HF 2.5HP - hard starting?

GoldenMotor.com
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kallsop

Member
May 2, 2009
106
1
18
CT US
I'm almost ready to start my HF + CVT build. I bought a HarborFreight 2.5HP 80cc engine back in December and it's been sitting in the box until now. The engine most of the time won't fire up. There is a spark, the air intake is unobstructed, the fuel supply appears to be good, the choke lever works. I pulled the rope so many times I broke and mechanism and had to take it apart. One of the pop out wing things had come out of it's groove. It's all back together now, no harm done and I am more careful to not jerk the rope at the end of the pull.

When the engine does fire, it seems to be random because it will fire and run strong as if it had started on the first pull and not the 150th pull. There is the right amount of oil in the sump and I tried disconnecting the oil sensor wire, made no difference. I ran a full tank of gas last time the engine started, no problem once running at all. It runs strong.

Any ideas what could be making this engine a tough starter?
 
tyrslider

tyrslider

New Member
Sep 26, 2008
958
2
0
RainCity
There is confusion on oil level, go by the capacity (oz/cc) and do not screw the dipstick in to check oil level. W/ engine level it should, essentially, be impossibe to over fill. There is also two level indicators inside the filler hole. When full it is almost right up to the bottom of the filler opening. The Oil level sensors can be kinda touchy and if being so could certainly cause intermittant running.

Bypass the on off switch (that'll also take the oil sensor out ' the equasion) i.e. remove it. If that solves your problem, you can use your choke to kill it when it's warm.

I have noticed that the starter is weak (doesn't break but comes apart on occasion).

Hope this helps! Cheers, Evan.
 
Dan

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Howdy Kallsop. Found the same thing the first couple of weeks with the HF. Just my method but works for me. I pull the line slowly out as far as if pulling fast to start, just to roll it over. Then allow line to fully retract. Pull slowly until I feel it catch then pull hard. (not in a jerking fasion) Starts in 1 to 3 pulls. OH, I start with half choke. The engine is fairly new and we are just learning each other. Some times She would light right off and others, it was WTH an' take a break. LOL

Noticed your from CT. We're having a MB get together May 2nd in Wethersfield. http://motorbicycling.com/f35/there-going-east-coast-mber-rally-16556.html

Cook-out and a ride thing. Some really great folks and builds. Hope ya can make it.
 
R

RusticoRay

New Member
Oct 3, 2009
170
0
0
6mi. from the Old North Bridge
Hi Kallsop, Did you strip the govenor off the motor? I know on both motors I have I needed to crank up the idle or it was hard to start. The oil level I just fill it on level ground until it comes out of fill plug hole. Also you have to remember the quality control on a 71.00 motor is what you pay for.
On my new HF I have had to tighen the float bowl, fuel all over the garage floor in the morning and last nite it just wouldn't run at 1/2 to full throttle had to drive 5 miles at 5 mph home( could have had to walk it so not so bad ). The jet had a big peice of crud in it. Good luck and I too hope to see you on May 2
 
professor

professor

New Member
Oct 14, 2009
500
1
0
Buffalo ny area
Here is what I noticed- the fuel in the carb evaporates (giving off gas smell) and when I turn on the gas valve, it takes a little time to get the gas into the carb. Other than that, the main jet is lean, so the choke needs to be kept on for longer than normal.
 
K

kallsop

Member
May 2, 2009
106
1
18
CT US
Thanks for all the advice. The engine still has the governor and stock throttle linkage. It doesn't appear to leak gas and there's no gas smell or stain on the floor. I doubt this bike will be ready by May 2nd and besides, that's my birthday and the family will have different plans.
 
Elmo

Elmo

New Member
Sep 3, 2009
748
4
0
Mississippi
Mine usually cranks on the second or third pull, full choke. Like the Professor i had to idle it up a little. Governor disconnected from carb with a brake lever throttle. Still slow enough that the centrifugal clutch does not engage. Haven't had any trouble with the pull start on this one, the first one cranked with the rope at full extension and ate the mechanism, HF gave me a new engine no questions asked. I really like mine very reliable so far, 425 miles on it good mileage too 150 to 160 mpg geared at 12 to 1.
 
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Dan

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Elmo, tried your advice and been starting full choke. Works great! Thanks! Dunno why I was being timid about choking. Although the judge.... never mind

Works great, again TY
 
Elmo

Elmo

New Member
Sep 3, 2009
748
4
0
Mississippi
tyrslider said:
150 mpg! Wow!
Click to expand...
I rode it on one of my old pedal rides up the Natchez Trace which is a measured 50 mile ride. The trace is a somewhat limited access road with a 50 mph speed limit with no stop signs or lights so I was able to ride without many stops. I went 23 to 25 mph which according to the gear calc 3600 to 3800 rpm. It took 36 0z to refill.
 
Dan

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Very cool Elmo

Every time you mention Natchez, it brings back some really great memory's. I might have to take a week off and go back down. Carol loves road trips.
 
Quenton Guenther

Quenton Guenther

Dealer
Feb 21, 2008
686
1
0
Outer Banks of North Carolina
Hi Kallsop,

Be sure to remove the right side cover and look at the magneto. One of the issues with the HF 79 CC motor is they aren't consistant, some run good, some run fair, and some run poor.
On 2 of the HF motors the magneto was badly bent and was very intermitten, the first magneto issue was discovered at Lewes, DE last year, and a few weeks ago another magneto problem was discovered on a build in OH. The magneto should be straight [not bent], and should be approx .010" from the flywheel. After viewing the defective magneto it is hard to believe it passed quality control, because they both looked like a truck ran over them, and was hard to beleive they ever worked at all [they did, but very intermitten]
Another problem with the HF motors has been the low oil shutoff circuit, if it is like the Honda disconecting the defective sensor will eliminate the issues. The Honda oil sensor shorts part of the coil to ground, and I would think the HF has a similar system.

Have fun,
 
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