200x stroker...again

[mullet_boy]

I posted a while back about making a 200x stroker from parts of a crf 230. I've got a new idea now. A cb125 rod is shorter, and i found a web site about a guy who made his own stroker out of a 125. The 125 rod is around 8mm shorter than the stock 200x rod. If you relocated the rod pin in the crank using bushings 8mm up, and used the 125 rod, you would have an 8mm longer stroke. This make sence to anyone else?...heres a link to the 125 stroker motor http://www.kaila.net/tl125/tl125bigbore.html

[WIkid500]

I like it. I think it could be done with some parts. But for me the time it would take me to machine parts and find the right rod it's easier to just pay Powroll 200 dollars and have it done right. I don't want junk with a spacer plate and cam chains that are spliced together. I will be doing a 200x stroker motor this spring and everything will be done my me except the crank and the rod. I'm going to send them a crank with no bearings and a rod, they can do what needs to be done.

[ATC Rider]

I like it. I think it could be done with some parts. But for me the time it would take me to machine parts and find the right rod it's easier to just pay Powroll 200 dollars and have it done right. I don't want junk with a spacer plate and cam chains that are spliced together. I will be doing a 200x stroker motor this spring and everything will be done my me except the crank and the rod. I'm going to send them a crank with no bearings and a rod, they can do what needs to be done.

I think he means the 86 200X, powroll doesn't make any thing for 86-87 200X's

[SWIGIN]

I posted a while back about making a 200x stroker from parts of a crf 230. I've got a new idea now. A cb125 rod is shorter, and i found a web site about a guy who made his own stroker out of a 125. The 125 rod is around 8mm shorter than the stock 200x rod. If you relocated the rod pin in the crank using bushings 8mm up, and used the 125 rod, you would have an 8mm longer stroke. This make sence to anyone else?...heres a link to the 125 stroker motor http://www.kaila.net/tl125/tl125bigbore.html

your thinking right, thats how they do it but when another rod cant be found they shrink the the stock one down.

8mm is a good bit .....as a rule i like to think that 6mm is the end of whats reliable

i have seen 10 and 12mm strokers fly apart after no time at all but they werent built like powroll builds them

[mullet_boy]

I'd like to use a stroker kit from powroll. But unfortunatly i don't have the money, and after reading some reviews on here i don't think its for me. The guy i read who did his said it ended up being a stupid amount over what the price on the site said. (due to replacment parts or something they said he needed i think). the crf 230, the 200x and the cb 125 are all "basically" the same motor aside from stroke and bore. The cb is 8.3 mm shorter stroke then the 200x, the 200x is 8.4 shorter than the crf 230. The cb has a smaller bore, and the 200x and the crf are close (within a couple mm). If im thinking right, the only parts i should have to machine are the bushing peices that relocate the crank pin in the crank. The rest of the motor should be stock aside from the shorter cb125 rod. 8mm shorter rod, 8 mm offset crank pin, nothing should change as far as the rest of the motor correct?

atc rider-nah ive got an 84..I'm just too poor to spring for the stroker kit from powroll...

[200x Basket]

the powroll kit will be cheaper by the time you are done. the machine work alone will cost you more then their kit.

[hondahaulic]

so if the crank pin is 8mm higher, you would be gaining 16mm of stroke right? what would the final cc's be of the engine?

[300rman]

If you relocated the rod pin in the crank using bushings 8mm up, and used the 125 rod, you would have an 8mm longer stroke. l[/url]

hmm.....your math is off. 8mm movement on the crank pin would be 16mm total change in the stroke. it moves the piston 8mm farther UP on the upstroke, but it also pulls it 8mm farther down.

so, if you gain 8mm with the shorter rod, moving the crank pin will equal a 16mm greater stroke.

[Ed200x]

I'd like to use a stroker kit from powroll. But unfortunatly i don't have the money, and after reading some reviews on here i don't think its for me. The guy i read who did his said it ended up being a stupid amount over what the price on the site said. (due to replacment parts or something they said he needed i think). the crf 230, the 200x and the cb 125 are all "basically" the same motor aside from stroke and bore. The cb is 8.3 mm shorter stroke then the 200x, the 200x is 8.4 shorter than the crf 230. The cb has a smaller bore, and the 200x and the crf are close (within a couple mm). If im thinking right, the only parts i should have to machine are the bushing peices that relocate the crank pin in the crank. The rest of the motor should be stock aside from the shorter cb125 rod. 8mm shorter rod, 8 mm offset crank pin, nothing should change as far as the rest of the motor correct?

atc rider-nah ive got an 84..I'm just too poor to spring for the stroker kit from powroll...
Yeah I read his post about the charges. Essentially he was torqued because the company informed him that the main bearings were bad and something else too.
What I don't get is this. The guy was in the process of building up this motor of his so it would crank out beau-ceau power, right?! Well if it were me (and yeah it has been me . . .more than a few times) and I got this no-doubt high mileage lil' motor all torn apart so I can GET SOME SERIOUS PONIES outa it--- well I get serious about all the Critical major parts. Years ago I sent a crank to Powroll and I included brand new Main and rod bearings and a new cam sprocket and request ed them to change out the used stuff and charge me accordingly (Ended up costing less than the local honda robber- er - shop to do it). Because I wanted my new torqin' ass rippin' thumper to be 100% --period!
nuff-said.

[cr480r]

It just seems to me that adding 16mm of stroke and reducing rod length is a good recipe for trouble.. I would use a longer rod, a cylinder spacer, and a longer timing chain...if a shorter piston is not available.. a good rod/stroke ratio is important for durability and reliability