in the manual you can see an engine with an os-shaft and only for this version you need the added nut. your engine has a sg-shaft and so you wolud need only a normal nut. ... but, cause of the stocker flyweel is very thick, there isn´t enough thread left, to fix the flywheel safe on the shaft.
the next point is, using the stocker flywheel you will only have a two-shoe clutch, which is permanently overheating and burning down your shoes.
also the diameter of the stocker flywheel shows no sense to me, only if you would cut the the pan to use an old handstarter. and then, when the flywheel is free to the ground, the engine will shut down in case of groundcontact. (ok, not on snow, but on ice and other surface) next negative thing would be a hole in the pan to get snow, water and dirt in the sled...
so you don´t have to cut the shaft, just take a normal 3 or 4-shoe clutch system from a buggy or a nitro monster and you will be happy.
i´m using a complete 3-shoe clutch from a savage with mugen shoes and it´s working fine.
i added a pic where you can see the savage flywheel and my servo safer from a lightning
< Message edited by mac.fee -- 2/10/2007 10:48:57 AM >
i was using the engine from a savage with rotostart for several times, but cause i don´t want to carry the rotostart ( and taking care of full batteries for it ) with me, i went back to my hyper21 pullstart.
my sled is running faster with my hyper, because the hypers rpm are much more.
i´m allways pre -heating my engine in the cold, by using two handwarmers (working with zippo fuel safety about over 7 hours) witch i put near the engine before i´m leaveing from home. with this method, i haven´t any stress in starting my engine, it will start mostly with the first pull.
next thing, .21 engines vs. bigblocks:
because we haven´t any possibility to change the gearing, there is no sense for me to put a bigblock in my artattack, only if it would have lots of more rpm´s. i think nearly evrery .21 engine has enough torque for the artattack, because the most problem is to bring the power to the ground, not only to have it.
a further point against bigblocks is the running time. for example with my hyper21 i have running times up to 15 minutes, with the .25 force engine they are under 10.
Posts: 200
Joined: 12/1/2005 From: Riverhead,
NY, USA Status: offline
Well,
My Art Attack Snowmobile is finally complete. Muffler for my .26 engine arrived.
I fired it up last night and had it run a few feet. Looks like everything is in working order.
I considered going with a brushless electric set-up but nitro is so much cheaper these days that I just went with it. (I'll save brushless for my 400 size helicopters---it works great in them and most of them come with a pre-packaged brushless system to keep it easy).
Now if I could just get some good snow here in NY, I could get this thing out for a real test run. I'll post when I do.
By the way, can you guys tell if I have the newer fuel-proof model from my pics above (about 3 or 4 posts up).
If you don't have the fuel proof one, how much nitro can you get on it before it's a problem?
Posts: 200
Joined: 12/1/2005 From: Riverhead,
NY, USA Status: offline
Thanks for the advice on the clutch and engine, mac.fee.
I did end up cutting the shaft after the threads on my engine and then I was able to fit the stock clutch and I tried the snowmobile last night and it seems to work with this setup.
I will keep in mind your words of advice and consider other clutch/flywheel options if I encounter trouble with this setup.
I don't think I'll get to use the sled too much, though as we haven't had much snow where I live this winter
Posts: 431
Joined: 11/7/2004 From: Ancaster,
ON, CANADA Status: offline
Hey guys i got my sled up and running this evening man did it rip it wouldnt do much on the ice but when you got it on that powdery snow it certainly did well. The only problem i had was with the exhaust, im guessing the spring that holds it does not have enough tension to have a tightseal between the header and the that little black seal so while i was running it the exhaust gases and the extra fuel comming out of the engine were going inside the the shell of the sled and it ended up melting my soft gas tank(my tank was positioned underneath the pipe) Any suggestions on how to get a tighter seal for the header?The track also kept comming off of the back idler wheels is there anyway to fix this? And im also thinking about studding the track not sure what to use mabe a #6 tapping screw? I will do two screws every other bar on each side of the track. Let me know what you think.
Posts: 200
Joined: 12/1/2005 From: Riverhead,
NY, USA Status: offline
I'm with you on studding the track, Alex. I recently got mine up and running (after having it in a box for about a year) and I'm really impressed with this model.
It really doesn't move on the ice and the engine just revs like crazy, spinning the track. Studding it (which I did once with an old RC car for snow use, I think it was an RC 10 and I ran wood screws from the inside of the wheel to the outside and it really bit in just about any conditions).
Anyway, I haven't done it yet but since everything is icey around me, I think it has to be done. Let us know if you have success and how you go about it.
Posts: 431
Joined: 11/7/2004 From: Ancaster,
ON, CANADA Status: offline
Ok i studded my track no really big proformance but my sled was runnin bad like i said before my gas tank melted, due to the pipe heat so i mounted a larger tank on the tunnel, after about a min or two of it running sluggish i looked inside the shell and it was full of gas so i figured there was to much gas going to the engine with the gravity feed on such a large gas tank(16 oz) so i couldnt really test it but i noticed the track was alot tighter and i really had to rev it to get it spinning. ill let you know more when i get a better tank.
Posts: 200
Joined: 12/1/2005 From: Riverhead,
NY, USA Status: offline
So you think I should forget about studding the track and just wait for the right conditions to run it? It definitely ran well when snow had just fallen and there was a thin covering. The thing just picked up speed until it was flying, definitely over 20 mph on the grass with light snow.
Also, did you use the stock tank. I actually find that it works pretty well. I mounted mine under the seat (I think you can see it in the pic above) and haven't had a problem with it yet.
I'm used to using a pump to put gas in my models because I mostly work with heli's so I just used my heli pump to put the nitro in and it was no problem although after reading from a few sources, alot of people seem to not like the stock fuel tank.
Posts: 431
Joined: 11/7/2004 From: Ancaster,
ON, CANADA Status: offline
I would forget about studding it for the moment until i can test it out more the tank was working fine until it melted but when the tank is on the tunnel i find to much gas goes into the engine and it leaks out my roto start. It also needs a new gasket but still that much gas should not be comming out. With the studs at half throttle its not doing much also i just noticed that they hit the top of the tunnel which will cause it to slow down and show poor accleration ext.
Posts: 200
Joined: 12/1/2005 From: Riverhead,
NY, USA Status: offline
Keep me updated on the studding of the track situation, but for now I don't even have ice here to run it on because everything melted in the past few days.
Luckily I got it out a few times when we had a little accumulation here but I was pretty satisfied that it ran pretty well after a fun build.
I'll try it again when I get the right conditions.
I think people talk about running it on grass but I ran it on the grass with the lite snow and a lot of grass got caught in the track so I'm not sure it that's a good way to go?
Posts: 566
Joined: 6/16/2006 From: mcyville,
WI, USA Status: offline
i've been real sleding all my lifr and i would definatly addvise studding it. the picture thay showed doesn't have enough studs. when i studded tires for my rc trucks i used 150 studs per tire. reak skeds run anywere from 96-196 on average so the like 10 in the picture is not enough
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SHAKE AND BAKE!!!!!!!!!!!!!!! braaaap...braaaaaaaaaaaap........braap... brap..brap....BRAAAAAAAAAP!!!! snowmobiling is
Posts: 431
Joined: 11/7/2004 From: Ancaster,
ON, CANADA Status: offline
Ive also been running real sleds since i can remember and put two studs every three bars so thats 60+ studs on my art attack, it just causes to much extra weight i think now it has slo
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RE: Art Attack Nitro/Electric Snowmobile Thread - 
