Bashan motomax - nearly unusable

TestYourMight · 06-23-2020, 09:52 PM

Bike has 500 miles. Got stranded the past 3 days because of engine bogging in 5th gear at constant throttle. The bike shuts off for about 5-10 min and starts again after that. The second I get up to cruising speed in 5th, it will bog and die again. Anyone know what this could be? I'm thinking it's something to do with the needle in the carb.

Mister104 · 06-23-2020, 11:10 PM

I’d say you have a carburetor issue. Probably a simple adjustment.

TestYourMight · 06-23-2020, 11:33 PM

Quote:

Originally Posted by Mister104

I’d say you have a carburetor issue. Probably a simple adjustment.

I'm thinking you're right. I'm using the stock keihin pz30 with a 110 main, stock pilot, and 1.5 turns out. Rejetted at 200 miles. Stock airbox, stock exhaust. A little more history: The bike started dying in 5th gear four days ago. A few days later, after these symptoms persisted (engine bog when cruising around 50-55mph), it wouldn't start at all. Last night I removed the carb and found that the needle was detached from its black housing cylinder, and had fallen down into the carb. I pulled everything apart, found out the E-clip had detached from the needle, and reassembled everything correctly. Bike worked better than ever for 24hrs, not showing a single problem. Then today I was riding home from work, and it died in 5th again at 52mph. Waited 10 min, started the bike and rode home in 4th. I'm going to pull apart the carb now and see if I notice anything funny.

I wonder if I'm running too rich? But if that were the case, wouldn't the problems happen in other gears? This is my first bike, so I'm still learning. Thank you for any help.

culcune · 06-23-2020, 11:43 PM

If you haven't already done so, and if you haven't, before messing with the carb, look up how to set the valve lash. These can get pretty tight, and sometimes come tight out of the box.

**JerryHawk250** · 06-24-2020, 08:59 AM

Quote:

Originally Posted by culcune

If you haven't already done so, and if you haven't, before messing with the carb, look up how to set the valve lash. These can get pretty tight, and sometimes come tight out of the box.

^What he said ^

franque · 06-24-2020, 04:00 PM

I'd check your plug, too. I've noticed that when your valves are tight, or the plug used up, you'll get the symptoms you're describing.

Oddball Matt · 06-24-2020, 04:07 PM

One thing to check is the tank breather (provided this has one, not familiar with the model)

Sometimes the breather hose can get kinked or clogged and it pulls a vacuum into the tank thus starving the carb of fuel. Wait 10-15mins and the cap seal lets in enough air to fill the bowl, bike starts, rinse and repeat. Next time it bogs down open the fuel cap, if you get a *schup* then that's your problem.

TestYourMight · 06-24-2020, 04:23 PM

Thank you so much everyone. My valve feeler gauges should be here today. I will set valve lash, check the plug, and tank breather tonight after work and update you all. This community is seriously the best.

SilverBullet51 · 06-24-2020, 06:34 PM

I 2nd what oddball said, an easy way to check and see if it's the breather, is after it stalls pop the gas cap off. If it fires right back up you're getting vapor lock, and your tank breather is restricted some how.

TestYourMight · 06-25-2020, 07:33 PM

Update: Checked the spark plug (NGK) and it was pretty loose. Didn't even have to break it free, it just turned freely. I feel dumb. Adjusted the valve clearance with a cold engine (had a bit of difficulty finding TDC). Initially, I noticed both were extremely tight with no play whatsoever. Set both to 0.0025". Pulled carb needle housing apart once again, and seated the E clip and the V clip nice and snug (I hadn't pressed the V clip all the way down & flush against the bottom before). Tank breather had no issues. Afterwards, I changed the oil with Amsoil synthetic 20w-50, and saw some speckles in the old stuff with an LED shining at it. Go figure, it started pouring rain here in NE Florida as I was fastening the last fairing. Bummer, but I'll have to wait to ride her after. I did let her idle for about 5-7 min and I noticed the new ticking noise coming from the valves (which I think is good). I'm guessing the ticking will reduce once the engine warms up. Furthermore, upon revving, there is no more high pitched rattle between ~3k-4k rpm like there used to be. Could this be because the valves were too tight before? Feeling pretty optimistic, but the true test will be coasting in 5th for a few miles.

NzBrakelathes · 06-26-2020, 11:30 AM

TestYourMight · 06-29-2020, 05:33 PM

Update: bike bogged the very next day on my way home from work after all the adjustments. Bummer. But you know what... funny thing is, it poured rain all day while my bike sat in my work parking lot. Come to think of it, it's rained nearly every day for the past couple of weeks here in NE Florida. Thinking back, I'm pretty sure the bike had the bogging issues every single time it got soaked. Could it be possible that water is causing the plug not to spark correctly? Has anyone else experienced problems with a wet/soaking wet bike?

Edit: because I've now let the bike dry for 24 hrs and it runs perfectly fine. It's a beautiful sunny day today. Riding all around town right now for the past hour and no bogging issues whatsoever

franque · 06-29-2020, 05:42 PM

Check whether your grounds are tight, and make sure to weatherproof your connectors with a good dielectric grease, the rain isn't directly affecting the plug, potentially your coil is getting wet/isn't grounded properly?

ChrisWNY · 06-29-2020, 05:45 PM

Rain water shouldn't be able to make its way into the engine, unless there is a leak somewhere or things aren't bolted down well enough. Water can get in through gaps or leaks in hoses, possibly through the airbox or intake into the carb, depending on how your bike is set up. Any way you slice it, you don't want any water getting into your fuel lines, air intake, gas tank, etc. etc. The engine itself is sealed with gaskets and everything else that carries air or fuel to the engine should not provide an entry way for water. You should be able to give your bike a wash with the garden hose and take off right after you're done to help dry the bike off with no water entering the engine. Electrical connections (wire harnesses, brake cables, turn signal wire connections) should all be waterproofed and/or away from water exposure as well.

franque · 06-30-2020, 06:06 AM

Water in the engine won't do that. Period. That's why I offered the explanation that I did. Water getting into the oil (unless it's a huge amount) will evaporate out, and water in the combustion chamber will just clean the combustion chamber, in fact, it's an old trick to decoke an engine to run it while spraying water through a spray bottle directly into the intake.

06-23-2020, 09:52 PM	#1
TestYourMight Join Date: May 2020 Posts: 20	Bashan motomax - nearly unusable Bike has 500 miles. Got stranded the past 3 days because of engine bogging in 5th gear at constant throttle. The bike shuts off for about 5-10 min and starts again after that. The second I get up to cruising speed in 5th, it will bog and die again. Anyone know what this could be? I'm thinking it's something to do with the needle in the carb.
	0

06-23-2020, 11:43 PM	#4
culcune Join Date: May 2006 Location: Yuma, Arizona Posts: 9,035	If you haven't already done so, and if you haven't, before messing with the carb, look up how to set the valve lash. These can get pretty tight, and sometimes come tight out of the box. __________________ "They say that life's a carousel, spinning fast you got to ride it well..." TGB Delivery Scooter 150 TMEC 200 Enduro--carcass is sadly rotting in the backyard
	5

06-24-2020, 04:07 PM	#7
Oddball Matt Join Date: Jan 2020 Location: Vääksy, Finland Posts: 401	One thing to check is the tank breather (provided this has one, not familiar with the model) Sometimes the breather hose can get kinked or clogged and it pulls a vacuum into the tank thus starving the carb of fuel. Wait 10-15mins and the cap seal lets in enough air to fill the bowl, bike starts, rinse and repeat. Next time it bogs down open the fuel cap, if you get a schup then that's your problem. __________________ 2004 Longjia Grido 50 scooter 1999 Cagiva Mito 125 Evo, Yamaha XV125 engine, Ducati SS fairings, getting turboed 1993 Yamaha GTS 1000 Ex:Bashan BS200-S7 `07 Streetfighter-quad
	3

06-29-2020, 05:45 PM	#14
ChrisWNY Join Date: Jul 2018 Posts: 212	Rain water shouldn't be able to make its way into the engine, unless there is a leak somewhere or things aren't bolted down well enough. Water can get in through gaps or leaks in hoses, possibly through the airbox or intake into the carb, depending on how your bike is set up. Any way you slice it, you don't want any water getting into your fuel lines, air intake, gas tank, etc. etc. The engine itself is sealed with gaskets and everything else that carries air or fuel to the engine should not provide an entry way for water. You should be able to give your bike a wash with the garden hose and take off right after you're done to help dry the bike off with no water entering the engine. Electrical connections (wire harnesses, brake cables, turn signal wire connections) should all be waterproofed and/or away from water exposure as well. __________________ 2018 RPS Hawk 250cc Mods so far: 1. Mikuni VM26 Carburetor w/#115 main jet 2. 17T/45T JT sprockets 3. JT 428 X-ring chain 4. Air box mod 5. Hawk Digital Cluster 6. Aftermarket IMS shift lever 7. Performance Aftermarket Exhaust 8. 295mm Nitrogen Gas Monoshock, 20W oil front forks
	0

06-23-2020, 11:10 PM	#2
Mister104 Join Date: Nov 2019 Posts: 23	I’d say you have a carburetor issue. Probably a simple adjustment.
	0

06-24-2020, 04:00 PM	#6
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	I'd check your plug, too. I've noticed that when your valves are tight, or the plug used up, you'll get the symptoms you're describing.
	1

06-24-2020, 04:23 PM	#8
TestYourMight Join Date: May 2020 Posts: 20	Thank you so much everyone. My valve feeler gauges should be here today. I will set valve lash, check the plug, and tank breather tonight after work and update you all. This community is seriously the best.
	1

06-24-2020, 06:34 PM	#9
SilverBullet51 Join Date: Apr 2017 Location: Plainwell, MI Posts: 60	I 2nd what oddball said, an easy way to check and see if it's the breather, is after it stalls pop the gas cap off. If it fires right back up you're getting vapor lock, and your tank breather is restricted some how.
	2

06-25-2020, 07:33 PM	#10
TestYourMight Join Date: May 2020 Posts: 20	Update: Checked the spark plug (NGK) and it was pretty loose. Didn't even have to break it free, it just turned freely. I feel dumb. Adjusted the valve clearance with a cold engine (had a bit of difficulty finding TDC). Initially, I noticed both were extremely tight with no play whatsoever. Set both to 0.0025". Pulled carb needle housing apart once again, and seated the E clip and the V clip nice and snug (I hadn't pressed the V clip all the way down & flush against the bottom before). Tank breather had no issues. Afterwards, I changed the oil with Amsoil synthetic 20w-50, and saw some speckles in the old stuff with an LED shining at it. Go figure, it started pouring rain here in NE Florida as I was fastening the last fairing. Bummer, but I'll have to wait to ride her after. I did let her idle for about 5-7 min and I noticed the new ticking noise coming from the valves (which I think is good). I'm guessing the ticking will reduce once the engine warms up. Furthermore, upon revving, there is no more high pitched rattle between ~3k-4k rpm like there used to be. Could this be because the valves were too tight before? Feeling pretty optimistic, but the true test will be coasting in 5th for a few miles.
	6

06-26-2020, 11:30 AM	#11
NzBrakelathes Join Date: Jun 2016 Location: Hell Posts: 2,408
	0

06-29-2020, 05:33 PM	#12
TestYourMight Join Date: May 2020 Posts: 20	Update: bike bogged the very next day on my way home from work after all the adjustments. Bummer. But you know what... funny thing is, it poured rain all day while my bike sat in my work parking lot. Come to think of it, it's rained nearly every day for the past couple of weeks here in NE Florida. Thinking back, I'm pretty sure the bike had the bogging issues every single time it got soaked. Could it be possible that water is causing the plug not to spark correctly? Has anyone else experienced problems with a wet/soaking wet bike? Edit: because I've now let the bike dry for 24 hrs and it runs perfectly fine. It's a beautiful sunny day today. Riding all around town right now for the past hour and no bogging issues whatsoever
	0

06-29-2020, 05:42 PM	#13
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Check whether your grounds are tight, and make sure to weatherproof your connectors with a good dielectric grease, the rain isn't directly affecting the plug, potentially your coil is getting wet/isn't grounded properly?
	0

06-30-2020, 06:06 AM	#15
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	Water in the engine won't do that. Period. That's why I offered the explanation that I did. Water getting into the oil (unless it's a huge amount) will evaporate out, and water in the combustion chamber will just clean the combustion chamber, in fact, it's an old trick to decoke an engine to run it while spraying water through a spray bottle directly into the intake.
	3