200x stroker motor Piece of History

[shortline10]

Picked up this old original 200x stroker motor from ex team Honda rider Tommy Gaian . Just came in the mail on Tuesday . Missing the head which he said was shot but came with a couple cylinders and pistons . The bottom end was still pretty much together . The stroker crank is really nice , looks to be lightened a-lot . This is the old school way to stroke a 200x by using a stock rod and moving it out 5mm and using a 5mm spacer plate to raise the cylinder . I did notice that 2nd gear was trashed and this is probably why the motor was apart as Tommy couldn't remember what was wrong with it . As you can see from the pics I tore it completely apart and will clean , inspect and replace the bad parts . Check out the pic of the stroker next to the stock crank . Also the flywheel weight was removed and looks to have been lightened a bit . I haven't measured the stroke of this yet but I believe with the 5 mil spacer gives you 5mm more at the top of the stroke and 5mil more at the bottom of the stroke for a total of 10mm stroker ? If anyone knows how this works please let me know ? I did check the rod and its @ stock length . I've only used the powroll stroker set up on the 200x which is totally different so any help is appreciated on this one .

[WIkid500]

Hey Shortline, that is an awesome old motor you found! I am in the process of building a stroker motor for my 85 200x. I would like to do the exact thing you have going on here but what did they do for the cylinder/head studs? Are they longer to make up for the spacer plate, or are they just long enough from factory that you don't have to mess with them? Thanks!

[oscarmayer]

sweet find! no sure how stable it is as from what I understand the spaers palces leaked quite a bit, but it may be worth a try.

[Bryan Raffa]

yes Im intrested also.. I got one waiting to be built..more info.. I know for shure Im going Stroker..

[shortline10]

Not sure about the cylinder studs length yet because the top end was off but will check it out tomorrow for you . I did check the timing chain and its definatly longer than a stock one .

[KASEY]

mhhhh,, why would you need a stroker to run in the 200cc class??? i knew alot of cheaters back in the day,,,,

[shortline10]

185 cylinder and a stroker made for a bad a@@ combination back in the day and still legal in the 200 class . Made lots of power that way .

[Daddio]

The spacer plate is one way to compensate for the stroker crank. There is a guy here in town who used to own a motorcycle shop back in the day and he said that he sent parts out to Powroll and Mickey Dunlap to have them worked over and when he got them back he inspected what they had done and copied some of their ideas for his customers. He told me that powroll shortened the rod to compensate for the stroker cranks. This guy is a goldmine of knowledge. It's hard to get him to open up but when he does it's nothing short of amazing, what he knows.

[WIkid500]

The spacer plate is one way to compensate for the stroker crank. There is a guy here in town who used to own a motorcycle shop back in the day and he said that he sent parts out to Powroll and Mickey Dunlap to have them worked over and when he got them back he inspected what they had done and copied some of their ideas for his customers. He told me that powroll shortened the rod to compensate for the stroker cranks. This guy is a goldmine of knowledge. It's hard to get him to open up but when he does it's nothing short of amazing, what he knows.

Daddio, Powrol still does this to 200x cranks. I'm just not a huge fan of the short rod. I don't like the extreme crank angles you get when you do this. I'd rather keep the rod long and have less side pressure on the piston as it's going around. Makes more power and lasts longer with the long rod.

[250r'en +TCB]

Awesome score you have their my friend!!!

[Daddio]

Daddio, Powrol still does this to 200x cranks. I'm just not a huge fan of the short rod. I don't like the extreme crank angles you get when you do this. I'd rather keep the rod long and have less side pressure on the piston as it's going around. Makes more power and lasts longer with the long rod.

I agree with what you're saying, I was just telling the story.

[Dirtcrasher]

I wouldn't worry about the spacer plate leaking. No gaskets (if you can get away without them ) and Hondabond/3Bond that puppy.

I'm sure it's a NASTY motor!! I'd love to take a spare motor and build an 87 200X stroker motor. No one uses the "shrunken rod tech." on the 86/87 crank though........I think I have to get the pin moved and build a spacer for it myself.......

You <85 guys have to careful with the kicker gear BS and address that when your building the motor

[WIkid500]

Dirtcrasher I'm going to have a friend cut a few spacer plates on the water jet this fall. If you can make a cad or solidworks drawing for the 86-87 I can get a few made. After they are cut I can throw them on the surface grinder at college and grind them to size. That way they will be flat, and we shouldn't need gaskets.

[bansheejoel]

here is the pic of my 411 stroker engine that mickey dunlap at four stroke tech. built for team kawasaki back in the day. Ported and polished, big valves with a big set of cams.....oh and ofcource the stroker crank and spacer. Havent had any probelms with the spacer plate.....oh and this thing is MEAN since stock it was a 250 lol

[greenhuman]

On your image of the stroker and standard crank, measure from the top of the main bearing to the top of the pin on the standard crank and do the same on the stroker and see what the difference is then double the difference and that will tell you how much it is stroked.
I have never had any issues with the short rod 200X strokers as they are not stroked all that much, only 3mm at the pin. That does not increase the angle enough to create a problem. The long rods are OK as well but having to run old stretched cam chains for one thing negates any advantage over the short rod cranks.
Sparks used to build the Team Honda four strokes I believe and I think you will find that crank is a 64mm. The spacer may be thicker because it may have run a piston out of something else to keep it in the class.