Re: Eurokit hot and slow

^ that’s a thought. I was struggling with weird WOT runs and ended up being clogged fuel cap vents.

Re: Eurokit hot and slow

> Totally normal JBOT wrote:

> -------------------------------------------------------

> Just cut the hose on a long hose tester and use hose clamps to make as

> short as possible.

>

> Are you sure you’re flowing fuel well?

>

> Clogged petcock or filter will cause running hot issues cuz the fuel

> just doesn’t flow well.

That would work but I don't really wanna cut up my only compression tester. I'll keep looking for a shorty or pick up another one to try that at some point in the future.

Fuel is flowing as good as I can tell, the filter rebuildable and I cleaned it recently. The tank is coated but I can pull the petcock to be sure. Good idea on that!

Re: Eurokit hot and slow

> Papa _ wrote:

> -------------------------------------------------------

> ^ that’s a thought. I was struggling with weird WOT runs and ended up

> being clogged fuel cap vents.

Also an interesting idea. I can try running with a loose cap as well.

My next big idea is to run an air filter. I tried it before but my jets are too rich at the smallest with the filter to really peak it out but if I have any other odd ball lean conditions it should richen those up. I've got some smaller jets on order to see what that does.

Also I feel I should mention I'm running 91 E10 with a 50:1 ratio of some old Valvoline 2 stroke I had and a B8HS gapped to around 0.5mm. I've got some Dominator on order in case that will help and I'm going to try and find some non ethanol gas as well but that would be such a pisser if that is what actually fixes it as its really hard to come by here.

Re: Eurokit hot and slow

Most long hose compression testers still have the Schrader valve in the screw in dingus so the hose length doesn't actually matter. Mine is from Amazon, sunex maybe or one of those higher end Taiwan brands? I don't really think compression test is going to tell you much.

Normally oil doesn't matter that much but since it's actually burning on the face of your way too hot piston, it's a problem for your setup. Conventional 2t tends to break down around 350 cht , synthetic like dominator will let you run out to 400+ depending on the setup. It's not causing the problem though, it's more of a symptom, but it could have contributed to piston/ring damage that is causing the problem.

Since timing doesn't change things much, it's really looking like you have an air leak somewhere. If your piston rings never broke in correctly because your tune was off to begin with, they might be toast or your piston itself might be hosed, that will act like an air leak because combustion gasses are blowing down into your crankcase.

It's probably worth splitting your cases again and resealing them. Get everything super clean and Pay special attention to where the case split and the base gasket all meets up on the edge of the transfer ports. I've found that it's usually way easier to just rebuild a problematic engine in 2-3 hours than spend weeks trying to tune it piecemeal.

At the end of the day if you don't have good ring seal, you're fucked. It's never gonna run right. Seeing those streaks in the bore and how crusty that piston looks from the top, I'm gonna bet that's at least part of the problem.

Re: Eurokit hot and slow

🇮🇹💦 Of the Loin /

There's only one ring on this kit if it's the same one I have.

What's your head gasket made out of?

Re: Eurokit hot and slow

Totally normal JBOT /

The Schrader valve is in the part that screws into the cyl, the pressure gauge is at the end of the long hose. The long hose effects pressure readings greatly on lil baby cyl. Easily 20%

> Graham Motzing wrote:

> -------------------------------------------------------

> Most long hose compression testers still have the Schrader valve in the

> screw in dingus so the hose length doesn't actually matter. Mine is

> from Amazon, sunex maybe or one of those higher end Taiwan brands? I

> don't really think compression test is going to tell you much.

>

> Normally oil doesn't matter that much but since it's actually burning on

> the face of your way too hot piston, it's a problem for your setup.

> Conventional 2t tends to break down around 350 cht , synthetic like

> dominator will let you run out to 400+ depending on the setup. It's not

> causing the problem though, it's more of a symptom, but it could have

> contributed to piston/ring damage that is causing the problem.

>

> Since timing doesn't change things much, it's really looking like you

> have an air leak somewhere. If your piston rings never broke in

> correctly because your tune was off to begin with, they might be toast

> or your piston itself might be hosed, that will act like an air leak

> because combustion gasses are blowing down into your crankcase.

>

> It's probably worth splitting your cases again and resealing them. Get

> everything super clean and Pay special attention to where the case split

> and the base gasket all meets up on the edge of the transfer ports.

> I've found that it's usually way easier to just rebuild a problematic

> engine in 2-3 hours than spend weeks trying to tune it piecemeal.

>

> At the end of the day if you don't have good ring seal, you're fucked.

> It's never gonna run right. Seeing those streaks in the bore and how

> crusty that piston looks from the top, I'm gonna bet that's at least

> part of the problem.

Re: Eurokit hot and slow

Totally normal JBOT /

Ditch the rebuildable filter and run paper.

It’s the best option for all mopeds.

So much rust in moped tanks and the screen filters or sintered bronze don’t catch most. Paper catches almost all debris.

It’s amazing how easy it is to catch garbage in jets or float needle that will shut you down on the road.

Re: Eurokit hot and slow

> Totally normal JBOT wrote:

> -------------------------------------------------------

> The Schrader valve is in the part that screws into the cyl, the pressure

> gauge is at the end of the long hose. The long hose effects pressure

> readings greatly on lil baby cyl. Easily 20%

> .

Hmm, theoretically that shouldn't matter but I can't say I've ever actually tried it back to back.

The Schrader valve one way action should allow the volume of the hose to 'pump up' like an air compressor so after a few cycles it will balance to the max pressure developed in the head chamber. The compressed volume is only going to be whatever is on the cylinder side of the check valve so it will give an accurate measurement.

I have a long hose and I get what I think are accurate compression readings but I really don't use it for tuning or setting up cylinders.

Re: Eurokit hot and slow

up shits creek /

I'm with graham on this one. Mines longer and it takes more compression cycles to get to what I believe is accurate. When the pressure gauge stops going up you have ur psi reading is how I've always read it.

Re: Eurokit hot and slow

> up shits creek wrote:

> -------------------------------------------------------

> I'm with graham on this one. Mines longer and it takes more compression

> cycles to get to what I believe is accurate. When the pressure gauge

> stops going up you have ur psi reading is how I've always read it.

+1

Re: Eurokit hot and slow

> Graham Motzing wrote:

> -------------------------------------------------------

> Most long hose compression testers still have the Schrader valve in the

> screw in dingus so the hose length doesn't actually matter. Mine is

> from Amazon, sunex maybe or one of those higher end Taiwan brands? I

> don't really think compression test is going to tell you much.

>

> Normally oil doesn't matter that much but since it's actually burning on

> the face of your way too hot piston, it's a problem for your setup.

> Conventional 2t tends to break down around 350 cht , synthetic like

> dominator will let you run out to 400+ depending on the setup. It's not

> causing the problem though, it's more of a symptom, but it could have

> contributed to piston/ring damage that is causing the problem.

>

> Since timing doesn't change things much, it's really looking like you

> have an air leak somewhere. If your piston rings never broke in

> correctly because your tune was off to begin with, they might be toast

> or your piston itself might be hosed, that will act like an air leak

> because combustion gasses are blowing down into your crankcase.

>

> It's probably worth splitting your cases again and resealing them. Get

> everything super clean and Pay special attention to where the case split

> and the base gasket all meets up on the edge of the transfer ports.

> I've found that it's usually way easier to just rebuild a problematic

> engine in 2-3 hours than spend weeks trying to tune it piecemeal.

>

> At the end of the day if you don't have good ring seal, you're fucked.

> It's never gonna run right. Seeing those streaks in the bore and how

> crusty that piston looks from the top, I'm gonna bet that's at least

> part of the problem.

Yeah I figured it might be the ring so I've replaced it recently and rehoned the cylinder. If you're saying the bore looks worn with the pictures I posted thats bad though. The piston looked ok without any scoring on it but I didn't take a picture last time I had it apart so I don't know for sure. I'll rebuild it whenever I get the seals in and maybe throw some gasket sealant between the bottom base gasket and the case.

> 🇮🇹💦 Of the Loin wrote:

> -------------------------------------------------------

> There's only one ring on this kit if it's the same one I have.

>

> What's your head gasket made out of?

Some time of metal? Maybe aluminum, I've sprayed it in copper head gasket sealant.

Air filter didn't make any difference. Odd that it ran cool for a single rip at the beginning of this thread after spacing the base gasket. I wonder if my cylinder or piston is just a dud somehow.

Re: Eurokit hot and slow

super_sketchy_leak_down.jpg

Big news. I found an air leak. I built a little diy leak down tester and there is a strong leak out of the top drivers side (I guess they're both drivers side) head bolt. Super weird is that if you flip the base gasket it still leaks out of that one, same if you flip the head or flip the head gasket.

Anyways I got something to work off of for now. Also I've got some pictures of the piston but honestly it looked this bad before I replaced the ring.

piston.jpg
piston3.jpg

Re: Eurokit hot and slow

Ahh ok never mind the piston is probably good, the ring its hard to tell from pics , but probably ok at least not bad enough to be causing the problem.

It looks like the gaskets are pushed up around the studs, that is a big no no, you need to get a nice sharp xacto and cut them super clean and perfect.

The double gasket is always dicey, if you're gonna do it might be a good idea to use a thin smear of goop.

Re: Eurokit hot and slow

Totally normal JBOT /

Yeah never double gasket

Re: Eurokit hot and slow

> Graham Motzing wrote:

> -------------------------------------------------------

> Ahh ok never mind the piston is probably good, the ring its hard to tell

> from pics , but probably ok at least not bad enough to be causing the

> problem.

>

> It looks like the gaskets are pushed up around the studs, that is a big

> no no, you need to get a nice sharp xacto and cut them super clean and

> perfect.

>

> The double gasket is always dicey, if you're gonna do it might be a good

> idea to use a thin smear of goop.

If it's just bad base gaskets I'm going to be so glad. Easy fixes are the best fixes.

I did order the spacer that Jackerz! Mentioned before but who knows when it'll be here. If I run the 1mm spacer liquid gasket sealed to the case and then a .7mm gasket that should give me the same spacing as my stack-o-gaskets (tm).

That also explains why it worked for a short bit after adjusting my spacing as it was all new gaskets and then they just gave up or got soaked through and sunk or swelled or who knows.

Re: Eurokit hot and slow

Use 2x .35 gasket material and a 1mm spacer. Or only use the metal spacer and motoseal. Never smear that shit on paper, it just makes a mess when you go and take it off again and it usually doesn’t cure properly when applied to paper anyways.

Re: Eurokit hot and slow

I use HighTack anytime I have doubts about sealing surfaces or gaskets . Excellent stuff .

Re: Eurokit hot and slow

Also I don't know what studs those are or if they are good but make sure you are torquing the head nuts and torque them again after a few heat cycles. I always use stock puch studs since they have a rolled thread and are a very good high tensile steel.

Do 7 ft lbs, if you don't have a torque wrench the 1/4" click one from harbor freight is actually pretty decent.

And clean up all that old sealant, make sure all the gasket surfaces are super clean and nothing is hanging up.

Re: Eurokit hot and slow

Totally normal JBOT /

> Daniel '' wrote:

> -------------------------------------------------------

> Use 2x .35 gasket material and a 1mm spacer. Or only use the metal

> spacer and motoseal. Never smear that shit on paper, it just makes a

> mess when you go and take it off again and it usually doesn’t cure

> properly when applied to paper anyways.

I use Motoseal on paper all the time and no prob yet. Acetone or razor gets it off easily

Re: Eurokit hot and slow

🇮🇹💦 Of the Loin /

I like to use the big tall union nuts on heads, you get like 15-20 threads instead of like 3, so they usually don't ever back off

Re: Eurokit hot and slow

I called the air leak, no way it was running that hot well tuned without one. Now fox that shit and learn to love your eurokit 👍

Re: Eurokit hot and slow

> Mr. Duncan wrote:

> -------------------------------------------------------

> I called the air leak, no way it was running that hot well tuned without

> one. Now fox that shit and learn to love your eurokit 👍

Its always what you least expect. Looks like since I'm using the reed block to piston port adapter air was coming in via one of the intake screws and exiting via the head stud hole since they're connected. A little grey rtv on the threads should fix that up.

I've thrown it in the shed for the time being but once I get all the parts in and the motor back together I'll find this thread and update it.

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