Stop sign cylinder

Gmbond · Post by **Gmbond** » January 13th, 2011, 12:37 pm

I'm pulling apart my 1994 motor here and I discovered the cylinder has the streaks at each stud. Fairly minor blowby marks tracking down the cylinder. It also has a fairly recent looking wiesco .50mm piston that hasn't been drilled.

I've never heard this motor run or performed a compression test/leakdown test.

What im after for info is should I just put it back together for now and do nothing as it looks clean etc....
Should I bore to the next size and new oem or vertex.

Hone it?
Drill the wiesco and run er Til I wanna rebuild it with oem or vertex??

Post by **AlisoBob** » January 13th, 2011, 1:04 pm

seanmx57 · Post by **seanmx57** » January 13th, 2011, 1:28 pm

Gmbond wrote: I've never heard this motor run or performed a compression test/leakdown test.

So you basically know nothing about the motor then...........

In the future you may want to consider checking the compression before the tear down. Leak test it too. Unless of course you are hell bent on a FULL rebuild.

Have you measured piston to cylinder clearance?

Gmbond · Post by **Gmbond** » January 14th, 2011, 1:34 pm

Hope that works first time I've posted pictures

So yea basically other than what I can see I don't know the history of this motor. Someone has done some polish work in the exhaust port but doesn't appear to have really had much material removed so I'm thinking it's pretty superficial work there.

I would have done a leakdown test but the head was already removed and compression test is hard to do when it's not in a bike. I figured for the cost of a base gasket it was worthwhile doing a visual inspection at least.

Gmbond · Post by **Gmbond** » January 14th, 2011, 1:36 pm

Never realized how hard it is to take a picture of the inside of a cylinder especially using my phone camera.

dubious01 · Post by **dubious01** » January 14th, 2011, 5:19 pm

have you checked piston to cylinder clearance? ring gap, and was it over heated?

Looks like the rings are deflecting / chattering off the top of the exhaust port, I would check chamfer, ring gap and piston clearance.

I would make sure it had coolant, and ensure it was circulating.
I am no pro but I would thing the stud area get the hotest when it overheats, and the gap would tighten up in those locations the most.

That piston is new. I am confident the stop signs were made with a different piston, and that motor had a fresh piston slapped into it without a fresh bore, or even honing it.

Gmbond · Post by **Gmbond** » January 14th, 2011, 5:54 pm

damn dubious i think you are onto something,

id completely forgotten this motor had nearly no coolant and was dribbling out of the weep hole on the waterpump before it was pulled,

the lack of matching stud streaks on the piston had stood out too.

iggys-amsoil · Post by **iggys-amsoil** » January 14th, 2011, 10:10 pm

It's all apart. Do it up right.

What piston is that? Never seen one with groves bt the rings like that.

kball1313 · Post by **kball1313** » January 15th, 2011, 11:58 am

Lots of wisecos have grooves in between the ring grooves.

Gmbond · Post by **Gmbond** » January 15th, 2011, 12:48 pm

It is a wiesco 636 554

I was just checking it out and the pins that locate the rings are loose... Is this a normal wiesco thing? Never seen it before.

100hp honda · Post by **100hp honda** » January 15th, 2011, 1:00 pm

has cutouts into the exh face. must be pretty old. been atleast 3 design changes since then that i know of.

dubious01 · Post by **dubious01** » January 15th, 2011, 4:14 pm

Gmbond wrote:It is a wiesco 636 554

I was just checking it out and the pins that locate the rings are loose... Is this a normal wiesco thing? Never seen it before.

Thats typical of older wiseco's, thye have done a llot of damage
Don't run it

2strokeforever · Post by **2strokeforever** » January 15th, 2011, 4:46 pm

its winter, you got no reason not to do it right

Post by **AlisoBob** » January 15th, 2011, 10:38 pm

I'd send the whole thing to Roosty for a Vertex makeover...

2strokeforever · Post by **2strokeforever** » January 15th, 2011, 11:45 pm

dont do it, give him time to finish mine first

Gmbond · Post by **Gmbond** » February 4th, 2011, 1:34 pm

Roosty gave me a good price on the "vertex makeover" however I've decided to go with my local race machine shop as they've treated me good before and I'm sure they appreciate the business.

I'll try to remember to take a couple of pictures of the job they do and post it up.

On another note I truly dodged a bullet with that wiseco piston. I was looking at it and one of the ring locator pins fell right out!!!

Post by **AlisoBob** » February 4th, 2011, 2:11 pm

Who are they?

Gmbond · Post by **Gmbond** » February 4th, 2011, 2:24 pm

Bondi Engines

http://www.bondiengines.com/

(despite the similarities between their name and my screen name there is no relation)

scooter5002 · Post by **scooter5002** » February 4th, 2011, 4:15 pm

Bondi has a huge name in MX and sleds in our area and I've never heard anything negative about them. Probably not a bad choice. If you aren't going to use Roosty, at least that's the right direction to go in. Had the good fortune to ride one of their full on race CR250 motors, a couple of years back, owned by a local dealer/ ex Canadian top 10 pro. That thing was a rocketship! Made my stocker look like a 125. Seems to me it was an 05 bike. Didn't change the powerband any, so it was dead on the bottom and all mid-range, but WHAT a mid-range. Definitely knows how to tweak a motor.

2strokeforever · Post by **2strokeforever** » February 4th, 2011, 4:28 pm

make sure they know about torque plate and know how to relieve the bridge

Gmbond · Post by **Gmbond** » March 4th, 2011, 12:11 pm

Just remembered to post pictures

Looks good, took a little while but they had a shop full of blown up sleds and I told them it was no hurry.

oggo69 · Post by **oggo69** » March 4th, 2011, 12:47 pm

sweet as job done there

100hp honda · Post by **100hp honda** » March 4th, 2011, 1:00 pm

for the hell of it you should double check their work. checked a stock oem jug couple days ago and its .0004" oval from the X and Y axis. plenty good enough for me. checked the wiseco piston that goes with it and theres .0035 clearance. job well done by honda and wiseco

Gmbond · Post by **Gmbond** » March 5th, 2011, 12:42 pm

I would check the work but the tools required to do that are something I haven't invested in yet, so I'll have to trust it's done well.

Just bought a set of the motion pro stud installers and man does that work nice! I've always hated double nutting the studs to torque them, and my stud Puller/installer from mac tools leaves three small indents where it grips the stud so I didn't like that either.

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Stop sign cylinder

Stop sign cylinder

Re: Stop sign cylinder