installing freshly bored cylinder and new piston

[indianablaster]

first, i just got my cylinder back from ken o'connor racing and finally have all the other pieces i need to rebuild the top end.I:I Second, I have confidence that I can do this successfully, but this is probably the most mechanically involved (and most mechanically precise) thing i have ever attempted:-[. I understand everything that i have to do, i have watched ken's video about 30 times to make sure 8-| but if anyone has some time to give me any advice from personal experience with doing your own top end rebuild, much appreciated!!

here's a list of what i have:

freshly bored cylinder
wiseco piston w/ rings, piston pin, clips
vitos wrist pin bearing
cometic gasket set with cylinder, head, and reed gaskets

I was also wondering what peoples opinions were on using sealant where the reed cage meets the cylinder... this is where i had an airleak which would cause the rpms to hang and the engine run lean, and is probably what was the culprit that destoyed my original piston... before the piston went down, i tried to seal the leak with some red rtv? sealant some guy at some auto store said worked for him, but when i used it didn't stop the airleak entirely because the leak tester would still drop psi too fast, but was much better than before, so i decided to go with it and see if the rpms still would hang and they didn't anymore, so i made the wrong decision and went with it since i figure the leak is coming from the intake and i just went up a jet size, and one day while flying across a field the blaster lost power and was acting like it was going to die and i barely made it home... there's a pic of the piston... sorry for the rambling explanation of what happened but its hard to give you an accurate description of all that contributed to this happening... im sure that if i had done plug chops or tried to really seal the leak properly we might not be here, but i still wonder if something else might have contributed that i haven't considered... again just need some encouragement... also, i have learned my lesson and i want to do it right this time, no f@#$%# around I'll try and update with photos of the rebuild process

 

[Whitty21]

make sure u instal the wrist pin clips PROPERLY!!!!

 

[Zwiser]

make sure u instal the wrist pin clips PROPERLY!!!!

the proper way is to put them in with the open end facing up or down and in the groove all the way.

 

[Larry's Shee]

Make sure ALL gasket surfaces are clean, do not scrape them. Wash and dry cyl properly then oil cyl. Put one clip in piston before putting on rod, stuff clean rag around crank area while installing other clip. Use piston to square ring in bore to set end gap. Markings on rings go up. Marking on head gasket goes up. If you use RVT it MUST be fuel proof (gas). Plain old permatex #2 works good, I used Holimar (sp) on last build (couldn't find my threebond). OIL ALL parts well on installation. Torque cyl and head in increments and sequence per manual. Clean carb while it's off. Add gas and rip it. I:I

 

[indianablaster]

ok quick update.... just installed the piston but have a question... i checked the gap on the rings and everything is good, and the rings are installed correctly, but the top ring will slide right over the pin that is supposed to keep it in place, while the bottom ring won't slide over its pin and it stays in place... is this normal? i figure once the cylinder is installed and the ring is compressed it probably won't move around but just wondering... i know i have to keep the rings in place while i put the cylinder on but the top ring kinda worries me since it slides around easy...

also, i have a copper head gasket from cometic and it suggests gasgacinch sealant... would permetex high tack gasket sealant or the permetex copper spray a gasket hi temp adhesive sealant work instead? was thinking to just use the high tack stuff but the copper spray stuff sounds interesting... thanks

 

[NEONNIGHT34609]

that does not sound normal do you have a pic of what your talking about ? and i have never used any sealant on a head gasket but i do on the jug gasket. i like to use copper coat. and dont forget to clean your cylinder like ken says on his video.

 

[blasterdemon7]

What I did on mine was to use one hand to pinch the ring tight and the other hand to slide the jug on. Just pinch the ring shut and try to turn it to make sure the pin is in the gap. Make sure you fingers are on the side where the cut outs on the sleeve are.

 

[indianablaster]

this is a vid of what im talking about...

 

[kpnone]

The first top-end I did, I put the piston in backwards. A very expensive mistake. Make sure you can see the intake ports on the piston through the intake!

 

[blasterfreek30]

ok quick update.... just installed the piston but have a question... i checked the gap on the rings and everything is good, and the rings are installed correctly, but the top ring will slide right over the pin that is supposed to keep it in place, while the bottom ring won't slide over its pin and it stays in place... is this normal? i figure once the cylinder is installed and the ring is compressed it probably won't move around but just wondering... i know i have to keep the rings in place while i put the cylinder on but the top ring kinda worries me since it slides around easy...

also, i have a copper head gasket from cometic and it suggests gasgacinch sealant... would permetex high tack gasket sealant or the permetex copper spray a gasket hi temp adhesive sealant work instead? was thinking to just use the high tack stuff but the copper spray stuff sounds interesting... thanks

we use the same copper spray for the head gaskets..works great

 

[NEONNIGHT34609]

from the looks of the video your just spinning the rings on the piston and not squeezing them? either way thats not really the right way to do it. did you measure the ring gap in the bore first? are the rings "stepped" where the gap is to make room for the pin when there compressed?

 

[indianablaster]

^^ ye im not worried about it now... when i compress the top ring and try to move it, it stays in place, the rings are gapped properly (measured them in the bore) and they are stepped...

 

[NEONNIGHT34609]

then you should be good to go. the pins are recused in the piston to make room for the ring step to over lap the pin.

 

[indianablaster]

ok just wanted to update... got everything back togetherI:I did an airleak test and it was still holding 7 psi after 10 minutes so i was stoked... and omg i never knew that the thing had so much compression... well tomorrow im thinkin about taking it out to my moms property for the first few break in cycles before i have to go to work... i've got a 280 in the main right now... just wondering what u guys might start off with the mods i have listed... the bore is .070 over and i have the fmf pipe, no lid, regular carb.... super psyched though... gotta give rep to ken oconnor, blasterfreek, neonnight34609, and larry's shee (the permatex 2 stuff worked perfectly for sealing the intake)

 

[indianablaster]

ok this is probably a dumb question, but what gears should i be in when breaking the engine in... like should i just do the cycles in 1-3 gear... i understand about slowly increasing the amount of throttle you give each heat cycle, but just was gonna see if anyone had an opinion...

 

[jlsparky7]

How to vid in the link in my sig.

 

[blowncash]

Nice job !!! Its not too tough of a job. Just kinda nerving wanting it to be right.

 

[Awk08]

no driving it during the heat cycles, just sittin in nuetral lightly revving it till it's completely warmed up, then cool completely and repeat at least 3 times
then retorque your head and base bolts after the last complete cool down, and you'll be good,
then i like to do "NO/ZERO/NADA long full throttle runs" for the first tank of fuel

 

[indianablaster]

thanks for the advice awk, will do!

 

[indianablaster]

k so the blaster fired right up and idled, but i have some issues... not with the rebuild but the kill/keyswitch is not working to turn it off(recently removed the tors following jlsparkys instruction, so im not sure what i might have done during that to cause these to not work)

also, the clutch won't disengage (neutral works, and the cable is all good and pulls the little lever with the spring correctly) was thinking about changing clutch oil since it has sat for awhile, and getting a rolling start in neutral then firing it up and shifting into first to try and get the clutch loose so it will disengage and i can idle with the clutch lever pulled in ... any suggestions on these issues?

Thanks again for all the help! Blasterforum and ken oconnor racing ftw!!!!!