Two things you don't need on your 2 stroke.

[upshifter]

After market parts can be good and they can be bad. I've had experience with various 2 stroke engines in motorcycles, chain saws, lawn mowers, weed whackers, model airplanes, pumps, generators, and other things, for about 50 years or more. Yes, I'm older than dirt.

FUEL FILTERS: I won't use inline fuel filters on a 2 stroke. I've seen them ruin engines. 2 Strokes use the fuel mixture to cool the engine. not just feed it. If the engineers that designed the engine would have thought in-line fuel filters were necessary they would have used them, or recommended them. They don't; because if the fuel filter becomes partially clogged, the engine will keep on running, but running hot and lean, the kiss of death for those engines. I've seen motorcycle dirt bikes seize from a partially clogged fuel filter. The in-line after market fuel filter is just one more thing in the chain that can potentially harm the engine. There is no need for an after-market in-line fuel filter.

CYLINDER LINERS: Those are not a step forward on a 2 stroke, they are a warmed over idea from the past when we still re-bored engines and installed over-size pistons. Like I've said before, BMW stopped using cylinder liners and went to chrome bores, "Nikasil", in 1981. Chrome on Aluminum is a hard surface that conducts heat away better than liners, and it saves weight. Even if the liner was a good idea, it would cost more than a new engine just to get it re-bored and fitted with a piston. I've seen new cylinders selling for about $24.00. If it fails, then slap a new piston and cylinder on it. Don't waste your money. Parts are cheap, labor is expensive.

(Also, don't believe the BS, Barbara Streisand, that you read on the internet about BMW Nikasil. I rode BMW for 15 years, about 100,000 miles, and never had a problem with Nikasil; and I never met a person who did, nor a mechanic that had seen a Nikasil failure.")

 

[srdavo]

interesting thoughts.....

about the fuel filters.....how do I keep crud out of my carb???

My Russian 2 strokes have steel sleeves & they are notorious for overheating....so that makes since!!
Are BMW's 2 stroke?????

and can we keep Barbara Streisand out of this?

 

[BSA]

After market parts can be good and they can be bad. I've had experience with various 2 stroke engines in motorcycles, chain saws, lawn mowers, weed whackers, model airplanes, pumps, generators, and other things, for about 50 years or more. Yes, I'm older than dirt.

FUEL FILTERS: I won't use inline fuel filters on a 2 stroke. I've seen them ruin engines. 2 Strokes use the fuel mixture to cool the engine. not just feed it. If the engineers that designed the engine would have thought in-line fuel filters were necessary they would have used them, or recommended them. They don't; because if the fuel filter becomes partially clogged, the engine will keep on running, but running hot and lean, the kiss of death for those engines. I've seen motorcycle dirt bikes seize from a partially clogged fuel filter. The in-line after market fuel filter is just one more thing in the chain that can potentially harm the engine. There is no need for an after-market in-line fuel filter.

CYLINDER LINERS: Those are not a step forward on a 2 stroke, they are a warmed over idea from the past when we still re-bored engines and installed over-size pistons. Like I've said before, BMW stopped using cylinder liners and went to chrome bores, "Nikasil", in 1981. Chrome on Aluminum is a hard surface that conducts heat away better than liners, and it saves weight. Even if the liner was a good idea, it would cost more than a new engine just to get it re-bored and fitted with a piston. I've seen new cylinders selling for about $24.00. If it fails, then slap a new piston and cylinder on it. Don't waste your money. Parts are cheap, labor is expensive.

(Also, don't believe the BS, Barbara Streisand, that you read on the internet about BMW Nikasil. I rode BMW for 15 years, about 100,000 miles, and never had a problem with Nikasil; and I never met a person who did, nor a mechanic that had seen a Nikasil failure.")

Yeah but chrome liners get ruined if your engine seizes up. Take your point though.

BSA

 

[Skyliner70cc]

Disgree on the fuel filter. The tanks are pretty rusty and flake off gunk all of the time. The manufacturer puts a mesh fuel filter in the petcock assembly but it clogs easily and blowing it out while on the road with fuel in the tank is something I've done and don't wish to repeat.

For my 2 strokes, the built in petcock strainer gets removed and I install a fuel filter inline. Most of HT riders are also HT builders and we have a keen ear for when our engine is running differently. A noticeably higher idle speed or snappier response or sluggishneses if you were already a little lean from fuel starvation due to a partially clogged filter would not go unnoticed by most folks.

 

[upshifter]

You won't care if there is crud in the carburetor or not if the engine seizes. Many bikes have a fuel strainer in the carburetor input line, usually at the fuel shutoff valve.

The GasBike engine kits I just bought are no exception. There is a fuel strainer mounted in the shutoff valve, that's bad enough. Why buy another one? When I put gas in a bike, I never pour the last little bit from the gas can into my bike's tank because most crud and water, if any, are at the bottom.

BMWs are 4 strokes, but the Nikasil process cylinders are the same for 2 or 4 stroke engines.

Fuel filters, cylinder liners, and other stuff make good advertising, but that's all.

Two stroke engines that run hot are usually using the wrong heat range spark plug, or running too lean. If the engine develops a small air leak, it can run lean and seize the engine.

If you're not sure that the gasoline is clean, get a funnel with a filter, or place a coffee filter in your funnel and filter it as you pour it into the tank. Also, Coleman has a small funnel with a reusable filter for their gasoline lanterns and stoves.

I never put gasoline into a bike unless I'm absolutely sure it's clean; I put the dirty gas in the lawnmower, and forget it. If it runs, I cut the grass, If it doesn't run, I go take a nap, or work on my bikes. LOL

 

[srdavo]

Disgree on the fuel filter. The tanks are pretty rusty and flake off gunk all of the time.

true statement

BMWs are 4 strokes, but the Nikasil process cylinders are the same for 2 or 4 stroke engines.

this is the 2 stroke forum & you brought it up.

I am not against learning.... but i will stick with my inline filter.

 

[upshifter]

Skyliner, I've been restoring old bikes for years. I buy a kit and coat the gas tank with plastic, and it never rusts again. Living near the beach, everything rusts quickly.

The plastic fuel tank kit will repair several small tanks. It comes with a rinse that removes any flaky rust. The next step is to put the acid "conditioner" or "Etcher" in the tank and all the rust wil be neutralized. Then rinse the tank and dry it. After that, put the liquid plastic in the tank and move the tank around so the plastic coats everything. Then you let the tank dry for a day or so. Once it's coated it is fixed for good.

I haven't had any need for a fuel filter other than the one in the carburetor or the fuel valve.

But, they sell plenty of them, so they can't be all bad. But, I won't use them.

 

[srdavo]

Skyliner, I've been restoring old bikes for years. I buy a kit and coat the gas tank with plastic, and it never rusts again. Living near the beach, everything rusts quickly.

The plastic fuel tank kit will repair several small tanks. It comes with a rinse that removes any flaky rust. The next step is to put the acid "conditioner" or "Etcher" in the tank and all the rust wil be neutralized. Then rinse the tank and dry it. After that, put the liquid plastic in the tank and move the tank around so the plastic coats everything. Then you let the tank dry for a day or so. Once it's coated it is fixed for good.

I haven't had any need for a fuel filter other than the one in the carburetor or the fuel valve.

But, they sell plenty of them, so they can't be all bad. But, I won't use them.

I appreciate the info. the older Grubee 2 stroke kits, came with a standard, lined fuel tank. The newer kits (non-grubee) I have seen are cruddy.

A lot of us here, Skyliner70cc included, have been building these bikes for several years. We have some credentials , too.
No one has reported any problems with an inline filter.

 

[graucho]

I also have been using inlines for years. I do like threads that make me scratch my head
for a few minutes. If your statement is true, maybe ive been lucky since I buy a ten
pack on ebay and change them early spring and mid summer. I also try to buy them clear
if they have them in stock so I can keep an eye on things.

 

[spad4me]

I buy the biggest clear inline filter I can find in a year I have gone through 4.
The old fuel tanks in the local gas stations are contaminated with water, dust, urine and rust.
I have replaced a fuel regulator on my sons truck $96.00,
a fuel pump in my van $396.00. Because of the seasonal monsoon flooding the gas station fuel tanks.
a new fuel filter is cheap insurance.