Help vs1400 glp 93 rear cylinder cold

[Tim1400]

Hi guys new to this page but have a ongoing problem. I have vs1400 1993 rear cylinder is colder than the front and exhaust dont sound the same. Its at the mechanics and he has run out of ideas. We checked the 3 yellow wires that some 1 has suggested, carbs are synced, the other day the decomp issue stoped the bike from firing unpluged the decomp wire under the seat and bike started. Seems like the rear cylinder isn't getting enough spark and the stator was checked and is fine. Also when the bike was running it would jolt like surging in and out of power. Cylinders and compression is good. Any ideas? Thanks in advance

[Lechy]

Start the machine, when it is warm feel the exhaust pulses on the palm of your hand, if they are different you still need to do a correct carb synch. A lot of bike mech's don't understand that there are 2 adjustments to be made, idle and running. There is a video in one of my posts in the "how to" section.

http://intruders-alert.com/viewtopic.php?f=32&t=4139


[emoji41]

[Tim1400]

Ok il give it a ago then update. But also the rear coil has spark but when the bike is running and you un plug the rear coil it makes no difference to the way the bike was running

[enforcer]

Ok il give it a ago then update. But also the rear coil has spark but when the bike is running and you un plug the rear coil it makes no difference to the way the bike was running

That's because your probably running on one cylinder. And I doubt it has anything to do with the coil. It's going to be a carb sync. Far enough out and 1 cylinder can completely stop firing and the other will pull it along.

[jonnycando]

Mine did that before I had it synced...actually the one cylinder wasn't plum dead, but it was way short of where it needed to be.

[Tim1400]

Ok bike has been synced but still a spark issue, like i said when we unplugged the wires under the seat for decomp it started, but wouldnt start when the wires where connected it stopped spark to both cylinders and when its running its like a spark issue in the rear cylinder. Coils have been checked and fine spark plugs fine and stator is fine

[enforcer]

Ok bike has been synced but still a spark issue, like i said when we unplugged the wires under the seat for decomp it started, but wouldnt start when the wires where connected it stopped spark to both cylinders and when its running its like a spark issue in the rear cylinder. Coils have been checked and fine spark plugs fine and stator is fine

Are you sure it's the decomp? The decomp only works when the engine is turning over. After it starts, the system is non existent. Perhaps it's sticking open? But there's no way it can impeed your spark. My guess is it's not the decomp you're unplugging. Pictures really help in this situation.

[Lechy]

Try feathering the plug, start the machine, get her idling, a pair of Marigold rubber gloves, pull the plug cap off and slowly pull the cap out from a connection to the plug to say 1/2" gap. If the machine starts to fire correctly then the problem will possibly be #1: bad plug. #2 weak coil. #3 bad HT lead. #4: faulty plug cap. Almost forgot, take the machine to a dark area at night, pull the chrome cover, start her up and look down into the plug well for a tracking spark.

[emoji41]

[Truder85]

Take the front plug and switch it with the rear to see if the rear fires up.
I dont know how you've check youre plugs but even if there is spark does not mean that the spark is strong enough.
Also might be that the float is stuck close preventing gas to get into the cylinder.
And in some rare cases the air filter might be so dirty that it does not let enough air in.
Just my opinon good luck.

[Thunderbirds1]

Hi guys new to this page but have a ongoing problem. I have vs1400 1993 rear cylinder is colder than the front and exhaust dont sound the same. Its at the mechanics and he has run out of ideas. We checked the 3 yellow wires that some 1 has suggested, carbs are synced, the other day the decomp issue stoped the bike from firing unpluged the decomp wire under the seat and bike started. Seems like the rear cylinder isn't getting enough spark and the stator was checked and is fine. Also when the bike was running it would jolt like surging in and out of power. Cylinders and compression is good. Any ideas? Thanks in advance

Hey Tim, welcome to the board...

Over the past 15 years I've had my '93 1400, I've experienced this in some way or the other. Once it was the front cylinder, most the other times it was the rear.

Most of my cases it was the carb. The front carb's diaphragm recently had gummed up so it wouldn't move a bit, probably some bad gas or so. Some good cleaning took care of that. 'Probably should synch the carb's one day, but so far, CLEANING, CLEANING, CLEANING does the trick. I believe unless you do some changes, synching shouldn't have to be your first attempt to fix most carb issues.

The rear I had always managed to clog the screen filter right befor the float and reservoir chamber. Years ago I had a custom Kevlar tank made, bypassed the petcock with some fuel lines and didn't install a inline fuel filter because I was so anxious to ride (big mistake). Well, long story short, I had sucked some debris in from the tank and they clogged this very screen, as well as the jets. Result, no fuel to the rear carb. I had to perform the following carb cleaning 3 or 4 times until I installed an inline filter...

BTW, the fuel line runs from the fuel pump to the rear carb and T's off to continue to the front carb. Luckily that's where my clog stayed so I had to only clean the rear. To do this, you will have to remove the carb, take the reservoir bowl off, carefully remove the float hinge pin (secured by a small screw) remove the float, remove another small screw under the float and the carefully pull the screen housing out (I used some worn out pliers to not to damage the housing).







This is years ago, I need to see if I have the pictures on the old laptop somewhere...

Let us know if and how you fixed it, maybe it's news to some of us.

Happy riding.

Lee

[Tim1400]

Give every thing suggested a go this week then give u guys an update. Thanks for the help

[hurleyfrank]

wow, nice post! i just realised that our bike don't have any kind of fuel filter. and since i'm not somebody who like to play with those carbs too often, i plan to install one ASAP. I think the best place could be right at the entrance of the fuel pump (hidden). do anyone happen to know the size of the fuel line at the entrance of the fuel pump? i could check myself but i don't want to take it apart to measure and again to install.. 1/4, maybe?

[enforcer]

wow, nice post! i just realised that our bike don't have any kind of fuel filter. and since i'm not somebody who like to play with those carbs too often, i plan to install one ASAP. I think the best place could be right at the entrance of the fuel pump (hidden). do anyone happen to know the size of the fuel line at the entrance of the fuel pump? i could check myself but i don't want to take it apart to measure and again to install.. 1/4, maybe?

6mm or 5/16". Metric bike after all.

[Thunderbirds1]

wow, nice post! i just realised that our bike don't have any kind of fuel filter. and since i'm not somebody who like to play with those carbs too often, i plan to install one ASAP. I think the best place could be right at the entrance of the fuel pump (hidden). do anyone happen to know the size of the fuel line at the entrance of the fuel pump? i could check myself but i don't want to take it apart to measure and again to install.. 1/4, maybe?

The petcock inside the fuel tank has screens and then the two in the carb reservoirs... Better than none, but I wouldn't give them any micron ratings by any means.

Another place is after the fuel pump, going upwards to the first carb. Plenty of line there.

Had problems more than once, I know what you mean.

Lee

[Tim1400]

Ok no progress got no spark at all at the moment, all indicators are the cdi. So purchased a dynatek 3000 ignitor. I live in Australia so waiting to come from States. I was thinking of changing the coils while at it, but not sure what dynatek coils match a d3k3-1. In US found after market coils from a mob called caltric has any one used them? Tia

[enforcer]

Ok no progress got no spark at all at the moment, all indicators are the cdi. So purchased a dynatek 3000 ignitor. I live in Australia so waiting to come from States. I was thinking of changing the coils while at it, but not sure what dynatek coils match a d3k3-1. In US found after market coils from a mob called caltric has any one used them? Tia

Coils rarely fail. Make sure you test them before replacing. Caltric coils are generic branded. OEM coils are better.

[Fred]

Your not listening your synch is way out. your front Cylinder has been turned up so much that the rear does not have to do any thing. It seems like it is misfiring but its just not pulling its weight and feels like its missing.

Think of a tandem bike and the guy on the back is not pedaling hard enough. Looks like it but he is not pulling any power. The guy on the front is doing all the work.

Even so called mechanics dont get this sinch system.