2nd gen 250r engine vibrations

[Tfields87]

Ok so after searching local ads for several months I can acrossed an ad for an 83 250r for $1700 or possible trade im really looking for a 3rd gen but there like hens teeth in this area so after about a week of texting back and forth we came up with a possible trade so I drive the hour to the meeting place we agreed with and out of the truck pops 2 kids 13 and 16 so if any of you can remember what it was like at that age you can remember the destruction we caused to our machines at least I do so they were happy with what I brought to trade but I was discouraged with the 250r the bike started first kick and idled great how ever I felt like the compression was a little low I've never owned a two stroke atc but have owned quite a few cr250s from early 90s to 2000s so after the had warmed up for a couple minutes I took it for a lap around the parking lot and couldn't get the bike to pull real hard It was almost like once it got to rpm where you would think the power band would come on it lost power and the engine vibrated like the lower end was about to come apart so I asked the kid why does it feel like that and his reply was it doesn't pull hard until 3rd gear so after a couple minutes of talking I decided not to do the deal and maybe do a little more research on my concerns so any help with this would be greatly appreciated since I'm new to the atc world my biggest fear is getting it home doing a top end and the fresh compression being to much for the lower end bearings to handle them being stuck with something I cant find parts for I've done a quick Ebay search for crank and bearings and haven't found any new cranks just used ones only 3rd gen liquid cooled new bottom ends. I also noticed the factory crank is almost egg shaped is this what's causing the vibrations I'm feeling any input would help also I'm looking at about a $900 dollar investment on this thing and it needs new wheel and axle bearings ,brakes, tires, and plastic to get in rideable condition that plus engine work has me questioning is it worth it thanks

[Tfields87]

Sorry for the long right up I really felt bad for the kid and I'm try to justify the trade

[ironchop]

What did you bring to trade him?

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[Tfields87]

85 250sx in good shape new brakes new tires no mechanical issues a good rider I ride almost daily

[ironchop]

Yeah from your description of both machines, you definitely should've walked away. I agree with your choice.

I've purchased trikes before that looked and ran fair but needed a topend and it ended up being an absolute money pit once I tore it down.

250SX get pretty good money around here, about as much as a similar shape 1st Gen R goes for

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[Rob Canadian]

Too be honest. I would walk away.

If it needed a bunch of stuff that was not looked after. I am sure that engine is not in good shape.

[Red Rider]

Engine counter-balancer out of time with crank possibly?

[Tfields87]

Guys thanks for the confirmation on the trade I felt the same way about the neglect

Red rider I'm familiar with counter balancers on harleys but how would it get out of time on the 250r? Do they striper would it be installed out of time

[yaegerb]

Guys thanks for the confirmation on the trade I felt the same way about the neglect

Red rider I'm familiar with counter balancers on harleys but how would it get out of time on the 250r? Do they striper would it be installed out of time

The gear on the counter balancer and the primary drive gear have dimples that have to line up when you install.

[Tfields87]

I'm going to rule that out because if this thing had ever been rebuilt it was a long time ago and somebody would have fixed it by now. Does anyone have info on new cranks anyone reproducing them?

[fabiodriven]

You can't just assume it needs a crank shaft based on what you know. You definitely did the right thing by walking away but there's absolutely no way of knowing what it's going to need without a bit of disassembly.

[Tfields87]

It's been posted for almost 2 months and hes still riding it I think I'll check back in with him here in a couple of months when I get back to work (I don't work winters it's my off season) and I get some cash flow maybe by then he will have blown it up and I can get it cheap enough to make it worth the restoration thanks for all the comments I'm still new here and I'm loving it every body has been very helpful