ive been talking about this project and i just thought i would give an up-date!!!!![img]i/expressions/face-icon-small-shocked.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img] Well after a rediculous drive to San Diego and a big wad of cash, i am a bit PISSED!!!! after stroking a motor out with lighter internal parts you would think it would get a higher dyno# than a normal 720, BUTT, it came out to be only 61HP with 52 ft.lb torque.......If you can believe this, i started to go over motor to make sure everything was up to par and to my amazement i found out,[1]. it had 2 different kinds of plugs in it ..[2]. one spark plug was quit a bit longer than the other and [ive never seen a plug like this one]...[3]. the inner spark plug was not screwed in all of the way,[4].. it looked like a 3 year old put carb and boot back on it [ barely attached ]...[5] within 3 minutes of running motor the temp rised to about 180 degrees and was climbing so i shut her down...W.T.F it is 13:1 compression, the only thing i can think of is that it is detonating because i think i have 100 octane in it {which was in it for dyno}, of course it calls for higher, i know that the new parts can be causing friction, and need to loosen up and break in..everything in motor is new, could this cause it too run hot also besides detonation??Well to make a long story longer all i have to say is, that when i put 114 octane in it tomorrow, if it runs hotter than my GREAT running 720 @ 14.1 compression which doesnt break 165 degrees after pounding it, SOMEONE WILL PAY THE PIPER IM NO mechanic, but when i am done fixing someone elses mistakes myself i will put up some real dyno#s

 

dude that sucks about the workmanship, there's no excuse for that. hope it works out for you like you want, and like it should.

I'm curious about you temperatures you mentioned, because a stock DS will break 200 degrees frequently when ran hard, which is quite alright. The thermostat doesn't even open to circulate coolant until past 180 degrees. your 14:1 compression ran at 165? WTF? I gotta wonder about the integrity of the gauge.

 

high tower did you get a PM, the gauge is fine, but on 14:1 bike i have not ran lean YET on methonal it doesnt even break 155

 

i only hill shoot and run fan with toggle switch constantly, i will make about 5-7 passes and let cool off for about 5 minutes with fan running, then fire back up and it drops to 150 again, every now and then it might jump up to 170 but rarely.. thats only when i get carried away.

 

its always been the standard that fuel vaporizes and burns best at 180, hence most vehicles having a thermostat to maintain somewhere around there, and I know from my gauge that my bike will not run peak without being warmed to operating temp at least 180, in the winter I won't even put it in gear until I get past 170 on the gauge, and I maintain 190-200 all year, winter snow and summer heat.
But, I don't have the compression and setup that you have either, I'm sure that makes a differnece, thanks for sharing.

Does your new 763 have an aluminum cylinder, or is it sleeved, and did the old 720 have a sleeve or was it aluminum? A steel sleeved motor will show lower coolant temps because the heat dissipates through it much slower, with combustion temps higher, and the aluminum/nicasil cylinders will have cooler combustion temps as a result of faster dissipation to the coolant and coolant temps will be higher. IF, and I say IF 'cause I don't know what setup you had, but if the 720 was sleeved and the 763 is aluminum, that would explain the 763 showing a higher coolant temp, but combustion temps are actually lower as a result of the coolant wicking the heat faster through the aluminum wall.

 

well that really stinks, i kind of know the feeling right now i have my sons honda at the dealer being worked on oh i'd say it's been there a month, anyways i need to figure out what is wrong with them. i guess gary spoiled me with the quick turn around. what is the torque difference on the two machines? i could see the horsepower being somewhat similar but the torque should be very different. well hope this all works out for you, and thanks for the honest report. i'll let you know the dyno report on mine as soon as powroll gets done working on those little xr 50 machines, there set up for something and are waiting to change over. but they said they are needing to get on that 450 yamaha soon so it should only be a week or two. oh i think when i fired mine off i had about 98 octane and i remember it got warm just running, but after putting in the 110 it seems to run cool i only hear the fan after several hard runs same as the other ds's i run with.

 

Hightower i think the sleeves are made out of cast iron or steel, both sleeves are the same, the bigger bike is just stroked, You may be right about the fuel burning at a higher temp, but the 720 puts out great power at 165degrees, but i have had motors that DO run better at higher temps and it did run better as it got hotter sometimes i noticed, do you think the different length plugs had something to do with power loss and detonation?? Sandman, Samcoe Performance told me that i had 15% more torque than the 720s but i dont really believe it until i get the right fuel and jetting and dyno it myself, YOURS got hot too?? that makes me feel a bit better i will try higher octane today and give update, i can only see detonation causing the very quik increase in temp..

 

man i'd get the right range plugs in there, and some 110 and see where things are coming in at. when i said warm i just meant the fan would kick on, and it seems to kick on less with the higher octane, but along with what hightower said i think the temp on a ds runs a little higher than the numbers you are getting. that plug thing would concern me most mechanics are rather **** about things like that.

 

Hey **** Ticket! All quads run a little different. The 763 will give you more torque which it did, not necessarily more H.P. You also need to run at least a 105 octane and that will help temps. Also the motor needs a little time to break in, since the whole thing has been rebuilt. Also put in a cooler heat range plug in it. Put some DR9EA'S in there and that will help temps also. And #1 thing you just don't let your quad sit and idle for three minutes and not expect to see the temps climb, they aren't meant to sit and idle with or without the fan on. My best advice to you is: GO RIDE IT SUCKA!!!!!!!!![img]i/expressions/face-icon-small-happy.gif[/img] And have fun! You will see that after it breaks in it will be AWESOME!![img]i/expressions/face-icon-small-smile.gif[/img] Have fun and let me know how it turns out. I will probably be coming out there this week and I will tell you how good it runs ok? Laterzz

 

My motor is a stroker (733) and it depends on what kind of riding im doing. If im doing any slow trailriding the motor will get as high as 205. If im at the dunes racing or just flying around it doesnt get over 180. Just thought you would like to know.