mk1 t5 tuning

ive fitted a malossi kit to my t5 engine aswel as 21 tooth clutch gear,26 auto lube carb, nk l/hand side exhaust from authur francis,(uk),changed the main jet to a 120,
what i need to know is should i changed the mixer jet to a Be5 , or leave the be4 in ,& do i need to alter the timing, im useing the ngk iridium b8 plug, would it also be worth polishing the inside of the complete caseings like the lml,s have to aid gas flow ,or is it a waist of time, ive opend up the cylinder head so the piston do hit on full revs,the scoot is hitting just under 80mph flat out (vespa speedo)so it could be 75 . im eating cruciforms every 3 months , (must b my rideing style)!!!

Diablo is right with the spark plug ,b9es it must be , if they did a 10 or 11 i would use them myself but they don’t. T5’s seem to go throu plugs for a past time, i buy them by the box. Is it me or do fancy plugs like splitfire and the irdium or race rated plug last no longer than standard ones. I remember buying a splitfire for £8 only to last one day. On the cruciforms thing it may be worth checking the cush drive springs as they also seem to be eaten by T5’s. There job is to take the shock and force out of gear changes.

hope this helps. Mark.

If its really eating plugs try B9eG. Thats what a lot of crossers use. If you don’y use them they eat plugs as well.

Hi BE5 is leaner than BE4 . I’ve always kept BE4 no problem. T5s should always run B9ES plugs or equivalent. Polishing the casings is probably not worth the effort but gas flowing the crank works (but still not much). If your going through cruciforms is your gearbox shimmed and also I always use genuine selector boxes. 80mph is not unreasonable bit if you have a mk1 and the rev counter works go on the scooterhelp website and work out your top speed from this. Did you increase the volume of the head as well as the squish diameter? This will cause problems if you haven’t. Hope this all helps;D

thanks for the replies diablo n mark ill order new cush drive springs & fit them aswel as a cruciform when i break up before chrimbo, the plug im useing ngk iridium BR8 EIX ,they lasting me 3 months useing the scooter every day going to & from work plus the uk rallies & lancashire alliance ride outs, the standard plugs used to last me 2 weeks,would i gain anything by lightening the flywheel,
just to clear it , ive got a mk1 t5 engine in my disc 02 frame,
i sold my t5 frame on ebay because of the rust & the disc frame n forks came up cheaper then a respray,some advice on the conti zippy tyres i got from lythgoe in bolton,me & a mate walked in & got a deal on 6 tyres =£16;00 each coz we bought 6 instead of just 1,always worth blagging,