The Z155 is basically the same head. I have found that matching the ports to the gaskets makes a big difference and cleaning up the whole port with most of the work in the port floor is well worth doing. The cam sprocket has been slotted a little too and its let the engine rev a lot more with more power overall and a couple BHP gain at peak power. On the dyno the difference can be seen as just a better power curve with gains almost everywhere apart from really low RPM due to the slight change to the cam timing. But the motor is never down that low so its not really even worth worrying about.
@@QuantumMotorWorks I spent time on my motor as in the UK pit bike racing is mostly supermoto style and on tarmac. So power is all important and with dyno time on carb set up we found about 0.7bhp which is a good gain when the dyno only reads 12.2 to start off with. Now we are up close to 15bhp on that same dyno. But we have done a few things because TB heads are not legal in one of the race classes, well the roller rocker head is not at least. So we have re-profiled cam followers now, mappable digital ignition, ported head, CNC machined inlet and a much longer under engine exhaust which runs up through the swing arm, next to the shock, and out where the normal MX style exhaust would exit. The MB Factory and Ayrton Pit Bike valve retainers are safe for at least another 1000 to 1500rpm as we did drop a valve with the stock retainers and being much lighter there is now no more awful valve float at high rpm too. The only real difference between the YX160 you have and the Z155 is the closer ratio gearbox and ignition system. The rest of the motor is basically the same in performance terms. The YX has a longer stroke but it seems to still rev out the same as the limit is valve float not simply running out of RPM due to the longer stroke. If we could run the TB roller rocker heads then I know it might give us more power but the cost of that kit is just too much for a kit we cannot race with unless we run the Open class with 190 and 212cc daytona engines or Honda CRF150's with 185cc big bore kits and 85cc to 112cc two stokes . It would just be killed on track.
@@QuantumMotorWorks I have to try to keep within rules here for racing. I am only having fun myself, but I am also the UK importer for the bike brand so if someone wants to test the bike I need to let them test a bike close to one they can race. I let a guy race it a few weeks ago and just arrived at the track. he had never ridden the bike before and it started to rain as soon as he went out on slicks and we had no rain tyres with us. He finished in 3rd place on a bike he had never seen before, ridden before and in the rain on slicks, Now he wants to test the bike in the dry as he was the only guy out there on slicks all day and never finished lower than 4th. The extra RPM and not so much torque at lower RPM let him use the throttle harder. It is fun to see and engine I built do so well against some very expensive bikes and engines.
@@YAMR1M I need to make some follow up videos on my mini bike builds. Maybe in the upcoming weeks. Let me know if you ever plan on coming out to california for some riding....I'm the process of building a rental fleet, and may have some mini race bikes available.
Ive literally had the exact same thing happened to me with the same motor, I only put 3 hours on it and 95% of that was tuning so not even reving out, I honestly do think the stock Crank was just junk, timing side skipped/sheared and it totally lost spark. Was a good little motor before that
ive def considered this kit for my 110 but from what the TB head casting looks like.. I think I'll hold off. also the ports may be a bit different but far from ported. I think I'll just be modifying my own head.
So far so good. I think I have 3 hours on my meter since the overhaul. The ports are indeed not cnc or hand ported, but are casted. They are larger in diameter compared to a stock 110 cylinder head, and the valve angle is slightly different for improved air flow/ efficiency. You could hand port them, but without bench flowing the head, I'm not sure if any noticeable gains could be achieved. The TB head along with its performance cam. High compression piston, race gas, and a few other mods I have on my ssr160, definitely makes this thing a rocket.
Yea I've never seen that before. I bought it with thr motor blown, and the kid told me it just locked up 1 day. After the rebuild, I practice lap the shit outta it, no issues at 5H. So I'm assuming it was probably ran low on oil, or the valves were tight, or from me watching how the previous owner rides, he probably blew it up by revving the crap out of it, or blipping the throttle aggressively and constantly while in gear/ under load.
@@QuantumMotorWorks I’m hoping the cause was one of the first two options you listed, cause on my pitbike I’m pretty hard on the engine and think it might be at risk for this. But mines gotta have over 100 hours on it and hopefully it’s one of them things where if it hasn’t broken yet it’s not going to. Also mines only a 125 wich might help
@@jacobrudolph4097 Tbparts seems to be a legit online site. I've gotten some special parts for my build from them. I believe they also have some universal diagrams.
It should match up, although you would need to check the valve to piston clearance once installed because the tolerances probably wont be the same due to different engine cases, piston, crank.
The Z155 is basically the same head. I have found that matching the ports to the gaskets makes a big difference and cleaning up the whole port with most of the work in the port floor is well worth doing. The cam sprocket has been slotted a little too and its let the engine rev a lot more with more power overall and a couple BHP gain at peak power. On the dyno the difference can be seen as just a better power curve with gains almost everywhere apart from really low RPM due to the slight change to the cam timing. But the motor is never down that low so its not really even worth worrying about.
I’m not sure about z155, but my ssr160 makes gnarly power for all of its mods. Most of the bolt-ons were from @TboltUSA
@@QuantumMotorWorks I spent time on my motor as in the UK pit bike racing is mostly supermoto style and on tarmac. So power is all important and with dyno time on carb set up we found about 0.7bhp which is a good gain when the dyno only reads 12.2 to start off with. Now we are up close to 15bhp on that same dyno. But we have done a few things because TB heads are not legal in one of the race classes, well the roller rocker head is not at least. So we have re-profiled cam followers now, mappable digital ignition, ported head, CNC machined inlet and a much longer under engine exhaust which runs up through the swing arm, next to the shock, and out where the normal MX style exhaust would exit. The MB Factory and Ayrton Pit Bike valve retainers are safe for at least another 1000 to 1500rpm as we did drop a valve with the stock retainers and being much lighter there is now no more awful valve float at high rpm too. The only real difference between the YX160 you have and the Z155 is the closer ratio gearbox and ignition system. The rest of the motor is basically the same in performance terms. The YX has a longer stroke but it seems to still rev out the same as the limit is valve float not simply running out of RPM due to the longer stroke.
If we could run the TB roller rocker heads then I know it might give us more power but the cost of that kit is just too much for a kit we cannot race with unless we run the Open class with 190 and 212cc daytona engines or Honda CRF150's with 185cc big bore kits and 85cc to 112cc two stokes . It would just be killed on track.
@@YAMR1M yea I just play on around on my bike and smoke all the dads and kids on the local tracks
@@QuantumMotorWorks I have to try to keep within rules here for racing. I am only having fun myself, but I am also the UK importer for the bike brand so if someone wants to test the bike I need to let them test a bike close to one they can race. I let a guy race it a few weeks ago and just arrived at the track. he had never ridden the bike before and it started to rain as soon as he went out on slicks and we had no rain tyres with us. He finished in 3rd place on a bike he had never seen before, ridden before and in the rain on slicks, Now he wants to test the bike in the dry as he was the only guy out there on slicks all day and never finished lower than 4th. The extra RPM and not so much torque at lower RPM let him use the throttle harder. It is fun to see and engine I built do so well against some very expensive bikes and engines.
@@YAMR1M I need to make some follow up videos on my mini bike builds. Maybe in the upcoming weeks. Let me know if you ever plan on coming out to california for some riding....I'm the process of building a rental fleet, and may have some mini race bikes available.
Ive literally had the exact same thing happened to me with the same motor, I only put 3 hours on it and 95% of that was tuning so not even reving out, I honestly do think the stock Crank was just junk, timing side skipped/sheared and it totally lost spark. Was a good little motor before that
ive def considered this kit for my 110 but from what the TB head casting looks like.. I think I'll hold off. also the ports may be a bit different but far from ported. I think I'll just be modifying my own head.
So far so good. I think I have 3 hours on my meter since the overhaul. The ports are indeed not cnc or hand ported, but are casted. They are larger in diameter compared to a stock 110 cylinder head, and the valve angle is slightly different for improved air flow/ efficiency. You could hand port them, but without bench flowing the head, I'm not sure if any noticeable gains could be achieved. The TB head along with its performance cam. High compression piston, race gas, and a few other mods I have on my ssr160, definitely makes this thing a rocket.
ruclips.net/video/sAAqppHe_dU/видео.htmlsi=-nrzL4FL2ryq_6YY
I need to make a follow up video/ or a track day video to really shows how it rides compared to a stock klx110 lol
Nice vid! What you said about the crankshaft shearing off really concerns me though I thought yx was a good brand
Yea I've never seen that before. I bought it with thr motor blown, and the kid told me it just locked up 1 day. After the rebuild, I practice lap the shit outta it, no issues at 5H. So I'm assuming it was probably ran low on oil, or the valves were tight, or from me watching how the previous owner rides, he probably blew it up by revving the crap out of it, or blipping the throttle aggressively and constantly while in gear/ under load.
@@QuantumMotorWorks I’m hoping the cause was one of the first two options you listed, cause on my pitbike I’m pretty hard on the engine and think it might be at risk for this. But mines gotta have over 100 hours on it and hopefully it’s one of them things where if it hasn’t broken yet it’s not going to. Also mines only a 125 wich might help
Where is the best place to get parts and parts diagrams for a yx160 in the US?
@@jacobrudolph4097 Tbparts seems to be a legit online site. I've gotten some special parts for my build from them. I believe they also have some universal diagrams.
Do you have an install video or after going over the performance gains?
No, not yet. I need to make 1......
if i install the head cylinder of yx160 to KLX 110 can be fit?
It should match up, although you would need to check the valve to piston clearance once installed because the tolerances probably wont be the same due to different engine cases, piston, crank.
@@QuantumMotorWorks thank you very much ♥️
sir does the cylinder head fit to klx 110?
Read the comment below
how about the stroke sir??just wana get more info to upgrade my kawasaki fury sir...