ok.... what kit is it?

are you a member of the yahoo group? or the later is my forum of choice, all very helpful and knowledgable people and you'll get alot more responses than here... try posting your problem there as well... i'm pretty sure people will say its timing or an air leak..


p.s the guy is talking rubbish if he's blaming it being a cast iron barrel, this is not a super tuned machine, its probably about 4-5hp, i've had nearly 19hp from an iron barrel with out it siezing


thats all well and good if the pick up, the woodruff and the little bit on your flywheel are in exctly the right place... production tolerances allow for about 2degrees of varibility. strobing tells you when your spark actually fires, not when it should fire. you find top dead center (it important you do this right, its not whe the piston stops moving as the psiton is pretty much still for quite a few degrees, its half way between when you feel it stop and when you feel it start to desend again, mark TDC  on the cases and flyweel with a dot of tippex or something. Now measure you 17/18 whatever, degrees back anti clockwise on the casings, mark it, hook up the strobe, start your engine, shine the strobe at the fly wheel and the TDC mark on fly wheel will iluminate and tell you where its firing in relation to you 17/18 degree mark. take the flywheel off adjust, try again until right... now you have a properly timed bike :)

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