Cylinder Wall

proneto911 · Feb 24, 2015

Wondering if this is normal wear? this is the only thing i'm worried about. it runs very well and at stock got it about 30mph or a little more will have to use my gps and clock myself when it gets warmer in Chicago area. dont really go over 20mph gets a little too much vibration and don't want to go overboard.

Went through about 2 tanks of gas. The first i had it at 32:1, second tank went up to 40:1, the current i have is 50:1 before winter really hit. Ran super and probably not going any higher. Might put in a cup or two of 75:1 at some point and see how well it runs but will probably stay at 50:1.

http://1drv.ms/1Dnqo9W
5 total pictures.

I do have a feeling i'm going to need a few parts. like the cylinder itself because it just doesn't look right to me for some reason. if its not ill take it off and look at the rings as well see if i need to replace them.

Spark plug is chocolate color looking so its the right temp from reading around in the forum. The plug is an NGK B-4L going to change to BL7H? cant remember have it in my notes on my phone. Unless anyone has a better suggestion.

mapbike · Feb 25, 2015

well you do have some s retches in the jug, hard to tell if they're deep enough to cause much trouble, but the piston looks clean.

One thing that comes to mind is to ask what kind of air filter are you using?

spark plug you should be using would be a B6HS NGK plug or if you want a cooler running plug you could use the B7HS NGK.

If you do decide to replace the Cylinder and rings, you will need to look at the connecting rod and look to see what it says on the side of it, you'll be able to find out what engine geometry you have that way.

if the rod says FM80 or ZAF80 on it you'll know you need a GT5/Skyhawk type cylinder because you engine is a 38mm stroke with a 114mm length rod.

If the rod says ZAE50 you have what we call a Half Breed engine and the uses the same cylinder as a 40mm stroke engine.

If the rod has no marking or the Z-L marking you have a 40mm stroke PK80 type engine which is the easiest to find the cylinder.

either is available from forum vendors or from ebay vendors.

proneto911 · Feb 25, 2015

i'm using the original NT carb filter. i would like to change it out but i like the idea of the air inlets being down so no water gets inside. if there is something similar i'm all for it. i dont like the mesh thats in there right now just haven't found a replacement yet for it that lets a lot of air through.

I will go to my local auto parts store and get a few B6HS plugs tomorrow and install one. shouldn't be that much lol

mapbike · Feb 25, 2015

proneto911 said:
i'm using the original NT carb filter. i would like to change it out but i like the idea of the air inlets being down so no water gets inside. if there is something similar i'm all for it. i dont like the mesh thats in there right now just haven't found a replacement yet for it that lets a lot of air through.

I will go to my local auto parts store and get a few B6HS plugs tomorrow and install one. shouldn't be that much lol

I like the stock type filters ok also for the same reason you said, one thing I do to mine though is I spray them with foam filter oil, its a very sticky stuff once it sets and it prevents dust and dirt from being pulled through filter but also breathes good.

Most any motorcycle shop will have it in one brand or another here is what I'm talking about.
http://www.atvparthub.com/99200_A400W_93910_A13_5_BelRay_Foam_Filter_Oil_Spray?src=BingS

cannonball2 · Feb 25, 2015

Yeah that certainly does look like particle ingestion. Do like Map says. For any of you guys that have a jug that is so perfectively ported/timed that you never want to see it go away, you can have it hard chromed plated for a mere $199 at US Chrome.

You send them the jug and piston you are going to run, they plate the jug and hone it to fit the piston. You can then run rings with more tension and tighter gaps for more power. This is a thick plating unlike the THIN Chinese stuff.

Davezilla · Feb 25, 2015

I'll agree, it does look pretty scratched up from particle ingestion... same for the air filter, if you want to keep the stock filter it'll do but spray it down with some filter oil like the stuff Map posted or K&N filter oil. It's sticky so the dust clings to it instead of going down the carb and into your engine, Also since these are 2 smokers, anything that can scratch up your cylinder walls can also do a number on your rod and crank bearings.
I saw somewhere where someone was in a really dusty environment where these filters didn't do much good so he made an adapter so he could run a Tecumseh air filter with a paper element, but you can also use an oiled foam element inside a Tecumseh filter housing so you got a less restrictive filter inside a housing that can keep water splashes out, and if an oiled foam element is used instead of the paper element you can clean and reuse it numerous times, the paper elements filter out tiny dust particles very well but can clog up quickly in a really dusty environment so I'd go with oiled foam if this is the case.

mapbike · Feb 25, 2015

Davezilla said:
I'll agree, it does look pretty scratched up from particle ingestion... same for the air filter, if you want to keep the stock filter it'll do but spray it down with some filter oil like the stuff Map posted or K&N filter oil. It's sticky so the dust clings to it instead of going down the carb and into your engine, Also since these are 2 smokers, anything that can scratch up your cylinder walls can also do a number on your rod and crank bearings.
I saw somewhere where someone was in a really dusty environment where these filters didn't do much good so he made an adapter so he could run a Tecumseh air filter with a paper element, but you can also use an oiled foam element inside a Tecumseh filter housing so you got a less restrictive filter inside a housing that can keep water splashes out, and if an oiled foam element is used instead of the paper element you can clean and reuse it numerous times, the paper elements filter out tiny dust particles very well but can clog up quickly in a really dusty environment so I'd go with oiled foam if this is the case.

oiled foam is great, K&N oil is ok but not actually intended for foam filters, the real tacky stuff specifically for foam filters is best, the reason I say this is because I have Nitro Powered RC trucks and a 4x4 buggy, they all use foam filter eliments and they get totally covered in dirty and fine dust, people have ruined there engines quickly by using K&N filter oil on the RC foam filters ecause elieve it or not dirt will get through it, K&N oil is made thinner and less tacky because its actually for cloth filters, foam filter treatment dries thicker and much stickier than K&N oil.

I use the K&N oil on all my RT carb cloth filter but I use the good foam filter oil on the foam filters because it let virtually no anythi g but air get through.

Just a tid bit I thought Id add, no shooti g you down in any way brother Dave.

Davezilla · Feb 28, 2015

No worries... it's very well known that dirt track racers don't use K&N filters because the smaller dust particles do make it thru and they eat up engines a lot faster. K&N filters are great for the street, but not for really dusty environments or any type of dirt track racing.

If the foam filter oil is really tacky and sticky that would be the stuff to use in a dusty environment. It may be too sticky to use on a cotton type filter but in foam that's what it's made for.

On my sportster I got one of those large cone type filters but it was too restrictive so I burned the cotton out of the element and oil the screen mesh, but I also don't ride that one in dusty conditions at all because of that. I do have an Outerwears filter cover that I use when it rains or if it's a really dusty day since it flows really well but repels water like crazy and it also keeps any fine dust from getting in.

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Cylinder Wall

proneto911

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mapbike

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proneto911

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mapbike

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cannonball2

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Davezilla

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mapbike

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Davezilla

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