HF engine tips and tricks

[Dan]

Really enjoying my HFs and wanted to start an informational thread on em. Please feel free to add any thing you'd like.

Spark plug replacement; NGK would be BKUR6ET and champion would be; KY7YKJCR. HF manual says gap is 0.027” to 0.031

(sources; Nanjing Huade Spark Plug Co.,(NHSP) and http://manuals.harborfreight.com/man...7999/97964.pdf )

I had forgotten to check the plug gap. The engine ran fine but when Elmo and I spoke about replacement plugs, I got around to it and made a world of difference. Now idles much lower and smoother. A really surprising thing is I had beaten the poor clutch to death so it stuttered at dead stops to 4 or 5 MPH. Gaped the plug and now is 1,000% smoother on take offs. I wouldn't have thought of that in a million yrs. Always some thing to learn I guess.

Air intake;
Test ridding a prototype at the end of this winter. I noticed my Carhartts would partially cover air inlet. Eventually removed cover all together as the engine governor arm is removed and runs at 5,000+ RPM and needs more air. I hold the filter and plate in with a chicken wire cover. (Pic below) TS is laughing at me. I plan on replacing it with some thing prettier for a show bike. (This is a test bike)

Fuel;
Manual states 89 octane or above. First few hundred miles. I ran 93 then switched to 89 and noticed no difference. Ethanol is reported to be ruff on any small engine and there are gas stations that sell fuel w/out it. None near me of course but hey. ethanol free gas stations - Google Search.

The low oil censor is easily disconnected. it just unplugs at front of engine, half way up the wire. Really simple)

The engine loves a st8 exhaust pipe and has great rumbling sound. Really old school MB thump-thump. I added a 8HP lawn mower muffler from ace hardware for the neighbors. Lost about 4 or 5 MPH. Cost about 8 bucks and change. But can be greatly improved and will be some day, snork. The 2do list grows by the day.

Cooling shroud;
The small pc that guides air from left to rt on top of the cooling fins. As an experiment, I ran with it for around 800 miles. The engine stayed so cool that you could comfortably touch the manifold after shutting down for 4 or 5 mins and touch most of the pipe during an hr long ride. But the engine gets more RPM and runs better hot. I took it off and have just a tad more umph. I live in CT so folks in warmer climates might want to experiment. One bolt holds it on and in place so not a biggie.



Pics; 1, Muffler. 2 Chicken wire air filter cover. 3, new kickstand from Spookytooth. 4&5 dash board. (Unfinished. GPS is attached with velcro and stays on even bouncing over rail road tracks at 35 MPH. It was rusticoRay's idea and works great!)

 

[Gator Wrestler]

I have been riding my HF build for about a year now and it's my favorite bike. I removed half of the fan blades that drive the air flow to cool the engine. Remove every other one like the cart guys do and notice an increase in power. I didn't remove the gov. just disconnected it. Along with a free flow exhaust this thing hauls a$$.

 

[Dan]

Wow Gator, I would not have thought of that. Gonna try it today or tomorrow. It is especially good to hear given where you live. I was worried about the cooling thing just removing the shroud.

I also just removed the arm for the gov but am gonna try the internals.

Thanks for the post. Makes big time sense. Spinning mass an' all.

 

[tyrslider]

Dan,

Great thread! Love the dash, you need an oil press gage, anglometer, altimeter and compass w/ all that room! The chix wire isn't that bad (not what I'd invisioned, much tidier).

Gator,

Been looking into a new starter set up and removing the fan all together (for width and power), but it didn't occur to me to remove 1/2 the blades! Good thinkin' thanks for sharin'

 

[Dan]

Dan,

Great thread! Love the dash, you need an oil press gage, anglometer, altimeter and compass w/ all that room! The chix wire isn't that bad (not what I'd invisioned, much tidier).

Gator,

Been looking into a new starter set up and removing the fan all together (for width and power), but it didn't occur to me to remove 1/2 the blades! Good thinkin' thanks for sharin'

LOL, love the altimeter idea! dat2funny. ..an' going on the flying MB. Hadn't thought of oil pressure! Thats a great idea and am gonna find a cool old one. (read ask Tom where to find a cool one. The GPS actually has a compass and comes in handy.

We really need to come up with gen capability.Working on the solar thing first here though.

When I told ya about the wire cover, the pregnant silence was 2 funny but could hear your thoughts. "Oh Lord......" LOL

 

[MaxPower]

I had a problem with the first HF engine I bought. It would not idle. I took it back to harbor freight and since it was within the manufacturer warranty, they gave me a new one. They were really cool about it. the engine was in pieces when I returned it too them. I went mid-evil on that engine trying to get it to idle. If you have problems out of the box then it's probably a quality control issue. they are cheap engines.

 

[Elmo]

Dan thanks for alerting me to this thread, I missed it somehow. I like the chickenwire aircleaner, We call it hardware cloth down here. Gonna rig one up tomorrow. The dashboard is way cool.

 

[tyrslider]

Heres another tip. If you lube the tangs on the pull starter they're less likely to dislodge. This can happen if your having starting problems and pull on the starter a bunch of x's in a row causing it to stick and requiring disassembly.

 

[Dan]

LOL w/ "hardware cloth"

"Timy Nase here. New from dansco, Hardware cloth air filter! Keeps air filters on and palmeto bugs out. Order today and receive an extra hardware cloth cover ansolutly free! A 4 cent value as our gift free gift to you."

Dash Board sound video by dan3xd - Photobucket

 

[silverbear]

Great thread here, which I'll be following closely. I think I can see off in the distance a HF engine in my future. Their price is sure right.
SB

 

[silverbear]

Yes, I never could figure why it was called "hardware cloth", but chicken wire is a different thing altogether. You can get it in different sized mesh. Maybe paint it the same color as the bike frame to make it look more like 'it's sposed ta be like that'. A shiny trim piece around the edge would dress it up, like for kitchen counters and that sort of thing. Or aluminum plate with a bazillion holes drilled it it. Or something else which has not yet occurred to me. Brass screen would be nice. No way to tap in to wire LED lights eh? Why not? It wouldn't take much juice for LEDs.
SB

 

[Dan]

TS, Gonna do the "Gator Fan method" (thanks again Gator!) so will open it up and grease it as well an' report (Think I might have a way to do an elec start) ((

Just looked SB, 88 bucks! hehe and I am searching for their 10% off coupon. Really is a great lil engine.

 

[RusticoRay]

Tip # 1 take it out of the box and beat the living piss out of it if it fails your out 74.00. Mine by the way has about 600miles of extreme abuse.

 

[Dan]

Tip # 1 take it out of the box and beat the living piss out of it if it fails your out 74.00. Mine by the way has about 600miles of extreme abuse.

LOL, about what I did. Picking up another Wed. Might try being nice to the poor thing.

prolly not.

Was gonna send you a link to this thread and wanted to ask what your getting for rpm?
Also invite you to the HF/4 smoke contest. (no rules, just rite, lol)


http://motorbicycling.com/f37/hf-contest-any-bike-4-stroke-18912.html

 

[Dan]

Yes, I never could figure why it was called "hardware cloth", but chicken wire is a different thing altogether. You can get it in different sized mesh. Maybe paint it the same color as the bike frame to make it look more like 'it's sposed ta be like that'. A shiny trim piece around the edge would dress it up, like for kitchen counters and that sort of thing. Or aluminum plate with a bazillion holes drilled it it. Or something else which has not yet occurred to me. Brass screen would be nice. No way to tap in to wire LED lights eh? Why not? It wouldn't take much juice for LEDs.
SB

I missed that post. Some great ideas SB. I was also thinking the sort of fancy chrome heat shield stuff. Dunno. Forgive the city boy question, but what kinda wire do I have? lol (gotta be a Yankee joke in there but I don't wanna get you guys going)

Elmo found some more plugs; " I haven't found any local yet but I did find a few more numbers. NGK-BP6HS, CHAMPION-L92YC, AC-43F8, AUTOLITE-274, BOSCH-W6BC & WR6BC+. These numbers came from a crossreference web site."

 

[Elmo]

I went to the outdoor power store yesterday and bought a NGK-BPR4HS plug and it works at least as good as the chinese one. Tha guy said that is the one they use for chinese honda clone engines. It appears to be a hotter plug, the electrode is extended farther than the chinese one. The 4 is the heat range and I bet the R means resister. Most likely a hotter resister version of the NGK-BP6HS.

 

[corgi1]

Dan,,,I was looking at dash board sound vidio and saw a wizzer and ht togeather,the wizzer has a larger tank ,is that a 4 liter(I think)as in we can get larger gas tanks?(on the wizzer)

 

[Dan]

Sorry to report no whizzer or 4LT tanks Corgi. Just really, really bad vid, lol

Dash Board sound video by dan3xd - Photobucket

 

[corgi1]

It came up different the first time w/a lot of small still pics

 

[Dan]

oh! and it looks like a bicycle recycling plant was fire bombed in my garage

I was sort of hoping Carol got me a whizzer as a surprise.