I just finished building my first motorized bicycle. It is a GXH50 on a friction drive. I have warmed up my Honda GXH50 twice now. It has not been ridden because I am recovering from being ill. The second time (today) I noticed that there is quite a bit of blue smoke coming from the engine. This seems strange because it has not been under any load as of yet. I have the fuel tank close to carburetor level and the fuel pump is not working well enough to keep the engine running without jacking up the front tire 10”. I am worried that it may have run lean during the warm-ups. But I do not think this would be a problem in the short warm-ups I have done. I did not notice any overheating. I have owned many Hondas in my life and have never had one that smoked when it was new. Is it normal for a new, un broken in GXH50 to smoke? Also, this pump looks just like the GXH50 pump but it is not a Honda part. Is the engine too small to run this crank vent fuel pump? I have tried it with the vent directly into the pump, no exterior vent other than the pump vent. Completely open T connection. And several degrees of resistance. with the same results.
Blue smoke from a new Honda GXH50?
- Thread starter DragonSlayer
- Start date
You need to stop doing the warmups and actualy put a load on the engine! A new engine, purposly, has a sorta rough crosshatch hone on the cylinder bore to make the rings wear slightly and conform to the bore and obtain a good seal.
By starting and running the engine without a load, the crosshatch will smooth out, and the rings will never have the optimum seal, and the engine will suffer in performance and longivity.
Synthetic oil during break-in has also been proven detrimental to getting good ring seal.
I'm not sure about your pump/ vent problem, but 4 strokes are rather resistant to damage from running lean for short durations, especialy only warmups.
I would suggest not running it anymore unless I was gonna drive it. If it don't seem to run good, try adding some choke control and see what it does, and diagnose from there.
By starting and running the engine without a load, the crosshatch will smooth out, and the rings will never have the optimum seal, and the engine will suffer in performance and longivity.
Synthetic oil during break-in has also been proven detrimental to getting good ring seal.
I'm not sure about your pump/ vent problem, but 4 strokes are rather resistant to damage from running lean for short durations, especialy only warmups.
I would suggest not running it anymore unless I was gonna drive it. If it don't seem to run good, try adding some choke control and see what it does, and diagnose from there.
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A load on a motor takes the chatter out of new piston rings. It holds them still and lets them train/wear mate to the cylinder nicely. No load and simply idling or reeving a new motor will let chattering occur and the wear mating surfaces will be compromised a bit. After the rings have broke in and seated to the cylinder. ''wear mated'' this is not a problem.
Just that this is a pretty much universally accepted form of new motor break in. I concur and thought to add to WayneZ's reply.
Just that this is a pretty much universally accepted form of new motor break in. I concur and thought to add to WayneZ's reply.
when i did rebuilds in engines where i used to work,i would warm it up,check the levels and drive it.the intrepid 3.3's had a piston slap issue,and had to replace pistons/rings under warranty,i'd take them for a drive-straight out onto the highway.
any small block chevy i did - same thing,except i'd drive it kinda hard out the door.
they all held up good.
to idle a new four stroke for any extended period will slow the break in procedure.
camshafts need rpms to seat properly too.
work it,but not wide open for extended periods.
any small block chevy i did - same thing,except i'd drive it kinda hard out the door.
they all held up good.
to idle a new four stroke for any extended period will slow the break in procedure.
camshafts need rpms to seat properly too.
work it,but not wide open for extended periods.
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blue smoke indicates oil burning. make sure you dont have to much oil. probably just need to ride it a time or two,to get the rings to seat properly.
IMHO, don't even bother starting it unless you're gonna ride. Like others here have said, you need to put a load on that new engine.
Warm-up isn't necessary unless it's below like 50 degrees, and even then, a minute is plenty.
Warm-up isn't necessary unless it's below like 50 degrees, and even then, a minute is plenty.
Wayne z, I hope and believe that you are right about these cylinders being produced rough for break-in porpoises. I have had many new Hondas in the past ( Three cars, three motorcycles and two outboard motors. ) and I’ve never seen one smoke when new.
I am using 30 weight oil on the first run (had no other oil at the time) but will change to 10W 30 at the next change. I will not use synthetic for the first 10 - 20 tanks of gas. I thought I would warm it up a couple of time before my first ride. I will not start it again before the first ride except to test he fuel pump. I know how important warm-up is with a strait rate oil. I will change oil after the first ride.
I hope I will not have to remove the tank and attach it to the top of the engine before the ride. It is a lot of work switching it back the way I have it now. And the engine is SO TALL with the tank on, it looks like a 250cc!
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The pump I installed is; Manufacturer; WALB, Product # FPC-1, whatever that is. It looks like the one for the GXH50 and Wards Lawn Power EQT said they thought it is the same company that make the Honda pump, I don’t think it is. I hope they will allow me to return it. It’s been almost a month since I bought it, 80 miles away in Gilbert AZ. I won’t be able to get back there till the 27th. Does anyone know the part number for the Honda pump and how much it could cost?
I am using 30 weight oil on the first run (had no other oil at the time) but will change to 10W 30 at the next change. I will not use synthetic for the first 10 - 20 tanks of gas. I thought I would warm it up a couple of time before my first ride. I will not start it again before the first ride except to test he fuel pump. I know how important warm-up is with a strait rate oil. I will change oil after the first ride.
I hope I will not have to remove the tank and attach it to the top of the engine before the ride. It is a lot of work switching it back the way I have it now. And the engine is SO TALL with the tank on, it looks like a 250cc!
.The pump I installed is; Manufacturer; WALB, Product # FPC-1, whatever that is. It looks like the one for the GXH50 and Wards Lawn Power EQT said they thought it is the same company that make the Honda pump, I don’t think it is. I hope they will allow me to return it. It’s been almost a month since I bought it, 80 miles away in Gilbert AZ. I won’t be able to get back there till the 27th. Does anyone know the part number for the Honda pump and how much it could cost?
I looked in the parts manuals for the GXH50 type engines and found these fuel pumps listed;
16700-ZT3-300 for serial number extensions of QHA, QHE or QHM
16700-ZT3-013for serial number extensions of QHA, QHA/A, QHA/B, QHE, QHE/A, QHE/B, QHM/A
16700-ZL8-013 for serial number extension of VSW4
My guess is that 16700-ZT3-013 is most likely the correct number. But that is only a guess.
16700-ZT3-300 for serial number extensions of QHA, QHE or QHM
16700-ZT3-013for serial number extensions of QHA, QHA/A, QHA/B, QHE, QHE/A, QHE/B, QHM/A
16700-ZL8-013 for serial number extension of VSW4
My guess is that 16700-ZT3-013 is most likely the correct number. But that is only a guess.
