Apollo RFZ 125cc pit bike top end rebuild how to !

[@jordanevans1540]

I haven't rebuilt one of these in a long time, but, I'm currently having an issue with my timing chair going around the front sprocket and screwing back in, I'm not sure why there's not enough slack for it, any tricks or reasons for this?

[@WaldensWorld]

Line up the gear spin it back a hair with cam out one bolt in far as you can n slowly rotate flywheel while pressing gear on

[@jordanevans1540]

@@WaldensWorld thanks, but the timing chain on the bike itself was a tad short, I had to legit use a flathead and pry it to get it back on, the holes and everything wouldn't lineup, I then removed it after and just out the whole top end in my other engine and it all fits fine, it's the timing chain itself was the issue

[@bmxrider8284]

Wasup man I got a 125 rfz starts up good rides good but once it’s fully warmed up after riding it around for 30 min or so it’s starts to smoke from exhaust and I’ve noticed that there’s a air hissing sound coming from the hose that connects to the air box and crank case any idea on what that might be about

[@WaldensWorld]

Time to rebuild top end your rings are shot you got blow by into the crank case ! You need new piston n rings for sure

[@Meza-m6k]

What size piston I usually see 52mm then 54mm which one should I get I don’t got a tool to measure I might just get the 54mm

[@WaldensWorld]

Mic the cylinder if it has a longer stroke it can have a smaller piston n still be same size cc

[@user-qw3el8qd2g]

Whats the ring gap spec? I'm currently rebuilding one as well

[@WaldensWorld]

Not thicker than a finger nail is how I like them .05mm aprox

[@Stormcc_]

Hey, great info. I had question maybe you can answer. My 125cc 4 stroke spits splooge out the exhuast, white smoke and the idle jumps really high when the chokes down. Any ideas?

[@WaldensWorld]

Is it burning oil ? Is vent from engine hooked to air box ? Bad rings time for rebuild or if you have vent to box u may have carb leaking into engine n blowing oil into air box then into carb ! Idle I’d check the gaskets around the intake for cracks or leaks ! Be my first guess n thanks for watching

[@JKProductions01]

Where did u but the kit

[@WaldensWorld]

U can get a kit off eBay I had it here I tend to hoard crap ! If you need help finding it holler back

[@harleyprimmerman6061]

Where do I order this

[@WaldensWorld]

eBay you need to mic you piston buy the right size