realmenride50s
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hay guy just wanted to no if u can put a lifan 150 head on a jailin125 estart
thanks adam
thanks adam
lifan head
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headsmess
Miniriders OG
got the top cover plates off of both? check the stud spacing. thats the only issue you should have.
Cactus Jack
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Yes it'll fit but the loss of compression from the bigger combustion chamber will make your Jialing 125 "easy start" motor even MORE easy to start ... LOL ...
You'd need to make sure your engine has a domed top piston with the correct shaped valve reliefs to clear the bigger valves and higher lift of the 150 cam and you'd have to get a 32 toothed cam sprocket to maintain a 2 to 1 ratio with your crank ... The Jialing cam uses a 32 tooth cam sprocket to go with the 16 toothed sprocket on the crank ... Lifan 140/150 engines usually run a 14 toothed crank sprocket and a 28 toothed cam sprocket to go with it ... 28/16 = bend , kerrrrunch , tinkle , tinkle ....
You'd need to make sure your engine has a domed top piston with the correct shaped valve reliefs to clear the bigger valves and higher lift of the 150 cam and you'd have to get a 32 toothed cam sprocket to maintain a 2 to 1 ratio with your crank ... The Jialing cam uses a 32 tooth cam sprocket to go with the 16 toothed sprocket on the crank ... Lifan 140/150 engines usually run a 14 toothed crank sprocket and a 28 toothed cam sprocket to go with it ... 28/16 = bend , kerrrrunch , tinkle , tinkle ....
realmenride50s
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the cam spockets are the same both are 32
piston hit the valves do u no were i can get a piston to suit or big bore kit
piston hit the valves do u no were i can get a piston to suit or big bore kit
Cactus Jack
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A YX140 piston / cylinder should fit ... They're made to work with a big valve head ... Your engine "should" have a piston with a 13 mm pin but it's best to actually check yours first ... The valves mightn't hit your stock piston if it's flat or dished ... just do a clay check ...
A few possibly suitable pistons ... but you'd need to get your cylinder bored and honed ...
NEW 54MM HIGH COMPRESSION PISTON KIT, 13MM PISTON PIN - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 15-Aug-09 16:59:02 AEST)
NEW 56MM PISTON KIT, 13MM PISTON PIN - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 15-Aug-09 17:03:04 AEST)
You can buy a BBK at a good price off this guy :
NEW 146CC TB BIG BORE KIT FITS JIALING 125CC YX 140CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 20-Jul-09 19:30:00 AEST)
Hmmm ... I had assumed that LF 150's ran the same cam sprockets as the LF 140's ... I'll have to get the cam cover off my LF 150 and take a look ...
A few possibly suitable pistons ... but you'd need to get your cylinder bored and honed ...
NEW 54MM HIGH COMPRESSION PISTON KIT, 13MM PISTON PIN - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 15-Aug-09 16:59:02 AEST)
NEW 56MM PISTON KIT, 13MM PISTON PIN - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 15-Aug-09 17:03:04 AEST)
You can buy a BBK at a good price off this guy :
NEW 146CC TB BIG BORE KIT FITS JIALING 125CC YX 140CC - eBay Other Makes, Bike Parts, Motorcycle Parts, Accessories, Cars, Bikes, Boats. (end time 20-Jul-09 19:30:00 AEST)
Hmmm ... I had assumed that LF 150's ran the same cam sprockets as the LF 140's ... I'll have to get the cam cover off my LF 150 and take a look ...
china boy788
Well-Known Member
wats a clay check??
headsmess
Miniriders OG
grab a piece of modelling clay, plasticine, playdoh, oil and flour etc.
spread an even 2mm layer over most of the piston crown, reassemble engine, then VERY GENTLY BY HAND turn the engine over a few times, dont force it if it doesnt turn over easily.
disassemble, and check that valves arent cutting through the "clay"
you want about 1mm of clearance. you may be using the dremel to increase the valve relief on the piston slightly.... overdo it and youll end up with a hole in the piston....
why a mm of clearance? cus when the engines running, on the exhaust stroke the pistons inertia takes up any slack in the bearings.... so what seemed ok with the clay test is not always ok when running...trust me, i found that out the hard way
now waiting for a new piston i didnt hit the valves, i hit the head itself....oops.... and had maybe 1/4mm clearance with the clay test...
tip...dont modify engines unless youre willing to have the odd f***up, lol
(stop that laughing, jack)
i still feel akunar is the best source of pistons, if you know your dimensions already, and after something that isnt "standard"...they seem to have the most comprehensive list of sizes... wrist pin diameter, deck height, domeheight and bore....the most important dimensions that noone else seems to list as thoroughly...
spread an even 2mm layer over most of the piston crown, reassemble engine, then VERY GENTLY BY HAND turn the engine over a few times, dont force it if it doesnt turn over easily.
disassemble, and check that valves arent cutting through the "clay"
you want about 1mm of clearance. you may be using the dremel to increase the valve relief on the piston slightly.... overdo it and youll end up with a hole in the piston....
why a mm of clearance? cus when the engines running, on the exhaust stroke the pistons inertia takes up any slack in the bearings.... so what seemed ok with the clay test is not always ok when running...trust me, i found that out the hard way
now waiting for a new piston i didnt hit the valves, i hit the head itself....oops.... and had maybe 1/4mm clearance with the clay test...tip...dont modify engines unless youre willing to have the odd f***up, lol
(stop that laughing, jack
)i still feel akunar is the best source of pistons, if you know your dimensions already, and after something that isnt "standard"...they seem to have the most comprehensive list of sizes... wrist pin diameter, deck height, domeheight and bore....the most important dimensions that noone else seems to list as thoroughly...
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Cactus Jack
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I actually typed Akunar but removed it because the 56 mm domed 13 mm pin piston LOOKS like it's an Akunar piston ...
Yes you have to check for bearing wear and play plus the overall condition before you go modifying a used engine ...
Alloy conrods need a minimum of 60 thou piston to deck clearance even IF the crank and bearings are perfect ... Aluminium is elastic so the rod elongates as the engine revs ... then returns back to size as the revs drop ... After a while they stay stretched and have to be replaced ... Top fuel racers replace their rods after only a few runs ... Drag racers run alloy rods because they act like a dolly to absorb shock to the bearings ... You can actually blow an engine up by fitting aftermarket steel rods because they're too stiff which causes the bearings to get hammered ...
As for piston to valve clearance ... you need it because the valves can float as the engine revs higher ... Especially under no load conditions such as when you miss a gear or rev high in neutral ... Float is when the valves go progressively further than the lobes are lifting them ... Lightening the rocker arms , fitting stronger valve springs , lighter valves and retainers (titanium) reduces inertia and the tendency for valves to float ...
Yes you have to check for bearing wear and play plus the overall condition before you go modifying a used engine ...
Alloy conrods need a minimum of 60 thou piston to deck clearance even IF the crank and bearings are perfect ... Aluminium is elastic so the rod elongates as the engine revs ... then returns back to size as the revs drop ... After a while they stay stretched and have to be replaced ... Top fuel racers replace their rods after only a few runs ... Drag racers run alloy rods because they act like a dolly to absorb shock to the bearings ... You can actually blow an engine up by fitting aftermarket steel rods because they're too stiff which causes the bearings to get hammered ...
As for piston to valve clearance ... you need it because the valves can float as the engine revs higher ... Especially under no load conditions such as when you miss a gear or rev high in neutral ... Float is when the valves go progressively further than the lobes are lifting them ... Lightening the rocker arms , fitting stronger valve springs , lighter valves and retainers (titanium) reduces inertia and the tendency for valves to float ...
