Back me up on this

lorraine

Well-Known Member
Messages
283
Location
new york
I was cleaning up the smoked motors around the shop and zipp'in off the parts that could be used on longblocks. keeping rovan,kingmotor, OBR , plain Zens parts sorted by make, I found the the clone motor flywheels had alot weaker magnets when sticking the coil to them to keep them as a set. I took a zen flywheel and stuck the coil arms on and snap it back off for a feel and did the same for the rovan and kingmotor, The zen flywheel has a very strong mag pull off and the others about 1/2 that. Would it make sense that the stronger field flywheels would overall work better ? I think it would help better at startup when moving slower to give a good snap at plug when pulling. Boy I can't believe how many OBRs these guys have cooked in the last year, Glad I did not pay for this pile of now scrap, ouch!!!. I'm glad I run RCMKs and R/C max , They both have been very very good to me and my wallet. I do know a bunch of these motors are cooked down from Amsoil cause I can smell the stuff in them.
 

John Parks

Well-Known Member
Messages
443
I run nothing but amsoil and never had any issues. Likely there running 40 or 50:1 which is a no no. Amsoil, and castor 927 are my top pics.

As far as the magnet issue goes it wouldn't surprise me a bit. Zen, obr, etc are much more quality.
 

lorraine

Well-Known Member
Messages
283
Location
new york
Ya the crew that burns everything up shows up to run with that nasty kwik fill super kwik that smells like paint thinner, and most of the so called motorheads have their ratio rite cups sharpie marked REALLY low to bottom of it . They laugh at me cause I mix at 18:1 but I have dyno time to prove that oil makes power. The builder of our motors has some of the fastest PUM motors in the world and their team run 16:1 . My Honda CR500R picked up 7 full horse when switched from 32:1 to 20:1 and a quick rejet. In my r/c motors I run Sunoco Surge race gas and 927 in all of mine RCMKs and the 3 R/C MAX GT40s. My Daughter runs yamalube cause the the premix oil she runs in her YZ250 and uses it in her 5B with great results also. Oil makes power!
 

Polar_Bus

Well-Known Member
Messages
237
Location
New Hampshire USA
Don't blame the "oil" for a "cooked" motor. Amsoil Dominator is a WELL respected oil in the snowmobile circle. Cooked motors are either pushed too lean in attempts for max rpm's (which tuning novices think is max hp, when it's not), air leaks which festers lean conditions or lack of air filter maintenance. It's extremely crucial to maintain a clean, well oiled and air tight air filter seal or you WILL blow up an engine in short time. I've blown three 2 stroke engines in the past 31 years, two of which were all me, the third was a ghost failure I never did figure out. I too am learning that these CY engines are nothing but super CHEAP mass produced engines. In China it's ALL about making a $100 product for $.10. They cut corners in EVERY aspect of manufacturing from metallurgy (elevated levels of junk carbon content instead of quality nickle), to skipped machining operations , poor tolerancing, and absolutely ZERO product QC prior to export shipment.
 

Z.hb71

Well-Known Member
Messages
5,784
Don't blame the "oil" for a "cooked" motor. Amsoil Dominator is a WELL respected oil in the snowmobile circle. Cooked motors are either pushed too lean in attempts for max rpm's (which tuning novices think is max hp, when it's not), air leaks which festers lean conditions or lack of air filter maintenance. It's extremely crucial to maintain a clean, well oiled and air tight air filter seal or you WILL blow up an engine in short time. I've blown three 2 stroke engines in the past 31 years, two of which were all me, the third was a ghost failure I never did figure out. I too am learning that these CY engines are nothing but super CHEAP mass produced engines. In China it's ALL about making a $100 product for $.10. They cut corners in EVERY aspect of manufacturing from metallurgy (elevated levels of junk carbon content instead of quality nickle), to skipped machining operations , poor tolerancing, and absolutely ZERO product QC prior to export shipment.
Exactly. I've never ever heard of Dom killing a motor, now I don't have as much experience as u, but still. Also, cy IS mass produced crap. Hope you can make yours reliable by tearing it down, checking/fixing clearences, ect.
 

lorraine

Well-Known Member
Messages
283
Location
new york
You don't have to tell me about QC and metals as our family has owned and operated a Hi production screw machine shop for 72 years. We have seen it all in industry . Was not trying to stomp Amsoil as I was only going by the pile of dead souls on shop floor and what my nose told me was on their last dying breath. A motor is only as good as the wrench head twisting the tools and mixing the fuels.
 
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lorraine

Well-Known Member
Messages
283
Location
new york
Just to square things up I do Know for fact that oils for liquid cooled 2 cycle engines is different than free air/fan cooled oils, The operating temps between the types of engines is quite a large swing. Most new oils will get along with both but some oils are targeted more to one type of temp operating range. I always look very deep into lube packages on oils so I know what i'm getting into. We have testers here at shop to test for shear , PH ,visco , surface tension , suspension micron on the truck loads of oil that comes into our shop , I test each and every one of the 55gal drums before they are used in our machines. I have been playing with the slippery stuff for many years
 

Polar_Bus

Well-Known Member
Messages
237
Location
New Hampshire USA
Lot of old skool racers swear by castor based oils for high rpm air cooled race applications. I gained a lot of knowledge reading up on "What oil is best" posts on the Yamaha KT100 kart racing forums. Those guys know their stuff ! I have a gallon of Klotz Benol that i tried way back. Problem is that castor based oils get very thick in cold temps. Not a good situation where i live up in the cold northeast.
 
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lorraine

Well-Known Member
Messages
283
Location
new york
I like the maxi 927 the best, I only mix up a gal at a time and track is right out back shop door to pond track, I'm 50miles from buffalo, NY and hear ya on the cold. The dyno we use is at a F1 kart shop and endorsed by Yamaha and Rotex so I know the numbers we get are real and not BS. He is in all the time for me to machine kart parts and I trade him for free dyno time in his shop. Perfect for me as His setup cost over $30.000 for the dyno. I have seen some pretty sick kart motors over there. Those liquid cooled Rotex are no joke!!!
 

Seandonato73

Well-Known Member
Messages
2,065
I run klotz super techniplate. Its synthetic and has the caster oil in it. Figured my old man ran unlimited offshore boat races and used it. It's good enough for my stuff. And normally you would run a TWC rated oil in a boat or liquid cooled engine. Air cooled is a JASO spec I believe. Some oils can cross over to both, but a TWC oil should never be used in an air cooled engine. It cant take the higher temps
Nice touch have access to a decent dyno that engines this small can go on👍
 

lorraine

Well-Known Member
Messages
283
Location
new york
I welded and machined up a motor plate/cradle that goes into a tapered receiver to meet his dyno lock head the crank centers and his input shaft meet head on perfect every time with little to no setup time. the dyno is made for the kart industry and Rotex has them in their engine plant, Top notch equipment. I found in Summit Racing a O2 sensor that will play well with 2 cycle exhaust mix and his firmware on dyno will read it. MSD says about 4 inches down stream from piston wall face to weld in bung in header straight to mount sensor, I'm going for it!. Also going to machine up a hookup horn so I can plug in his CFM flow box to get flow curve data vs O2 level in exhaust stream. last going to machine a magnetic pickup block to mount near flywheel to read true RPM and the dyno can plug and play with this also for data. I'm lucky we both need each others shops or this would have never happened..........
 
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