Gila Go BOOM!

Ahhh, so the story goes. Charlie and I drove up to malibu today, for the weekly Breakfast with Charlie series. Charlie drives himself and one or two other people to Malibu, we pull the peds out, rip 20 miles of amazing mountains and canyons, get breakfast at the rock store, and another 25 miles back.

We pull the bikes out of the truck, and right from the get go, my bike wasnt feeling right. Sounded weird, and wouldnt idle. My clutch was trashed, so I figured the no idling was due to that. The last time i rode the bike (about 2 weeks ago), it was shredding just fine. We start heading up the mountains and right away its not feeling good, low on power, wont hit the pipe going up hills. I decide to keep going since we headed all the way out there. I took it easy, not letting it rev out too high. We ride the first 20 miles and get to the rock store. We eat some breakfast. I check my plug, its lean for sure, but not TOO bad. I knew I shouldn't be riding it in the current condition, but continue. Make it through all the Mountains and canyons, and onto PCH headed back to out car. Wide open stretch. I thought we were only a few miles form the car, sick of dogging it, I open it up a bit more, shes cruising and finally feels like shes got some power, rode about 4 miles and.....POP. I knew what had happened. Charlie drove back to the truck, and picked me up.

Got home and opened her up. WOW.

Pulled the head off, and the head gasket had blown out. You can see from this pic where it had blown out at the bottom. Most of the seize marks are at the bottom of the cylinder, makes sense.

Now onto the weird stuff. Little hole in the piston. Doesnt go all the way through, but definitely some metal missing. What could cause this? Is timing the only possible issue? It doesnt look like other pistons I have seen with holes, where they are destroyed, with GIANT holes. This is small and not all the way through.

The biggest bummer. V-force reed cage (NOT CHEAP) destoyed. 2 of the 8 petals are broken/chipped at the tip. Dont know what could have caused this. These things are supposed to be super high quality. I dont think you can replace the reeds either. :( Any idea what would cause this?

Heres a few more pics of the cylinder. It should clean up fine. I have an extra piston, so I should be back on the rode. I am gonna port the shit out of it now. Super bummed on losing the reed cage though.

Re: Gila Go BOOM!

too bad. how old are the reeds?

Re: Gila Go BOOM!

Maybe 400 miles.

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is this the first time you've looked at the reeds? to me they it looks like normal wear and tear. but 400 miles seems pretty low. any idea on how many rpm's you're running?

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you totally can replace the reeds!

i know it doesn't look like you can because there's no screws etc but they actually just snap into place

Re: Gila Go BOOM!

That's good to hear.

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) Cupermcnewbster ( /


Maitland blew out his headgasket a few weeks ago when we were doing drag racing in santa cruz. Maybe they are faulty gaskets?

Re: Gila Go BOOM!

your piston would say you've been detonating too...

...probably caused by the air leak the head gasket caused and not your timing in less you changed your timing?...does the head look fine? i would say you've just been lucky and not been detonating long enough to cause a big hole

Re: Gila Go BOOM!

I blew up my head gasket too!

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i was thinking the same thing. running a little too lean from the head gasket leak. caused the little hole. i'd try a different head gasket or maybe even do a o-ringed head.

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pre-det timing issue?

ive never seen a hole that small though, beats me.

its a good thing gila's are going back into reproduction!

Re: Gila Go BOOM!

The cylinder is fine, and I have a piston, so n need for a new kit.

I just wasnt sure if an air leak could cause enough detonation to a hole in it. Glad to hear it can, cause I dont want to time my cdi again.

All the pistons I have seen with holes n them that were caused by timing had huge holes all th e way through.

Gonna order a new set of reeds soon and port the hell out of the cylinder and she will be back on the road.

Re: Gila Go BOOM!

🇮🇹💦 Of the Loin /

yeah dont use a headgasket. mill the heads and put em together.

or get a super strong headgasekt.

mine still idled and ran w/blown gasket (for like 100 feet) way to go gila compression!

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Hmm, interesting. I'll lose the headgasket.

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Why is everone using headgaskets?

What did we learn?

Less parts mean less parts to fail!

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What kinda material was the headgasket?

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Also how close was the piston coming to the sparkplug?

Small amount of arcing???

Re: Gila Go BOOM!

King Drunky JCams /

Wow. Makes me wanna take it easy on my Gila.

I need no drama with it...

I am completely open to running no head gasket.

Maybe I'll give that a shot.

Re: Gila Go BOOM!

tommy just drill out that spot on the piston and make it a speed hole... super fast

ur kit was trying to tell u that u needed it

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i've made small holes like that on pistons as a result of poorly timed set ups, infact i had a stock a35 jug with a small indent like that, and when the timing was checked it was way off, re-set the timing to stock specs and its been fine ever since,

you could also stack some washers on the spark plug to back it off a little ways,

i've actually had a few different pistons end up like that, as a result of to high of compression or/and ill set timing, a lot of the compression issues tend to also place the spark plug much closer to the piston, which is why backing the plugs out a little seems to help, a lot of the older 86cc v1 kits had similar problems i think, and needed a bazillion washers to bring the plug out

Re: Gila Go BOOM!

i blew out my head gasket on my stock fa 50 :S (no idea how that happened) soft seized skidded to a stop. piston was fine, sorta had lines going up and down it, a lot more than one seize can do :S i have only done one though so my guess is the previose owner who killed every thing else on the bike.

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yeah i never ever use head gaskets with aluminum top ends.

aluminum melds as long as you cross torque that shit, and you use a nice head with the gap ring around the compression zone.

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head gasket is good for me. hasn't blown out just got some head leaks every once in a while. solid as fuck.

tommy looks like you might have to time your bike again :(

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Head gaskets suck.

Buuuuuut. Gila has way too high compression and if you want to not blow up your shit you should get going on custom heads.

I'm running an O ring in a machined stock magnum head. I'm using Copper wire for the ring. Has not leaked in 700+ miles.

Your reeds look like I would expect from the way you use your moped.

My pistons look like that when my timing is advanced.


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o-ringed head FTW. didn't i suggest that earlier?

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🇮🇹💦 Of the Loin /

use the parma head.

i ran my bike through the hills for a solid 30 minutes.

my spark plug was able to be held in my hand and i could hold my hand on the head without a burn.

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The only mystery here is that 150.00 reed cage goin south...!!!It woulda grenaded at gender bender if it was timing...nice port work...Leefungchowhazelwood

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I was gonna say "Maitland should know all about this..."

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Definately detonation.

What octane gas are you running?

Check timing also

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Yeah, seems weird that it would be timing. IF that timing has been off for the last 400 miles, you think it would have done a bit more damage than that.

I always run 91.

I will have to look into this o-ring business. I dont like gettin all fancy like that (more so I dont like paying someone to get fancy for me).

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