Engine can't run extended period of time.

[ptnov]

Hi,

When I'm driving my vmax for more than 45min + it seems to have a rough idle when i get back in traffic och slow down. This sometimes causes the bike to shut down. Keeping the RPMs near 1500 seem to help, but it's still rough. The bike doesn't have any hot start problems or problem starting the bike when it shuts down as long as i rev it.

First I thought it was a carb issue since it leaked through carb 2, but I've since done the peashooter, rebuilt the carbs and synced it. I've also ordered new rubber inlets, to replace cracked one. Rubbers haven't arrived yet though. Problems still here. Could cracked boots cause this?

I can drive in traffic when i just start riding, and let the temp go to redline about 3-4 times before the rough idles comes...

Does anyone know what kind of problem this is?

Thanks!

 

[alorio1]

Your charging system is not supplying enough voltage to your electrical system. Check voltage at the battery at idle speed and then check voltage again @ 2500 RPM and report back readings. There is a good How to in the electical section by RAwarrior.....

 

[06VMAXIMUS]

Sounds electrical to me. Coils cracked and heating up might be causing them to fail? I would also put a voltmeter on the battery and check it with bike off, then with bike running and see what shes putting out.

 

[KJShover]

+1

Sounds like R/R issues. You might be able to fix it with the simple addition of some heavier gauge, stranded wire.

Yesterday I got bit by the hot start demon, while riding around town in 90+ degree weather. Needless to say tonight when everything cools down a bit, I'm going to be doing the mod. If that doesn't work, I just may put a different R/R on the bike.


.

 

[ptnov]

+1

Sounds like R/R issues. You might be able to fix it with the simple addition of some heavier gauge, stranded wire.

Yesterday I got bit by the hot start demon, while riding around town in 90+ degree weather. Needless to say tonight when everything cools down a bit, I'm going to be doing the mod. If that doesn't work, I just may put a different R/R on the bike.


.

Sorry if I don't understand which wires should be replaced? and with what kind of wire? Is this the COP thing?

 

[ptnov]

Gonna check voltage and wires soon as possible

 

[Dr.n2o]

Make sure you're charging system is ok first. I can tell you that once I got rid of the stock coils and did c o p mod with an odyssey battery, all that ******** stopped...the stock coils suck really bad....good luck man

 

[KJShover]

Sorry if I don't understand which wires should be replaced? and with what kind of wire? Is this the COP thing?

Basically, Your beefing up the pos and ground wires and running them directly from the R/R to the pos and negative of the battery. I still run coils and my battery is solid, but my charging needs some help.

The ignition will act all goofy with the battery getting low, causing symptoms that you have described. keep riding and it will suck the life from your battery and when you shut it off, you'll have a low battery to try and start the bike with.

Main thing is baby steps, No need to spend the $ unless you have to. Start with seeing how well your bike's charging system is working. Then work from there. It's allot cheaper to by wire and fittings first, then move on to R/R's, batteries, etc..

With the meter on my bike after yesterday's deal, was 12.5v static, just sitting there. Then when I turned the bike on it dropped to the 11's. When I started at a 800 rpm idle I was 12.2v, revving it up to 3k I only cracked 12.7v. I have a charging issue. It should have been in the 14's at 3k rpm.

This explains why my bike had a few burps and then wouldn't restart when I shut it off. The normal electrical requirements plus the fan being on taxed by system too much, and it couldn't keep up with the draw.

So I have a bit of heavier gauge wire and such to replace the other, smaller wire with.

If you do a search for "Hot Start" you will come up with a few threads that will further explain whats going on. It's 93deg out now and my garage is over 100 so I'm not going to do anything today. But I'm planning on a write up with pictures when I do fix it.

Here is a good post to read.

http://vmaxforum.net/showthread.php?t=19108

 

[davidon]

Make sure you're charging system is ok first. I can tell you that once I got rid of the stock coils and did c o p mod with an odyssey battery, all that ******** stopped...the stock coils suck really bad....good luck man

+1 COP mod seems to have solved the hot stall. Check Johans site for an idea of the wiring and R/R mods that should be done to help charging problems. He is in Sweden as well.

 

[srk468]

Do a search on the "crimp fix" this helped mine a bunch, even if your coils are cracked and need replaced the crimp fix is worth doing. I also did as was mentioned and tied into the hot wire out of the regulator and ran a 10 gauge wire with a fuse to the positive battery post and I also cleaned the surfaces behind the left passenger peg (where it grounds) and I never have any charging issues now.

Sent from my ADR6425LVW using Tapatalk 2

 

[95spfldmax]

Your charging system is not supplying enough voltage to your electrical system. Check voltage at the battery at idle speed and then check voltage again @ 2500 RPM and report back readings. There is a good How to in the electical section by RAwarrior.....

+1.....after that might suspect cracked coils.

 

[ptnov]

I did check today.

Got:
13.2V Idle
13.5-13.6V 2.5K RPM

Did the crimp fix:
Got:
13.4V Idle
13.7V 2.5K RPM

I used the choke to get the RPM. Haven't tried it in traffic though, so i don't know if the problem is solved...

 

[andyrpsmith]

You have the identicle problem I have been having the last few months. Poor idle after 45mins of riding, Perfect start and not obvious when cold and all fine above idle when revs rise. I checked charging system and had 13.8V. Did the crimp fix and now have 14.2v which is within spec. Cleaned all connectors, did the shotgun by cleaning out all pilot jets, balanced the carbs (had to buy the carb tune -highly recommended) this made a great improvement across the range and it only took a few minutes to do, raised the idle up to just under 1500rpm. All this helped but it still would start to dive below 1000rpm when hot at the lights and if idle set to 1000 as per spec it would eventually die.

What you must do is run the bike when it's very dark and I bet you will see a pyrotechnic display of HT arcing from the plug caps and leads to cylinder heads. This was happening mainly at the rear two cylinders on mine. I replaced the two rear HT leads and all the plug caps (NGK straight types). Problems seems to be solved. While fitting the rear leads I noticed the two rear coils have cracks in the bottom, I have added epoxy to the cracks but also ordered two new coils. I expect the front will have cracked but as they are a real pain to get out I may at some stage try the COPs mod. But at the moment it is running great.

 

[srk468]

I did check today.

Got:
13.2V Idle
13.5-13.6V 2.5K RPM

Did the crimp fix:
Got:
13.4V Idle
13.7V 2.5K RPM

I used the choke to get the RPM. Haven't tried it in traffic though, so i don't know if the problem is solved...

Was this with the fan running and everything on? That's plenty of juice so I'd look at the wires as suggested in the post above and also inspect your factory coils, might have cracked one or more of them..

Sent from my ADR6425LVW using Tapatalk 2

 

[Fire-medic]

I just checked ronayres pricing http://www.ronayers.com/ELECTRICAL-1-C138518.aspx for two ignition coils, $144 + shipping. Why didn't you get the COP's instead? I think you could have bought a set of 4 stick coils for what you paid for two OEM-style. They are much-easier to troubleshoot or replace, should it become needed.

Your other maintenance things are good ones, glad you picked-up some volts (said Reddy Kilowatt). I have used an evening darkness to show deficiencies in the shielding of the ignition system, and on-occasion, it looked like a van de graff generator.

You have the identicle problem I have been having the last few months. Poor idle after 45mins of riding, Perfect start and not obvious when cold and all fine above idle when revs rise. I checked charging system and had 13.8V. Did the crimp fix and now have 14.2v which is within spec. Cleaned all connectors, did the shotgun by cleaning out all pilot jets, balanced the carbs (had to buy the carb tune -highly recommended) this made a great improvement across the range and it only took a few minutes to do, raised the idle up to just under 1500rpm. All this helped but it still would start to dive below 1000rpm when hot at the lights and if idle set to 1000 as per spec it would eventually die.

What you must do is run the bike when it's very dark and I bet you will see a pyrotechnic display of HT arcing from the plug caps and leads to cylinder heads. This was happening mainly at the rear two cylinders on mine. I replaced the two rear HT leads and all the plug caps (NGK straight types). Problems seems to be solved. While fitting the rear leads I noticed the two rear coils have cracks in the bottom, I have added epoxy to the cracks but also ordered two new coils. I expect the front will have cracked but as they are a real pain to get out I may at some stage try the COPs mod. But at the moment it is running great.