KTM380/400ex hybrid

[brewster426]

i got a 380 2 stroke motor off a buddy of mine on a pretty good deal and i talked to a local mechanic and he said that it would vibrate so bad that it would break the frame in just a few mins..i work at a fab shob and some good fabbing wouldnt be a problem. i was just wondering if anyone had ever had any problems like this. thanks for the input

[jcs003]

look at the cr500 hybrid. do it how he did his.

[jcs003]

any progress. im thinking about this for a winter project.

[brewster426]

naw man..i have to heli coil the head bolts, but hopefully i can get time in between kart racing and work. im not in a hurry

[flyjum]

It will be fine.

If you can use rubber mounts that can help.

Also use flexbars that will help alot too.

Mine vibrates a bit but its not that bad not using a steering stabalizer is worse imo.

[bigbad400]

it wont vibrate too bad if you use all the mounting points on the motor and u hang your exhaust on rubber bushings or something, its the exhaust vibration that makes the most damage, rev a 2 stroke to 10000 rpm and see how she vibrates, it will shake u to pieces, hens why they use springs and rubber to hang 2 stroke pipes from the factory. i would put some sort of a hard plastic bushing on all the motor mounts too, or a big rubber spacer to keep it minimal, i worked on a cr500r/400ex hybrid, rattles ur cage let me tell ya, but we got it so its not bad, no worse than a blaster or 250r vibrates. (wich is bad ive had both, 250r is way worse)

[SRH]

we got a cr 250 hybrid...vibrates no worse than the old tecate 4's or quad racers

[jcs003]

updates???

[2muchquad]

we got a cr 250 hybrid...vibrates no worse than the old tecate 4's or quad racers

i agree i had a cr250 blaster and it vibrated no more than anything else,only in neutral when you revved it up could you feel the vibes,while riding its a non issue:)

[mx Eli]

look at this

http://www.youtube.com/watch?v=dS_jT8TdHGE

here is the forum this guy came from
http://www.ozatv.com/forum/viewtopi...r=asc&start=100

[brewster426]

got the 400 tore down..gonna try to have the 380 motor in the bike by wendsday. im gonna try really hard to make it to lorettas on the 15th of next month. i just need a 250r exhaust and a radiator. im selling all the 400 motor stuff too. check it out on the classifieds. ill try to get some pics up soon.

[tomtom79]

Sounds interresting lots of pics please.

[brewster426]

i should have some pics today...its coming along pretty well. i ordered a 250r exhaust. im going to have to cut it up and use some of the dirt bike exhaust that i have. and i have a yfz radiator on the way. i hope it doesnt shake my teeth out. its gonna be crazy fast.

[brewster426]

a few pics..you can see where i had to offset the motor a little to the left and foward. all i have left after today is making the head stay and welding one mount to the frame and cutting a old one off. and i have to cut the return spring bracket for the rear brake lever off for kickstarter clearance. its coming along nice. i got a yfz radiator today and my 250r exhaust should be here tomorrow some time .

[brewster426]

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[brewster426]

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[brewster426]

i got my radiator mounted today..it came out of a yfz450..it looks pretty small. im not running a fan. just wanting to get some opinions on if it is too small or not

[jcs003]

any updates? this is possibly my next build. you beat me to it dammit.lol

[chronicsmoke]

BUMP!

any progress on this? I've been thinking about doing this recently..

[brewster426]

I sold the motor to my cousin because I just didn't have the time or the experience to do it how I wanted to. We are putting it in a 04 yfz frame. It's almost done now. We have about 2 more hours of putting it back together to get it ready. If everything goes right it will be at the next TT national in sikeston Missouri. Probably in the pro am unlimited class.

[chronicsmoke]

Originally posted by brewster426
I sold the motor to my cousin because I just didn't have the time or the experience to do it how I wanted to. We are putting it in a 04 yfz frame. It's almost done now. We have about 2 more hours of putting it back together to get it ready. If everything goes right it will be at the next TT national in sikeston Missouri. Probably in the pro am unlimited class.

Make sure you post some pics up after it's done!

Was it alot easier to put in a yfz frame?

[brewster426]

Not really. He made his own motor mounts. And had to cut on the swingarm to get it to fit but it fits very nice now. We just got done with the exhaust. That was the part that sucked the worse. We only have 10 days to have a completely race ready bike. That national is June 10th and 11th. But as soon as we get it all together I will post some pics.

[brewster426]

Went to start the bike up and found out I messed the head gasket up putting the motor back together. Once we get that fixed we should be good be good to go. We have 4 days to get it ready for this national

[brewster426]

Gotta split the cases. Needs crank bearings. Might as well take our time and do it all right..ill post some pics soon.

[brewster426]

Anyone know where I can find a crank that's under a 1000 dollars. I'm gonna try to get this one fixed, but I would like a new one. It has pits on the crank where the seal goes. Any help would be appreciated. Thanks

[flyin cobbler]

PM sent

[brewster426]

Finally got this thing most of the way together. We were able to put it on the ground and crank it last night. I will try to post some pictures soon. I can't do it from my phone. It will be at Ashtabula for the TT national.

[chronicsmoke]

I was pretty excited when I saw someone posted in this thread, can't wait to see the pics/vids :)

[brewster426]

Hopefully it has the power we expect. I'll know this weekend.

[brewster426]

Way overdue, blew it up at the Ashtabula TT National. Heli coil gave up where I had all the head bolt holes done. Seized it up. Getting it fixed soon. It was fast with a blown head gasket. It's going to be nasty when we get done with it.