I need a piston lesson (NEW ? VALVES!)11/14/12

[MRSOUND]

Thanks shortline! Hopefully I can bring er back to life and give'er a makeover in due time. For now I need to see if I can her heart pumping again. Sure I'll be back with more questions and advice from anyone willing to chime in.

[oscarmayer]

take a measurement of the cam. see if in class they teach you abotu duration and lift ont he cam, if they do and it;'s not a stocker 90, then tehre's a decent chance it's th3e same motor. it does look liek it, the carb i thoguth was a 110 carb, but i could be wrong. The measure the inside of the intake, if it's bigger than 16mm it's the 125cc intake. (90 and 110 had same intake) it does look like a 125cc intake though. the best way is to pull the cam and check it on a cam machine to see what it says. (or check too see if it's stock markings). The reason why I'm asking is not only was it the last 90 that sam ever touched before he died, it was also the last "known" 110cc bigbore kit from rockeymountain they were able to find. i payed $145 for the piston back in 92 which is like shelling out about $350 in today's market for 1 piston. back then sinking $950 (which is what it cost me for the performance mods) was like $2500 today's market. That was actually the first trike motor I ever moded. Sam and I built it in the shop together and he taught me about the trikes back then.

anyway is you get a chance pull the head apart, check the valve seats, and the valves, if you see more than 1 angle on either one, that's another tall tale sign it's looking like it is the one we did. Not many peopel did them with multi angles.

I recommend trying to find anotehr "stock" jug and having it bored/hoend out to fit that piston. i think the 110cc piston rings with a slight "trim" woudl work on it but not 100% sure as like i said that was many years ago. if you can make it work, you'll have one hot rod of a setup that's for sure! At the river sand drags, it was the fastest thing under a 200cc bike (4-stroke). it out ran some 185s with upgraded carb and exhaust.

[MRSOUND]

Looking through the text book it does show how to measure the cam and valves but just to compare it to the manufactures spec. I already have the cam and valves disassembled, but not cleaned up yet. The cylinder bore and piston both look unscarred, just need "cleaned up". I only got .001 difference between them. Now that was using a telescoping gauge/c-mic on the bore. Wish I had access to an intramic for a more confident measurement, but fairly confident in my results though (10 yr machinist in previous career). I'll update dim. as I get them.
By the way I do have downloaded service manual to refer to thanks to you

[oscarmayer]

n/p sir! keep me informed, I'd love for this to be the actual engine. That way I know it ended up in a good home. See when we moved to texas in 95, I sold it to help pay for my first home along with my 185s. We didn't make that much $ on them but it did help witht he down payment which hel;ped start our lives off so it was a fair trade.

[MRSOUND]

Well I got to measure the cam tonight....stock 90 per the service manual. Sorry oscar i don't think this one was yours. Didn't get to clean up the valves yet but he did show us how to grind and lap them as well as redo the seats. Didn't get much shop time tonight. It's killing me! I want to get i tore down and back together! Anyway here's pic of the cam & head (still not cleaned up).

[MRSOUND]

Well here is before and after pics of my carb. This is a classic example i would assume of of leaving fuel in the carb for years. Still needs more cleaning as you can see. I do have a question on the slide. HOW DO I GET IT OUT? Soaked it in carb cleaner for about 1/2 hr. I thought when I unscrewed the top there would some way of releasing the cable. The instructor (more of a mower guy) thought everything should slide out. Is this true? What am I missing? Is it just seized in there? More soaking? Any help is appreciated!
Before

After

[shortline10]

Soak the carb in some mineral spirits over night and that should loosen the slide .

[MRSOUND]

Should it just pull out then? Not attached to anything else?

[shortline10]

Yes it will pull out .

Should it just pull out then? Not attached to anything else?

[Dirtcrasher]

Soak that puppy in gas for a bit, you did an amazing cleaning job on that carb!!.

[MRSOUND]

Soaked it in Gunk carb cleaner. Crap is expensive! $30 for a gallon can. But you do get multiple uses out of it. Even came with a basket inside so you drop your carb into the basket and let it soak (they recommend only 20 min). When time was up I just used a screwdriver to snag the basket handle and pull it out. Wipe down the outside with a rag and blew out the inside with air. Still need to go through all the orifices, Almost every one is clogged.

[86T3]

I used a bucket of that stuff on a real nasty 125M carb last winter. I pulled it out after 2 weeks and ran a wire through the fuel inlet and petcock inlets to get some on the crud out. After another 2 weeks it was completely free and clean. If i were you i'd throw it back in for a week or so. Also, the stuff i used (napa brand) said to wash it with water after you pull it out. Not sure if Gunk is the same. Good luck!

[TecateDan]

Make sure you do this step with a cigarette in your mouth for cool points

Soak that puppy in gas for a bit, you did an amazing cleaning job on that carb!!.

[MRSOUND]

Make sure you do this step with a cigarette in your mouth for cool points

Hmmmm...I do smoke but I think I'll pass on this tidbit of advise

[oscarmayer]

when i see these types of carbs, i will use the old "chemdip" it's a 1=gallon metal can you can buy at the auto-parts store of chemdip that eats it clean. soak the entire carb int he stuff over night and the enxt day it will be squeaky clean! even the palstic parts will be ok. then I take it and drop it into hot water to clean the cemdip off and sue carb cleaner to ensure all passages are clean. works like a charm and looks new.