Messing with my Aprilia Cup

did he also weld it?

 

yep

 

Finally pulled the trans this morning. I don't know what my problem was.



I don't know what I should be looking for besides any obvious damage. The screw holding the top oiler was damaged so it's probably been out before.

Nothing out of shape in the case.

 

I installed a thing this morning. . Output and shift shaft seals. Had to use the impact driver to get the screws out for the output shaft seal so I'm going to order hex head stuff from McMaster.



I watched a YT vid where a guy got the trans stabbed in first try. Dick. I can never get the oil pump drive lined up.

 

Check Fastenal first. If you are looking for standard stuff, your local store probably has them in stock, and if not, you can have it shipped there for free. They probably have the best selection of fasteners, and in most cases the prices are equal or lower than the hardware store.

 

My local Fastanal closed. At one time they were pretty good but the last time I went (years ago) the selection that was not lots of 25 was very small. Prior to that, they were happy (or at least willing) to break open packages. Then they switched to will-call only. They were not interested in walk-in business.

 

Trans installed this morning. Only took about 5 tries. Now I have to start doing the important stuff.

 

That is disappointing to hear. All of them near me are still actual stores with inventory and helpful employees. I usually order what I need online for instore pickup.

 

The 5 closest to me all show "This location is a Fulfillment Center with limited will-call hours. For availability outside of these posted hours, please contact the branch."

This reminds me I need to get a McMaster order in!

 

Rather than a McMaster order, I went with some bolt kits via Amazon. These are fasteners that are not under stress. They just have to not fall out. Both engines had blue locktite so I used some as well. Back together with a new gasket and countershaft seal.

These were all phillips head screws that required an impact driver to remove. Why do they do that?



I considered putting the crank in just for the hell of it but Ed actually sealed the bag he sent the crank in and I thought I might as well not open it until I'm ready. That, and it's just an opportunity for me to drop it or do something stupid. I touched up a few bits on the case halves with a file. Someone used a screwdriver to pry things apart at one time.

I'm staring at this pile of base gaskets that range from an aluminum (?) shim of about 0.3mm to a few in the 0.5-0.6 range, and a couple outliers at 1.3mm. A pair look to be OEM and they're 0.5-0.6, which is about what was on the engine already. I'm thinking I can set squish by assembling with used head gaskets, then do final assembly with new. This might be a terrible plan. I should probably do some research.

 

I’m with you. I’d probably mess it up somehow as the project drags on. You should always trust but verify (if you have the skill and tools to do so) but I’d probably leave it sealed in the bag until you’re ready to begin your initial assembly.

I’ve not done it yet myself. I’d think that a mock assembly will get you in the ballpark and allow you to understand squish and port timing and whether you have all the right parts or need to do more machining. But if your target is 0.8 mm squish band then you’ll still want to confirm squish upon final assembly. Having extra gaskets on hand is always nice just in case.

 

Not sure I didn't make a mistake in what you are saying, but I always reused base gaskets, until there was an issue, once I got my squish in the right area. If you were out here, I would be happy to sit in a chair and talk it over while you are rebuilding, but it sounds like you know at least as much as I do already. If you need an ear to bounce things off of or a facetime call, fell free to DM me. I love 2 strokes, but do not have any Aprilia experience yet.

Does the Aprilia use a paper gasket for the head, or an o-ring setup like our RS125 had? We could easily have the head off multiple times in one weekend and never have to change any gaskets.

 

OEM head gaskets are composite fiber media with metal inserts around the studs and cylinder bore. Aftermarket gaskets are usually similar but the devil is in the details. Some people convert their OEM heads to use o-ring seal or switch to aftermarket heads like TTW Cougar Red or VHM that are designed to use o-rings.

https://www.thetuningworks.co.uk/rgv-rs250-head-gasket-1mm

https://www.pjme.co.uk/acatalog/Suzuki-RGV-250-Head-Gasket-Athena--4123.html

https://www.thetuningworks.co.uk/250cc-rgv-rs250-cylinder-heads

https://www.vhm.nl/en/catalog/engin...s/cylinder-heads/aa33102/groups/g+c+a+nr+view

 

Conventional wisdom (I can't recall what the manual said) is that the stock head gaskets are one-and-done. As @freedomgli noted, they have copper crush washers embedded in them.

I hadn't considered re-using the base gaskets. I made no effort to 'save' them - they've been tossed in various spots. I think I feel better going new since I already have some.

 

I suck. I finally started assembling the engine today. I have to keep reminding myself that there's nothing I can do that a check to Steve won't fix. I pulled the relavent parts into my office because it's getting cold. Spent a bunch of time cleaning one of the dowell receivers to make the case halves go together cleanly by hand.

So, up for ridicule, here's how I ran the ThreeBond 1215:



Put a few drops of 2 stroke oil on the bearings and the bottom ends of the rods and bolted it back up. Torqued it all down. Ready to start messing with pistons and cylinders.

 

It takes a brave man to post pictures of his sealant application. I'd have slapped those two together as fast as possible to hide my sins

 

One trick I learned in the not-too-distant-past from a friend who's put together uncountable numbers of engines: get a 3-5cc syringe, fill it with sealant of choice, and use that to apply to the cases. Makes control of location and amount of sealant much much easier and way more even.

I'm cheap so I clean out the syringes when done (acetone works for most sealants) but come to think of it, the cost of the acetone and paper towels used for that process probably negates the cost savings of reusing the syringe.

Good luck with the next steps and can't wait to see this bike back on track.

 

In my view, that is pretty ugly for the sealant apply. But, what's done is done. I use my finger, or a piece of cardboard or popsicle stick to apply, and coat the whole of the sealing surface, and try to keep the thickness even, but minimal.

Assuming the crank spins freely, with a small amount of end play.

Once you get all the seals installed, and the cylinders on, just leak test it. If it holds, you are good, regardless of how ugly it looks.

Good luck!

PS you can use rubber bands around the cylinder studs to keep the rods centered. This will allow you to spin the crank without worrying about the rods hitting anything.

 

Tough love is the best love. I don't know why using my finger seemed like a Bad Idea. Rubber bands are a great idea.

I like the syring idea too @cyclox .

 

IIRC the trick is to wet your finger with acetone, that'll let you smooth the sealant out without it wanting to stick to your finger.