Franken engine

Big Red · Aug 9, 2011

Malanca said:
the past few days i've been doing a little here and there..
bottom line is got the bike running for a block but it was only going at 5mph or around there it was pretty slow. (I HAVE NO IDEA WHY ANY INPUT ON THIS?)
few times before that it would stutter a bit like it would wanna turn on but after a few seconds it would just die out.

the whole cylinder to piston size wasn't cooperating because i forgot to put on those metal gaskets right before the head. so i added 2 extra homemade ones and thats when it started to run for the distance of the block like i mentioned earlier..

after that it just died out slowly and it wouldnt turn on anymore after that.
an uncle of mine told me its most likely the timing.
I have checked for spark (got a small orange one) the bottom half is a brand new engine so i doubt its the magneto or the CDI since its emitting spark.

any input / suggestions / ideas how to get my bike back and running.

i will post pics later on. my bike is a little modified with a strange new expansion chamber (i havent been able to test it out yet! :/ )
and i got a seat post that leans pretty low

Four head gaskets = low compression = 5mph.

HeadSmess · Aug 10, 2011

Malanca said:
Frankenstein (p) gave me a top half of a spare engine he had lying around..

i think i can see your problem... exact condition of the cylinder bore?

the rings arent seating/contacting the cylinder wall evenly. usually happens after taking them off and then putting the top at the bottom and bottom at top...

cylinders warped, and once again, rings just arent sealing. hand in hand with above at times

chromeplating has gone. usually results in an engine that starts nice, runs great then carks it...til it cools down the starts great, runs fine then carks it til it cools down ad nauseum... until final complete death.

head gaskets make a squeaking sound usually... depending on size of the leak. or you can feel the leak

im finding my slant plug head leaks on the plug side, no matter what i do...

i recently just ran a 3.2 mm head gasket, with little or no noticeable difference in performance, even with a dirty great pipe on it... now on a 1.6.

the engine came with two fitted

about 1mm? 0.7 after squashdown..

oh. last and least! bottom cylinder gasket is very important

got one? a new intact one with nice flat mating surfaces? thats around the right way?

Malanca · Aug 12, 2011

I've come to the conclusion (or just stupidly guessing) that my cylinder isnt matching up to the correct size in height. (something motorpsycho said from the start)

Big Red i took all but one gasket off..and when attempting to see if it would turn over. it would just lock up..so i went back to the 4 gaskets and when attempting it would turn over.

i got the engine off thatsdax or something like that...when talking to the them over the phone they said it may or may not fit with whatever parts i have.

HEADSMESS: The cylinder is perfectly fine on the inside. the piston rings are brand new and are the correct size. there are brand new gaskets on all parts of the bottom engine. the only ones that were hand made out of gasket paper and sealant were the ones for the head.

(some minor details that i never put into this thread but happened)
1. i didnt have a muffler the whole time when attempting this, but today i put on my expansion. i didnt see a difference or think it would because i ran a previous bike with no exhaust for a few months.
2. it appears my gas isnt flowing from the tank thru the gas hose?
I have a clear gas tube and only half the hose has gas and i have a full tank...but when i remove the hose the tank begins to release gas.
3. I have 2 heads...ones a normal one where the plug sits straight up and the 2nd is a slant one...the slant one belongs to the cylinder thats on...but i have the straight one on it as of now because it seemed it had more room. (mistake using that one??)
4. would the throttle have anything to do with this? i've adjusted the screw on the carb as well as the IDLE screw.

any last minute things anyone would like to put in before i decide to order this top half from the site i got the bottom engine from.
I'm going to post pics in about an hour

Malanca · Aug 12, 2011

Big Red · Aug 12, 2011

engine.

Hey Malanca,
I don't know if anyone asked this yet? Are you SURE that you have the correct spark plug? If it reaches too far into the cylinder it will contact the top of the piston. Next time you pull the head look to see if the plug extends very far below the head dome. Will it turn over without the spark plug in it?
Just something to look at before you order a new cylinder.
Also, make sure ALL gaskets are the correct gaskets. A homemade gasket will not have the same thickness of the factory gasket. The clearence on these engines are very closley set, so don't mess around with homemade stuff. The entire gasket set is only about $10.00. Heck, I'll mail a used head gasket to you just to use for mock up. It would at least be very close to what the clearence should be. If I have a new one, (I'll check tomorrow) I'll just give it to you. You can't really just "make" a head gasket out of "stuff".
Anyway, you didn't say if the engine would turn over WITHOUT the spark plug in. So I'm real curious to know about that. Go back to one head gasket, the correct one, and leave the plug out, see what happens. Checking that you have the right spark plug is free. A "cheap" cylinder is about $25.00 + shipping.
Thanks,
Big Red.
.P.S. Looks like air in the gas line is normal. Trust me, It fills the carb bowl just fine.

Malanca · Aug 13, 2011

yes its a new spark plug...one brand i've always used, but i also had one of the spare ones that comes with the kit..(brand new too) tested it on it as well..
even used a new CDI

spark plug to dome..theres still some clearance between that and the piston.
I can load a pic of it.

Engine wont turn over with the plug in it. ( i havent really payed attention if the piston moves, the bike either just freezes up in its tracks when i walk with it) or if i ride it and try to turn it on the bike starts to lose momentum when the clutch is engaged.
with out the plug. all i can hear is the piston move up and down. i would walk with the bike and the clutch engaged. (dont know if thats the proper way to turning over and engine with the plug off. ) i would use that trick to kill some gas when the engine overfloods.

thanks for the gasket offer. i just got a set in the mail today i pre ordered it a week ago incase it would be the problem. much thanks Big Red

it just stumps me that i had it almost running at a low speed and i'm no where near that now.

Big Red · Aug 13, 2011

Engine

Malanca,
Looks like yer gonna order the new jug. When you get it in measure both, old and new, to see the difference. If there is it would be something new I have learned. I REALLY thought the chinese factorys went off the same specs when making these engines. Then the only difference would be quality control. Quality, in a chinese engine? Thats almost a joke that ain't really funny.
I think once you get the spacing problem solved you'll be OK. Let us know how it works out. Like I said before, Too much space between the top of the piston and the cylinder dome = low compression = 5mph. Too little space = hitting the head (or plug) with the piston or TOO MUCH COMPRESSION and risking blowing the head off the engine, Blowing a head gasket or stripping out the head bolts. Keep in touch. We're not giving up on this yet.
Thanks,
Big Red.

Malanca · Aug 13, 2011

I dont blame ya I thought the exact same thing when I ordered it. I kept thinking yeah yeah yeah its gonna fit they're all the same. the guy in the phone told me it was a D-model engine. and said there was a different kind as well...i thought he was talking about the kind with the pull start.

but yes i will let everyone know about the sizes when i get it..now to order it

Franken engine

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