Re: OLD BLUE,85 marathon re-construction
 

Nope I missed that one! OUCH! What if you got the new block cryo-treated first? I know in high powered car blocks they say it helps? :dontknow:

New Trend: Windmill powered gold cart... :lhmo:

Re: OLD BLUE,85 marathon re-construction
 

good thought jerm,but im bout tapped out money wise..
heres the best elec start block deal i could find,,it does come with new bearings and engine cover8)

http://www.ebay.com/itm/Launtop-13hp...c38f9b&vxp=mtr

here engine build thread;
http://www.buggiesgonewild.com/big-b...llet-beef.html

Hope you get it figured out...seems like a lot of $$$ just to get a gx390 back in the game.

Re: OLD BLUE,85 marathon re-construction
 

it did start out cheap remember:lol: it should be good a long time uness i kill it with high rpm,s..
at least i will have all these good parts an maybe move up to the billet flywheel someday if this goes well..its a learning thing..i will fix the block and bore the crap out of it for the future,2nd small engine full race build:lhmo:

i cant seem to find this answer online but id think the new block should be ready for the new piston and rings? anyone?
new block= newly machined cylinder wall and id think thats how there installed when new.right in the freshly machined hole..after cleaning of course..cant belive i cant answer this online..
screw it,im calling the machine shop:thumbup:

yep,could have had 2 complete 460cc clones for what i have in it now..def gotta keep it till the end now..

I would take the block and piston/rings to the machine shop to get them matched together. But if you have a micrometer or something else to measure clearances and feel knowledgeable enough...you can do it yourself to see if they match up.

After all the money you have invested I would think you want it done right. I don't have any tools to set up engine clearances...so I leave that to someone else!

Re: OLD BLUE,85 marathon re-construction
 

rest assured,,this is just my first time messin with a small engine..i have almost every tool i could ever need..been savin them for 30 yrs and have some i forgot what they were for :lol:
yes ive already measured every thing of importance and have those numbers wrote down..
actually,the reason im still going is i cant stop myself..once i start something and its not right i cant leave it alone..:mrgreen:
when the crank gets here today i will pre check the clearance with plastigauge i got from jegs,,if the billet rod has more than .003 oil clearance its going back as thats what i want,,or,the crank will get turned to my specs and i will get a .010 under bearing from arc...
crank bearing clearance in real world is .003,and not over .004 and not under .002,,,i will settle for 2-3 but 4 make me wanna cringe,but then again it ran sweet with7-.008 and knocking:shock:
im only gonna be so picky now because i have went past what i was going to do because the po did a crappy job imo..i still want basically stock just dependability for a couple yrs..then again these motors are kinda fun:thumbup:
the small port and polish to the head will /should amaze me my dad thinks..pics in motor build thread.

Re: OLD BLUE,85 marathon re-construction
 

got the clutch back together with new helix.
http://www.buggiesgonewild.com/gas-e...tml#post875403

That sucks about the motor. Sounds like it going back together soon. Good luck!

Sent from my SGH-T999 using Tapatalk 2

Great news man...can't wait to see it fire up again!

Re: OLD BLUE,85 marathon re-construction
 

if i can get it running half as good as yours,bansheemxer,i will be happy..:thumbup:
crank never showed up so should be here today..block maybe by sat8)

Re: OLD BLUE,85 marathon re-construction
 

You'll be spinning tires and jumping rocks in no time.

Re: OLD BLUE,85 marathon re-construction
 

With his luck he'll knock a hole in the new cases. Think I'd start slow and work my way out.:lhmo::lhmo::lhmo:



LOU

Now don't get all negative! If we keep talkin like that Sassy might get leery of romping on the go pedal once it gets back together! He has way more invested than I do in my engine...but it will be worth it in reliability. !:thumbup:

Re: OLD BLUE,85 marathon re-construction
 

plus i will always have these parts for future engines i may screw up lol..
just got the crank and it mics out perfect,but it needs polished imo,so,in the am i have the hole day to myself and will plastigauge and hope and pray that the clearance comes out on the low end of clearance specs.002-.003
so i can give it a shine so it will be slick as owl snot and last a long time..
and i no,,this is not a procedure for the faint at heart when it comes to engines,because it should really be done on a polishing machine or lathe..im hoping the rods is tight enough so i can at least polish 1 thousandths off the journal and i will do it the only possible way to get it as true as you can by hand..
not with a dremel tool or a polish cloth..:mrgreen:
i havent done it in so long i feel i should pactice on the old crank and take it down a few thoudands then it will be a .010 under crank,:mrgreen:and will have a spare..of course the practicing will be too see if i can keep it true and round also:shock: i dont wana do much at all on the new one8)

then after this i will lap the flywheel to crank for 5 minutes:wink:
wish me nothing but patience and luck:help:

Re: OLD BLUE,85 marathon re-construction
 

Good luck bud.

Re: OLD BLUE,85 marathon re-construction
 

my luck gets worse:mrgreen: if following the engine build thread in my sig you will see if it wernt for bad luck id have no luck at all..good thing i have a unique set of skills or id really be out of luck.
started assy of the new engine today..went to slide the piston and arc rod in and the block swallowed it,wtf.
to make a long story short,the ebay member sent me a new 420cc clone engine and not gx390..im so pissed we wont even talk about it..
i told ebay member i would have to send it back because my crank and piston wont work,,he says he will send a new crank,piston assy for the motor for free..i just wanted a return but i guess if he sends me the crank and piston i will just put together the 420cc and still have parts to get the gx390 going in the future also..
so now i gotta find out 420cc info and theres not near the parts out there that there is for the gx390..
anyone no if my gx390 head will work on the 420cc clone?

good thing im not in a hurry any more..someday i will be smoking v twin big blocks:lhmo: prob because the rings didnt seat my luck,and the valve seals go bad at the same time:roll:

Re: OLD BLUE,85 marathon re-construction
 

Whoa man. You've had some seriously bad luck man. So basically you were supposed to get a real Honda and the seller didn't think you would know it was clone? So you're going to throw the clone in for now and start building the GX390...I say throw a turbo on it lol.

Re: OLD BLUE,85 marathon re-construction
 

it was advertised as a "launtop gx390 replacment engine block" ive learned since that all "launtop"brand engines are 420cc ..gx390 replacements bored and stroked to the 420cc..
hope the free crank and piston assy works out now..and yes i could have a gx390 also someday when i get a spare engine..what a pita..

Man that sucks! I seem to be having the same kinda of luck lately. I hope it get better for ya.

Sent from my SGH-T999 using Tapatalk 2

Dang man...when it rains it pours! I hope you have better luck with the clone block.

Re: OLD BLUE,85 marathon re-construction
 

mortons salt"when it rains it pours":thumbup: did i win the free shopping spree lol...my mother actually won a 2 hr spree with that exact question when i was a kid..kinda cool memories 8)
one good thing is i have some new gauges and mac click style 3/8 torque wrench to go with some digital calipers i just got,and a set of telescopic gauges,and a will have a 2 inch micrometer on the way soon to double check the double checked work the 3rd time:lhmo::lhmo:
i dont trust cheap tools useually,but the 10.00 dial calipers i :lhmo:ot 5 yrs or so ago are dead on the money within a 1/2 thousandth up to 6 inches,for anyone needing a pair and doubts them like i did..
in the beginning i didnt say much as i figured i may have poss measured wrong,but 2 people and 4 different tools cant lie i suppose:thumbup:
i actually will be calling plastigauge to see if i can send them back this green strip so they can check it and if they tell me it was off then thats great and there honest..if they tell me it is within spec and nothing wrong with it i will tell them there full o shizzit..



the ebay member has not let me no the parts shipped so im kinda gettin worried,as i been all over the web for 2 days and can not find a 420cc crankshaft with a 1inch key anywhere..even on flea bay..
im sure parsons or nrracing can get them but there marked up a hundred b ucks almost..
i did read somewhere the 420 cranks were forged last night but that has to be wrong or the engine couldnt sell that cheap id think..

Glad you're doing all this leg work for us! :thumbup::D but seriously, good info to know if I ever run into problem with my motor in the future. Hopefully and surely you're persistence pays off. I'll quit talking about it so as to not jenks you. (No pun intended since I actually LIVE in Jenks Oklahoma! :D)

Re: OLD BLUE,85 marathon re-construction
 

thanks banshee8) jenks oklahoma,,who woulda thought:lhmo:
havent heard from the ebay guy since fri,,hope he lets me no something by tues as im getting tempted to just put the darn other block back together,or get this one decked to be a gx390 and not a 420..i found a stock cam for the 420 for 25 bucks iirc and a balance shaft for 20 bucks but cant find a crank no where..maybe he is having the same problem:roll:
too much time and mulla in parts taking up the welding table,when i could be making money on that table stinks..

Re: OLD BLUE,85 marathon re-construction
 

got tired of waiting and figured i will never hopefully hav much buggy down time in the future..
the parts for the 420 block i have will be shipped in a day or 2 im told

now i will have plenty of parts that interchange anyhow..gonna strip the hf motor down,remove the gov and cut crank"if needed "and run it like i stole it after the break in, and see if it will turn 5000 rpms dependably for a yr:thumbup:
i will keep all the original parts in the box just incase..and be able to quikly swap engines and spend a lil time perfecting the one im building..prob will go ahead in a week or so if funds allow and get a cam for the other engine also..just so when i swap motors i can feel a mayjor difference:mrgreen:
a buddy of mine wanted a pea shooter i had bad,so i let him have it and went and got the extra engine,,well actually kinda the 3rd:lhmo:
http://i1090.photobucket.com/albums/...psd72fa4c8.jpg
havent checked but im hoping the high altitude kit has a bigger jet in there
http://i1090.photobucket.com/albums/...psace769b9.jpg
http://i1090.photobucket.com/albums/...ps69aa4694.jpg
http://i1090.photobucket.com/albums/...psa64ee7aa.jpg

Re: OLD BLUE,85 marathon re-construction
 

i have read places that people wanting to put gx390 parts in there 420cc engine and find the cam bearing machined in the blocks are .008 to big..just wanted to say that the "launtop"brand block is dead on with the gx390 blocks and all is the same except the 2mm more bore and stroke:thumbup:
i cant speak for the predator hf engine yet but ive read there dead on correct with the gx390 also far as cam bearing area..
the new block i have looks better then this new hf engne also as to the way it was casted in the mold..they both look as good or better than the honda tho imo..i read the hondas are forged blocks but i dont belive that at all as it broke too darn easy8)

Re: OLD BLUE,85 marathon re-construction
 

Nice bud. I thought HF wasn't carrying the 420 anymore...

Re: OLD BLUE,85 marathon re-construction
 

i read a lot of reviews and herd that but they all still have them listed..had to drive a hundred miles to find one in stock tho:thumbup:
there cheaper on line if you have it shipped,,only 7 bucks or so shipping,and they may not charge you tax but im not sure bout that..

Re: OLD BLUE,85 marathon re-construction
 

I'm sure you're just itching to get some ride time in sassy!

I've had good luck with my 420, and it has plenty of torque to climb over some fallen trees on my trails with 3 grown men on it:mrgreen:

Re: OLD BLUE,85 marathon re-construction
 

thanks dan..im going crazy just not gettin in the woodz as often as i like..like every other day8)
i was extremly happy with the gx390,,the power difference i was used to blew me away..by the feel of the compresion in this 420 i think it will surpass the gx390:thumbup:
i will def try hard to not go over 200-2500 rpm,s till after the first 3 hrs it recomends i suppose..
dan,how high of rpm,s have you takin it? your gov removed?

i was gonna run it on the bench and such and decided to just go for it..
stripped off all its clothes...sitting in its underwear waiting for the gov to be removed on the inside..

incase anyone with this engine has a annoying rattle,,this extra throttle cable thingy is so loose it drove me nuts just unhooking the linkage,but its made that way it seems
http://i1090.photobucket.com/albums/...psbf8868f3.jpg
warning;the next pic is a naked engine
http://i1090.photobucket.com/albums/...ps02c9179b.jpg

http://i1090.photobucket.com/albums/...ps575c7462.jpg

http://i1090.photobucket.com/albums/...psc3e5f3af.jpg

Re: OLD BLUE,85 marathon re-construction
 

She's a beauty!

Re: OLD BLUE,85 marathon re-construction
 

I still have my governor in, so I imagine I am not exceeding the 3500 or so rpms on this bad boy:lhmo:

With 22" tires and a belt that is 2" too long(which is killing my top speed) I can get up to 26mph gps by myself. I'm hoping to get a shorter belt this week and get into the 30s:mrgreen:

Torque is the main thing with this 420. I am very pleased with how easily it can break the tires loose on dirt or gravel:thumbup:

Re: OLD BLUE,85 marathon re-construction
 

thats good to no,as i love to burn out now and then:mrgreen:.then the other one im building will prob be in the 45-50 mph range when its done so it should do a donut real good someday:thumbup:

well fellas,i still can not catch a break..got the new 420 ready to install and the darn tapered clutch adapter from cpp wont work with my 2 stroke clutch:roll: always something..the wife is real happy:help: so now ive gotta wheel and deal a little while to get the extra cash for a new clutch..
dont get me wrong,i want a new clutch,but wasnt planning another few hundred at this time..oh well im in no hurry now:lhmo: i thought these things stopped happing to me 15 yrs ago lol..i guess it comes in streaks,haha

this is what your new engine looks like when purchased:shock: not bad but glad to get it out and cleaned for the next 3 hr break in "someday":mrgreen:
http://i1090.photobucket.com/albums/...ps89eb2fba.jpg

there is about a half a cup of this in there when i opened it..not as bad as it looks tho..
http://i1090.photobucket.com/albums/...ps19a52364.jpg

just to set the record straight,these 420 predators have the exact same cam journa sixe as the gx390:thumbup: and only a few thousandths or less clearance when new
http://i1090.photobucket.com/albums/...psbb40a58e.jpg

ser number of the 2mm stroked crank
http://i1090.photobucket.com/albums/...ps3c7f6b0a.jpg

ser number of the cam
http://i1090.photobucket.com/albums/...psd27e00ef.jpg

time to torch out that gov,and blow a extra breather hole in the rear of the block:lhmo: not really
http://i1090.photobucket.com/albums/...ps754e0e36.jpg

Re: OLD BLUE,85 marathon re-construction
 

cut the shaft half way thru and snap off with pliers
http://i1090.photobucket.com/albums/...psaeb9068a.jpg

heres what your left with,,like said before its easyer to break it off the shaft..
http://i1090.photobucket.com/albums/...psd92ba7ae.jpg

taped hole for fuel pulse line
http://i1090.photobucket.com/albums/...psf82c190c.jpg

covered back up till i can get a clutch
http://i1090.photobucket.com/albums/...ps40c43edf.jpg

was 60 bucks shipped,sell for 40 bucks shipped..will run add on here tonight
http://i1090.photobucket.com/albums/...psdaffd543.jpg

http://i1090.photobucket.com/albums/...psa29d7918.jpg

Re: OLD BLUE,85 marathon re-construction
 

Looks like you've been real busy. Best of luck on finding what you need.

Re: OLD BLUE,85 marathon re-construction
 

well i sold the adapter to a bgw member thankfully..well after much searching and talking to people i decided on the comet 94c clutch thats fully adjustable and set up for a cart..on the truck from indiana..hope to get it by sat would be sweet.
a lil suckin up to the wife didnt hurt either as far as spending even more hard earned cash..well plastic works too:thumbup:
i heard comet factory was out of the 94c model 206095a for a few months and a few places are out..theres also a few places that have a bunch.. i found mine ..220 bucks shipped:thumbup:

Re: OLD BLUE,85 marathon re-construction
 

Good to hear.

Re: OLD BLUE,85 marathon re-construction
 

got the new 420cc in and bolted up,,ran it a half dozen times with breaks in between..seems to have plenty of power and pretty peppy:thumbup:
clutch is still in indiana tho..

Re: OLD BLUE,85 marathon re-construction
 

Post up a video. Love to see what that motor does.

Re: OLD BLUE,85 marathon re-construction
 

Looking forward to seeing that video.