Semi-abandoned Hammerhead 250

[madprofessor]

I should’ve asked this before, but I’m using regular 87 octane to try and get it running. Should I be using something higher? I was hoping to run it on the no-ethanol stuff QT has when it’s actually running so it doesn’t destroy the carb seals or gunk it up as bad if it has to sit at some point, but regular 87 is what I had in a jug when the starter fluid ran out. The 87 is fresh, I filled the jug up for a neighbor a few days before I started messing with the kart.

Huh, so that's how I address a particular comment, the reply button. So Ken, about the ethanol thing, I want to know some stuff............
Firstly, the octane though.......... Never heard a small engine mfr. recommend octane rating higher than 87, and my best understanding of the rating is simply that the higher the rating, the higher the temperature at which the fuel will spontaneously combust. So a high compression engine that makes the air/fuel mixture hotter via more compression might have the mixture detonate before the plug fires if octane rating is too low.
Now the ethanol........... I know nothing about it. Predators have a sticker on the gas tank about ethanol, and I seem to recall it said "No E-85 ethanol", might have that wrong, no matter. I want to know what ethanol vs. gasoline does and doesn't do, what the advantages/disadvantages are, performance/longevity overall, etc. Anybody out there have answers for Ken and for myself?
Bonus: Any info on kart racer's methanol would be of interest, and any would be more info than I presently have.

 

[KenMathisHD]

Huh, so that's how I address a particular comment, the reply button. So Ken, about the ethanol thing, I want to know some stuff............
Firstly, the octane though.......... Never heard a small engine mfr. recommend octane rating higher than 87, and my best understanding of the rating is simply that the higher the rating, the higher the temperature at which the fuel will spontaneously combust. So a high compression engine that makes the air/fuel mixture hotter via more compression might have the mixture detonate before the plug fires if octane rating is too low.
Now the ethanol........... I know nothing about it. Predators have a sticker on the gas tank about ethanol, and I seem to recall it said "No E-85 ethanol", might have that wrong, no matter. I want to know what ethanol vs. gasoline does and doesn't do, what the advantages/disadvantages are, performance/longevity overall, etc. Anybody out there have answers for Ken and for myself?
Bonus: Any info on kart racer's methanol would be of interest, and any would be more info than I presently have.

I may be wrong on this, but my understanding is that regular gasoline has something like 10%-15% ethanol content. The ethanol in that fuel generally isn’t an issue for modern fuel injected vehicles that are designed with that in mind, but for older vehicles or our smaller engine vehicles/appliances/tools where they tend to not be designed for that or are not used frequently and sit for extended periods of time, it can be an issue.

Ethanol is alcohol based, as as our tools, karts, appliances sit in storage between seasons or what have you, it can start to eat away at the seals and cause fuel leaks. Even if used frequently, the ethanol can still eat away at the rubber seals we use, albeit not as quickly. I believe it is also slightly hydrophilic - it attracts water - which can cause internal parts to rust.

The Pros and Cons of Non-Ethanol Gas - Salem & Portland, Oregon

Do you know the downsides and upsides of non-ethanol gas? Let MNOP teach you about non-ethanol gas benefits and when this type of gas is best used.

marcnelsonoil.com

There’s an article above that I was reading - apparently ethanol gas is prone to oxidizing quicker than non-ethanol gas, so the non-ethanol fuel should have a longer shelf life. One thing I’m not sure about is they claim ethanol based fuels have higher vapor pressure than non-ethanol based fuels, which can lead to vapor lock.

Here’s a couple more links to things that talk about the differences

The Major Differences Between Ethanol and Gasoline

This article explains the major differences between ethanol and gasoline.

www.google.com

Learn & Discover

Find inspiration, how-to's, buying guides, offers and more.

www.husqvarna.com

What fuel is best for small engines? | Briggs & Stratton

Need lawn mower gas? Find small engine fuel type and storage recommendations for max performance from the Briggs & Stratton Engines experts.

www.briggsandstratton.com

How to Fight Ethanol Problems in Small Engines - AMSOIL Blog

Small-engine manufacturers warn that ethanol can dissolve plastic and create harmful deposits, leading to costly repairs. Here's what you can do about it.

www.google.com

Ethanol Gasoline Blends and Small Engines - Oklahoma State University

A guide to help consumers decide if using ethanol blended fuels is appropriate for them.

extension.okstate.edu

 

[madprofessor]

You're well-versed on the ethanol, Ken, research pays off. Just read all of those links, answered all my ethanol questions.
My conclusions about the ethanol lead me to change one thing about my own karts and other small engines. Considering the small amount of fuel they use, and the long periods of only infrequent use, I'm going to find a local gas station with ethanol-free pure gas and buy a can-full of the highest octane rated of same.
The added cost will be insignificantly minimal for my level of use, and the advantages could be great. The surely definite advantage for me will be something that I need, less confusion about fuel I have and/or am using, and no stress in the back of my mind about there possibly being some fuel-related wrong that I'm unaware of.

 

[Denny]

87 octane is fine unless you have engine ping. Higher octane will not make more power. Alcohol is bad with all metals and rubber parts.

 

[KenMathisHD]

I

You're well-versed on the ethanol, Ken, research pays off. Just read all of those links, answered all my ethanol questions.
My conclusions about the ethanol lead me to change one thing about my own karts and other small engines. Considering the small amount of fuel they use, and the long periods of only infrequent use, I'm going to find a local gas station with ethanol-free pure gas and buy a can-full of the highest octane rated of same.
The added cost will be insignificantly minimal for my level of use, and the advantages could be great. The surely definite advantage for me will be something that I need, less confusion about fuel I have and/or am using, and no stress in the back of my mind about there possibly being some fuel-related wrong that I'm unaware of.

I believe most QT stations have the non-ethanol fuel, I know the QT by our neighborhood entrance does. I think it’s their red-handled pumps?

You can use to pure-gas.org to find ethanol-free stations in your state, it brings up a map with all the stations that sell an ethanol-free fuel.

 

[KenMathisHD]

So I got it running with the new carb, and it fires up on the first try now. Doesn’t sound super healthy though, sounds like something may knocking internally. Never had one of these before so I was hoping one of y’all could take a listen and see what you think. Link to the video is below

 

[KenMathisHD]

Second video for it

Hammerhead 250 GoKart possible motor knock

Picked up this abandoned go kart at a storage unit for cheap and just got it running, but it doesn’t sound super healthy.

youtube.com

 

[Denny]

To me it sounds like an exhaust leak. In reality I can’t tell.

 

[madprofessor]

Go to walmart.com and search "mechanic stethoscope". Order yourself a $11-$13 scope, you'll use it the rest of your life. Just be sure it has the extra long (22.5cm or similar) probe with it. Don't screw the probes in too tight, they're easy to strip out. Don't ram a probe tip straight on into any iron with scope in your ears, you'll be deaf for the next hour. Incredible how that thin little metal disc in there amplifies sound.
Keep pressing the tip straight on into various spots all around the engine. You'll very quickly learn what a crankshaft bearing and rod bearing sounds like rotating, a piston sliding in the combustion chamber, valves tapping up/down, much more.
If there's a rod tapping, you'll here it through the crankcase. Valve tapping: valve cover. And etc.
Agreeing with Denny about exhaust leak. Second video has it missing a beat here and there, like exhaust. A tapping rod's consistent, as are most worn parts in an engine.

 

[KenMathisHD]

Go to walmart.com and search "mechanic stethoscope". Order yourself a $11-$13 scope, you'll use it the rest of your life. Just be sure it has the extra long (22.5cm or similar) probe with it. Don't screw the probes in too tight, they're easy to strip out. Don't ram a probe tip straight on into any iron with scope in your ears, you'll be deaf for the next hour. Incredible how that thin little metal disc in there amplifies sound.
Keep pressing the tip straight on into various spots all around the engine. You'll very quickly learn what a crankshaft bearing and rod bearing sounds like rotating, a piston sliding in the combustion chamber, valves tapping up/down, much more.
If there's a rod tapping, you'll here it through the crankcase. Valve tapping: valve cover. And etc.
Agreeing with Denny about exhaust leak. Second video has it missing a beat here and there, like exhaust. A tapping rod's consistent, as are most worn parts in an engine.

The exhaust is on the opposite side from where I’m hearing the noise though. It sounds a lot like metal hitting metal, a hollow sort of clonk sound. I’ll order that mechanical stethoscope - tried using a long screwdriver but no dice. Really hoping it’s not a rod bearing or something like that. I took some pictures of the oil after changing it - it looks kind of shiny like it has some metal material in it. Is that normal for small engines, or maybe I’m just seeing stuff? The one in the cap is after the first change, the one in the drain pan is after the second.

Also, I’m still not quite sure why it’s missing every now and then while idling - maybe a vacuum leak somewhere? Is it possible for the timing to be off on these? I didn’t see a way to adjust it, but when I give it a little throttle from idle it vibrates pretty bad, shakes the whole rear of the kart. It smoothed out a little bit afterwards, but then shakes more at higher throttle. How’s the timing controlled on these?

 

[madprofessor]

All metal, powdered or chunks, will be in the bottom of any oil. Nothing mixed in suspension.
If you can determine what thread size is on your drain plug, like 1.25"-12tpi, summitracing.com has a huge inventory of magnetic drain plugs at very reasonable prices (before shipping) that can usually tell you a lot about your engine's condition.
Amazon sells a "Prima" plug for GY6 engines, but all the reviews say it didn't fit, or the magnet shattered. Triple A: Avoid Amazon Anxiety.

 

[madprofessor]

I just watched a youtube video called "twister hammerhead 250 teardown", a search for "twister ham" will pull it, just scroll down to it.
No real answers for you in it, but will get you more familiar with what you're seeing of your engine.

 

[KenMathisHD]

All metal, powdered or chunks, will be in the bottom of any oil. Nothing mixed in suspension.
If you can determine what thread size is on your drain plug, like 1.25"-12tpi, summitracing.com has a huge inventory of magnetic drain plugs at very reasonable prices (before shipping) that can usually tell you a lot about your engine's condition.
Amazon sells a "Prima" plug for GY6 engines, but all the reviews say it didn't fit, or the magnet shattered. Triple A: Avoid Amazon Anxiety.

Gotcha ok. Any idea on what I’m seeing in the oil then? I don’t usually see that in the oil I drain from my other vehicles but maybe that’s just a small motor thing?

I’m gonna pull the belt and variable clutch off and see if I can isolate the noise as coming from the motor. I know the clutch is toast, some I’m wondering if it’s what’s clunking around, or if something in the CVT is making the noise. Still need to order the stethoscope. I don’t think it’s an exhaust leak since what I’m hearing is coming from the left side of the motor, gets quieter going up towards the exhaust. I should probably see about taking off all the air box crap on it since it’s not hooked up, get it out of the way.

 

[KenMathisHD]

I just watched a youtube video called "twister hammerhead 250 teardown", a search for "twister ham" will pull it, just scroll down to it.
No real answers for you in it, but will get you more familiar with what you're seeing of your engine.

Is it the one by Mackey’s Motors Inc?

 

[KenMathisHD]

Yea.... it was the clutch alright

 

[KenMathisHD]

 

[Denny]

Seems like a lot of shiny stuff in the oil. Hard to tell on screen though. JMO. Kudos on finding the broken parts in the clutch.

 

[madprofessor]

Yes, Mackey Motors is the video. Saw stuff I've never heard of on that. The external valve adjusters are just crazy! Learned some stuff.
and.............Wow! That clutch is mangled up worse than my second wife's sanity. Hope it's an easy one for you to locate new.

 

[KenMathisHD]

Yes, Mackey Motors is the video. Saw stuff I've never heard of on that. The external valve adjusters are just crazy! Learned some stuff.
and.............Wow! That clutch is mangled up worse than my second wife's sanity. Hope it's an easy one for you to locate new.

They’re out there new, but at $200-$300 a piece, I think I’ll wait on it for a little while and get the rest of the thing done up ok. No point buying a clutch until I have wheels and tires for it to drive on.

Also, what do y’all recommend using for battery terminals for this thing? Now that it runs ok and I’m getting into wiring, I want a good, solid connection on this so my power flow is consistent. I was thinking of using some steel bolts and washers to press the wires against the terminals, but didn’t know if there was a better option out there.

Current setup is kind of janky

 

[Denny]

I would go to NAPA and see if they have some type of ends before I did that. Use stainless steel hardware it will not rust.