GX200 Questions

[RyanCR]

Hi guys

I am trying to remove the flywheel on a GX200 but its pretty stuck on there.

I have tried pushing it with a pry bar against the crankcase (very carefully) and then hitting the crankshaft end with a hammer but its not coming off, damaged the nut though

Any other advice?

Thanks!!

 

[RyanCR]

GX200 Rocker arms

Hi again

Sorry for all the questions, I 'm sure there will be a few more as I am new to all this

Only after I removed the rocker arms from my engine I realized that they are a different size? Tried to google but couldn't find much info.

Is this normal and am I correct in saying the smaller one sits on the inlet valve?

Thanks!

 

[Budget GoKart]

Sid should combine these into a thread called gx200 questions just use one thread for questions instead of all of these

 

[itsid]

yeah.. one 'project' one thread
makes it easier for us to give you a correct answer

Let me know what thread title you would like this newly merged thread to carry.

'sid

Budget, co-moderation is usually unnecessary

 

[RyanCR]

Thanks guys and sorry about that lol!

You can just use "GX200 Questions" as the title Sid.

Thank you!!

 

[itsid]

perfect.. Paul took care of that already

Now, back to the questions..

Never heard of a GX200 having different rocker arms lengths
so I checked with the GX200 parts manual I have (2004) and
both rocker arms on the GX200 have the same part number (14431-ZE1-000)
the valves and retainers are different but everything else on the valve train is identical IN to EX.

And to be sure I checked with a 2013 Lifan 168F manual (true clone)
and got the same result... valves and retainers are different, rest is not.

Maybe someone swapped one over from a different engine for some odd reason?

maybe a 'tuning' ratio rocker for the intake.. but I can't tell;
maybe a pic would help *shrugs*

flywheels if properly lapped to the crankshaft can get especially stubborn to remove if one forgets to add a tiny bit of copper grease and the mated surfaces can cold weld

A flywheel puller is the correct answer .. but one that's tough to give, since no man ever had one really
Second best imho is
persuation by rubber mallet and infiltration by some good quality penetration oil.
a gentle amount of heat for the flywheel by means of licking blow torch flame perhaps to speed things up.

But otherwise it's indeed oiling patience tapping, in repetetive patterns if you want to avoid brute force.

If you don't have a rubber mallet, put a pice of wood against the nut before you hit it with a hammer.
And make sure the nut is released enough to fully cover the initial threads on the shaft, you do not want to mushroom the threaded end

Any chance you have a welder laying around?
Then you might be able to make yourself a makeshift flywheel puller...

'sid

 

[RyanCR]

Hi guys, back again after some time with more questions.

There is damage on the crankcase where the head sits, can this be machined or will gasket sealer help? Can you put a thicker headgasket on if it has been machined.

I would also like to find out how to remove a rounded bolt on the connecting rod?

Thank you!

 

[Flyinhillbilly]

The block and head can both be machined, make sure to measure piston to head clearance and keep it around .025 or more and you’ll be fine.
As far as the rounded bolt goes, just do whatever it takes and replace whatever gets destroyed in the process. It’s not going to work like it is, so you have nothing to lose.

 

[BigWes]

My suggestion on your rounded bolt head, patience first, a well made six point socket next.

I'm trying to think, my wife is listening to awful pop music it makes my head hurt, I just recently took one of these apart, if I recall it should be a 10mm bolt and was torqued like 9' lbs.

So you may need to get a good mill file and dress up the flats on the bolt head. Take your time. Stay off the the rod cap with the file. Redefine the bolt head and use whatever size socket that will tightly fit after you get done even if it is a SAE socket just use a six point socket, bump it on if you need to. After you get that bolt out throw them both away and get new ones. Always replace rod bolts in pairs.

---------- Post added at 11:11 AM ---------- Previous post was at 11:07 AM ----------

If that doesn't work, take your mig welder and quickly tack a short bolt right on top of that worn bolt head without hearing up or burning your rod, and take it out that way...

 

[RyanCR]

The block and head can both be machined, make sure to measure piston to head clearance and keep it around .025 or more and you’ll be fine.
As far as the rounded bolt goes, just do whatever it takes and replace whatever gets destroyed in the process. It’s not going to work like it is, so you have nothing to lose.

Thanks so much for the info. Do you get "shorter" pistons then to compensate for the amount of metal you remove on block / head?

---------- Post added at 09:25 PM ---------- Previous post was at 09:24 PM ----------

My suggestion on your rounded bolt head, patience first, a well made six point socket next.

I'm trying to think, my wife is listening to awful pop music it makes my head hurt, I just recently took one of these apart, if I recall it should be a 10mm bolt and was torqued like 9' lbs.

So you may need to get a good mill file and dress up the flats on the bolt head. Take your time. Stay off the the rod cap with the file. Redefine the bolt head and use whatever size socket that will tightly fit after you get done even if it is a SAE socket just use a six point socket, bump it on if you need to. After you get that bolt out throw them both away and get new ones. Always replace rod bolts in pairs.

---------- Post added at 11:11 AM ---------- Previous post was at 11:07 AM ----------

If that doesn't work, take your mig welder and quickly tack a short bolt right on top of that worn bolt head without hearing up or burning your rod, and take it out that way...

Many thanks will give this a try

---------- Post added at 09:47 PM ---------- Previous post was at 09:25 PM ----------

Thanks Randy H!

 

[Flyinhillbilly]

Most of the time the piston will be .020-.030 in the hole to begin with. Step one is to measure it.

 

[BigWes]

Most of the time the piston will be .020-.030 in the hole to begin with. Step one is to measure it.

Exactly what Nate said...

This is a preventative measure done by the manufacturer to prevent the piston from contacting any part of the cylinder head due to tolerance issues or alignment issues in the manufacturing process...

And it's a good thing too...some of the manufacturing facilities do a poor job on their machine and cleaning processes...

To be honest it think it gives credit to the original design engineering of these little engines. For all their work just to be bastardized and half-assed or ran into the ground at 9 thousand RPM and still keep going, that says it all. I think those dudes had vision. Maybe they was sitting around the drafting table eating yakisoba and drinking Japanese beer laughing about what might happen if some American rednecks got hold of their fine Honda engine...who knows...it would make for a heck of tale if it was true!