Stalling around ~50mph - Honda Shadow Forums : Shadow Motorcycle Forum

JackC1027 · 04-18-2012, 09:58 AM

I bought my bike a few months ago, and have put a bit of work into it, seems like it has been sitting for a few years+. I flushed the coolant, recored the radiator, oil change, thermostat changed, spark plugs changed, etc. I notice now that when I am about 50mph in 5th gear it seems to spudder a bit and that I lose a TON of power, when I try and speed up more, its struggling.

I plan on cleaning (or possibly rejetting the carbs, and removing the stock baffles) this weekend.

Any other ideas of what it could be?

ak-rider · 04-18-2012, 12:53 PM

Fuel tank vent could be plugged. Filter may be clogged.

"Captain D" · 04-18-2012, 01:53 PM

Welcome to Motorcycling!!!
Make sure you take a CLOSE look at the diaphrams in the carb tops whilst you got it in your hands...
That`s what symptoms mine started with when the diaphrams needed replacing and continually got worse until it would barely run at all...
Even tiny holes/cracks in the rubber make it run rough...
Good Luck
Dennis

JackC1027 · 04-18-2012, 06:04 PM

Quote:

Originally Posted by ak-rider

Fuel tank vent could be plugged. Filter may be clogged.

I'll check the fuel tank vent. I have recently changed the fuel filter.

Quote:

Originally Posted by "Captain D"

Welcome to Motorcycling!!!
Make sure you take a CLOSE look at the diaphrams in the carb tops whilst you got it in your hands...
That`s what symptoms mine started with when the diaphrams needed replacing and continually got worse until it would barely run at all...
Even tiny holes/cracks in the rubber make it run rough...
Good Luck
Dennis

Thanks. I just ordered a rejet kit or my bike, and plan on cleaning the carbs/rejecting this weekend. Hopefully this is everything I will need to get it running proper.

93gc40 · 04-18-2012, 06:13 PM

STRONGLY, recommend fixing the problem. Before messing with either the exhaust or jets.

JackC1027 · 04-18-2012, 06:42 PM

Quote:

Originally Posted by 93gc40

STRONGLY, recommend fixing the problem. Before messing with either the exhaust or jets.

I would like to fix it before. However I am not sure what exactly it is. The bike was sitting for quite awhile, so I am thinking it could be the carb needs cleaning.

mattyo · 04-18-2012, 10:19 PM

93gc40's point is to NOT rejet or remove baffles quite yet. Yes, definitely clean the carbs, check the air vent, check the diaphragms. I know it's annoying to not just do everything on the to-do list at once but this problem will become very clouded if you rejet and remove your baffles before figuring out what the problem is. Rejetting and exhaust mods change the whole dynamic of how the engine runs. The problem you're experiencing is not jet or exhaust related and that's why 93gc40 is strongly suggesting to not change those things yet until you've found the problem because it will be much more difficult to find if you change those things. As a wise man once said, change only one things at a time.

JackC1027 · 04-19-2012, 11:20 PM

Quote:

Originally Posted by mattyo

93gc40's point is to NOT rejet or remove baffles quite yet. Yes, definitely clean the carbs, check the air vent, check the diaphragms. I know it's annoying to not just do everything on the to-do list at once but this problem will become very clouded if you rejet and remove your baffles before figuring out what the problem is. Rejetting and exhaust mods change the whole dynamic of how the engine runs. The problem you're experiencing is not jet or exhaust related and that's why 93gc40 is strongly suggesting to not change those things yet until you've found the problem because it will be much more difficult to find if you change those things. As a wise man once said, change only one things at a time.

While I do understand, I really don't see how rejetting will hurt. I am eventually GOING to remove the baffles, and when doing so, I will also be rejetting. I figure since I am going to be ripping the cabs apart anyways to clean them, I might as well rejet since everything is out anyways. I don't want to pull the carb, clean it, reinstall, ride the thing for a week to test it, then repull the carb, rejet, reinstall, etc...

FreakShow · 04-20-2012, 12:22 AM

Working on carbs is like conducting a science experiment. In order to determine the true outcome/cause of a certain phenomenon it is vitally important to limit as many variables as possible.

Right now you have one massive unknown: Stalling around 50mph.
You also have numerous variables:
-dirty carbs
-diaphrams
-clogged jets
-air leak somewhere?
-fuel tank vent line clogged?
-a few that I may have forgotten

Basically, if you rejet now you're adding to the list of variables. Maybe a rejet will fix it. What if it makes it worse, OR adds an additional problem?

I just went through this the hard way with my buddy and his new-to-him '95 Suzuki GS500. We rebuilt the carbs and he insisted on installing new jets before we got the bike running first. A few weekends later we've got it running but wasted a CRAP ton of time because of setbacks caused by changing things before FIXING things.

Just my $.02. It's your bike to do with as you please. But be warned, if you rejet there is a chance you won't get it right the first time so be prepared to learn how to take the carbs out efficiently.

Schattenreiter · 04-20-2012, 07:35 AM

What size bike are we talking here. What happens if you drop back to fourth when you speed up? Does it still stall or not?

04-18-2012, 09:58 AM	#1 (permalink)
JackC1027 Senior Member Join Date: Feb 2012 Posts: 104	Stalling around ~50mph I bought my bike a few months ago, and have put a bit of work into it, seems like it has been sitting for a few years+. I flushed the coolant, recored the radiator, oil change, thermostat changed, spark plugs changed, etc. I notice now that when I am about 50mph in 5th gear it seems to spudder a bit and that I lose a TON of power, when I try and speed up more, its struggling. I plan on cleaning (or possibly rejetting the carbs, and removing the stock baffles) this weekend. Any other ideas of what it could be?

04-18-2012, 12:53 PM	#2 (permalink)
ak-rider Senior Member Join Date: Jun 2011 Location: Somewhere in Alaska Posts: 122	Fuel tank vent could be plugged. Filter may be clogged. __________________ Back in the saddle after too many years without a bike. Starting this leg of my journey with a 1997 VLX. Can't wait to see where the road takes me.

04-18-2012, 01:53 PM	#3 (permalink)
"Captain D" Senior Member Join Date: Jun 2008 Location: SW Georgia. Between Americus & Buena Vista - Ellaville and Plains Posts: 3,734	Welcome to Motorcycling!!! Make sure you take a CLOSE look at the diaphrams in the carb tops whilst you got it in your hands... That`s what symptoms mine started with when the diaphrams needed replacing and continually got worse until it would barely run at all... Even tiny holes/cracks in the rubber make it run rough... Good Luck Dennis __________________ `98 VT750 A.C.E. Motorcycle Rider Rights Activist www.mrf.org www.MSF-USA.org www.ABATEGA.org ABATE member 36yrs. http://www.ama-cycle.org/ Elect "Motorcycle friendly" government officials ONLY!

04-18-2012, 06:13 PM	#5 (permalink)
93gc40 Senior Member Join Date: Nov 2008 Location: Visalia, CA Posts: 4,360	STRONGLY, recommend fixing the problem. Before messing with either the exhaust or jets. __________________ 93 VT1100C Harley Killer (1150cc), VH Exhaust, 2mm sleeved and bored, Modified Heads and Valves, Adjustable Timing, Touring Seat, Baby Apes, Metzlers

04-18-2012, 10:19 PM	#7 (permalink)
mattyo Senior Member Join Date: May 2011 Location: Madison, WI Posts: 1,310	93gc40's point is to NOT rejet or remove baffles quite yet. Yes, definitely clean the carbs, check the air vent, check the diaphragms. I know it's annoying to not just do everything on the to-do list at once but this problem will become very clouded if you rejet and remove your baffles before figuring out what the problem is. Rejetting and exhaust mods change the whole dynamic of how the engine runs. The problem you're experiencing is not jet or exhaust related and that's why 93gc40 is strongly suggesting to not change those things yet until you've found the problem because it will be much more difficult to find if you change those things. As a wise man once said, change only one things at a time. __________________ 1983 vt750 - "Fra-Hankenstein" (restoration in progress, click for the full story)

04-20-2012, 12:22 AM	#9 (permalink)
FreakShow Senior Member Join Date: Sep 2011 Location: Bloomington/Macomb, IL Posts: 194	Working on carbs is like conducting a science experiment. In order to determine the true outcome/cause of a certain phenomenon it is vitally important to limit as many variables as possible. Right now you have one massive unknown: Stalling around 50mph. You also have numerous variables: -dirty carbs -diaphrams -clogged jets -air leak somewhere? -fuel tank vent line clogged? -a few that I may have forgotten Basically, if you rejet now you're adding to the list of variables. Maybe a rejet will fix it. What if it makes it worse, OR adds an additional problem? I just went through this the hard way with my buddy and his new-to-him '95 Suzuki GS500. We rebuilt the carbs and he insisted on installing new jets before we got the bike running first. A few weekends later we've got it running but wasted a CRAP ton of time because of setbacks caused by changing things before FIXING things. Just my $.02. It's your bike to do with as you please. But be warned, if you rejet there is a chance you won't get it right the first time so be prepared to learn how to take the carbs out efficiently. __________________ 2007 Spirit 1100, Hard Krome pipes, K&N, DynoJet Stage 1, Saddlemen Tattoo Slants, Switchblade Windshield Not enough miles...yet

04-20-2012, 07:35 AM	#10 (permalink)
Schattenreiter Senior Member Join Date: Oct 2008 Location: Eastern North Carolina Posts: 1,364	What size bike are we talking here. What happens if you drop back to fourth when you speed up? Does it still stall or not?

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