overheat/stall

so now that the weather has warmed up, my VMax has been riding the upper limit of the temp gauge when i'm in traffic. Today, while at a light in neutral, the idle dropped down under 1k rpm and began to cough and sputter. I held the accelerator to around 1.1k rpm and it was fine, but when I'd let off, sometimes it would stall. then of course there was the hard start, but it did start, barely. Once the bike cooled off, no problems whatsoever.

Have any of you experienced this before? Should I raise my idle for summer?

Any help would be greatly appreciated!

Don

Manual fan switch and/or a lower temp thermostat might fix you up.

sounds like the problem i was having.
If its not the stator, maybe pickup coils
http://www.vmaxforum.net/showthread.php?t=13212

I would raise the idle, I had the same problem and found the fan taxed the electrical system so much it began to stumble and misfire and eventually die. I recently done the R1 RR mod which helped dramatically, also went to a four pole starter, which also made a big difference in hot starts. If you have a volt meter you can verify how much your voltage is being dragged down when the fan comes on and stays on for a while just as if you were in heavy traffic. One more thing I did 24 years ago was removed my thermostat which allowed the engine to run cooler a lot longer before it climbed fast to reach normal operating temp. I have not seen any ill effects by removing the thermostat 24 yrs ago. Some members may or may not agree with this and have good critical feedback on removing thermostat so may have done it themselves, all I know is it helped my problems before the 4 pole starter came out and the R1 mod was discovered. You have a whole host of information here on the forum with very knowledgeable people, some considered as Gen 1 Guru's which I am faaaaaaaar from being in their class, so take the info given by the members and sort thru it and use what you agree with. Most of the members on here with older Gen1s have had the same problems you are encountering.

I had the exact symptoms until after I got my voltage problems fixed. I did all the little connector things to increase the voltage back closer to OEM specs and also did the larger battery box mod and fitted the big battery. All my idle problems went away and the bike has never overheated since.

KJShover said:

Manual fan switch and/or a lower temp thermostat might fix you up.

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Too hot Don. There is a tiny black dot on the temp gauge. You should be close.
+ 1 to the override switch or lower temp fan switch which I like. The fan will run more though, and like Joe said, tax your electrical system a bit. Not a problem if charging system is in good condition.Either a fan switch for an '88 Nissan Sentra
or Borg Warner TFS545. You'll have to re-use your o-ring. A good flushing and new anti freeze is good practice too.
Steve-o

sdt354 said:

A good flushing and new anti freeze is good practice too.
Steve-o

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Given that the cooling system has had 23 years to build up some crud in it then I would try one of the proprietary cooling system flushes to make sure what you have is performing as well as it can.
As Steve suggests, also replace the anti freeze as well.

Whilst you may ultimately need to fit an over ride or switch that cuts the fan in earlier this is side stepping the cause.

Thanks Guys. I'm going to pick up the borg warner tomorrow and install it. Pursuant to a different thread, my new tires came in today, and I hope to have them mounted tomorrow too. Went with the Metzler 880's, 170 rear and stock front.

Everyone have a safe holiday weekend, and thanks again for the great advice.

I have always veered away from radiator flush because its so hard to get it out of your system thoroughly. You have to bring the engine temp up so the thermostat opens for each flush to get it all out, which will take several flushes in my opinion. If its not completely flushed it could eat the head gaskets up. So its a good idea to replace your coolant regularly. Just my .02 cents

MaxMidnight said:

Given that the cooling system has had 23 years to build up some crud in it then I would try one of the proprietary cooling system flushes to make sure what you have is performing as well as it can.
As Steve suggests, also replace the anti freeze as well.

Whilst you may ultimately need to fit an over ride or switch that cuts the fan in earlier this is side stepping the cause.

Click to expand...

The Vmax will run hot in traffic, a fan override switch will take care of that, stalling when hot enough for the fan to come on is more than likely the charging system not putting out enough voltage to satisfy the electronic ignition.

That's interesting. I'm wondering if the new high power bulb i just put in my headlight is affecting it. I've been riding highbeam all the time, but the only time the bike starts to cough is when the temp gauge is near the red line.

I put the different temp switch in mine years ago to activate the fan earlier on the dial closer to the little black dot. Mine would begin blubbering and missing out at idle any time the fan kicked on, and the bike wasn't even over heated yet. Then while I was feathering the throttle in traffic trying to keep it from stalling out and dying, I'd watch the temp slowly climb past the red line and have to pull into a parking lot to allow the bike to cool.

I had already installed a new thermostat and changed out the antifreeze mix as well. No matter what I did, the bike would begin missing out and trying to stall at engine speeds below around 2000-2500rpms each and every time the fan came on.

After the electrical connection cleaning and tweeking, plus the bigger battery, all is OK (knock on wood). No more overheating. No more missing and stalling below 2500rpms.

I suspect, in my case at least, my CDI was not operating correctly with the lower voltage and the addt'l draw from that fan caused it to start malfunctioning.

As Jay Leno would say "EXACTLY , EXACTLY"............

jfeagins said:

I put the different temp switch in mine years ago to activate the fan earlier on the dial closer to the little black dot. Mine would begin blubbering and missing out at idle any time the fan kicked on, and the bike wasn't even over heated yet. Then while I was feathering the throttle in traffic trying to keep it from stalling out and dying, I'd watch the temp slowly climb past the red line and have to pull into a parking lot to allow the bike to cool.

I had already installed a new thermostat and changed out the antifreeze mix as well. No matter what I did, the bike would begin missing out and trying to stall at engine speeds below around 2000-2500rpms each and every time the fan came on.

After the electrical connection cleaning and tweeking, plus the bigger battery, all is OK (knock on wood). No more overheating. No more missing and stalling below 2500rpms.

I suspect, in my case at least, my CDI was not operating correctly with the lower voltage and the addt'l draw from that fan caused it to start malfunctioning.

Click to expand...