I just remembered this problem I had with my HO last winter, and thought I would see if you guys know what it is. My 96 670 never had this problem.

After starting it up, I have to let it sit and idle and warm up for a while. If I try to give it gas, the motor bogs and dies around 4500 rpm. The clutch just starts to engage, and sometimes it will move a little, then it just stops. If I let off before it dies too much, the engine comes back. A number of people last year suggested to me to replace the spark plug boots, they found they got dirty and caused this problem. I cleaned mine with electronic component cleaner, and it did nothing, even though there was a lot of black stuff in there.

The colder it was, the longer I had to let it warm up. Once it idled for a while, it would run fine.

Also.. what is the stock secondary setting? (A,B,C.. 1 - 6??). I picked up the sled late last year, and didn't check out the setup.. I don't know if it was screwed with.

Go to your dealer and get the one piece wire and boot from the series 3 motors, that will
definitely cure that problem. Thats what fixed mine.
I'm not sure what the stock setting for the secondary is but I'm using A6, You could try B6 or C6 also
and see what works best for you. Hope this helps.

Hi,

I had the same problem with my 98 summit X. My engine would cut out when it was cold, and would come back when the throttle was released. I gapped the spark plugs right ( .018") and that fixed the problem! ;)

They need to be warmed up before you ride them anyway but the prob will be fixed with new wires I think.

Series 3.. is that the new motors (say from a 2000 and up 700)? And by one piece, do you mean the plug boot and wire cannot be separated? Will it be a simple replacement, or will splicing be required at the coil?

Its a simple replacment with no splicing. Just sort of unscrew the old wire from the coil and turn and push the new on one. Just like its been done for years.

I dont have the bogging problem with the 98 500 but my plug wires are shot, Im gonna change them with NGK race wires because there RED. LOL...

I didnt quite like the 2 peice ones also.

Hey I had the same thing last year on my 99 HO. I changed the plugs out with new ones propertly gapped, and the problem went away. Like FIL said - make sure they are gapped to .018

:withstupid:

First things first. Before you waste any money, just gap the plugs.
If it still does it, then go with the new wires.

The first thing I did when I bought the sled was put new NGK plugs in it, gapped to .018".

I'll try replacing the wires.

Another question: The left handwarmer doesn't work. The end of the grip in bent/deformed, looks like the previous owner put the sled on its side (3 scratches on that side of hood too). While I am fixing/replacing the hardwarmer, are there any good aftermarket grips with handwarmers built in, or should I buy a replacement element and MXZX grips? I am sick of the hard slippery plastic grips. What have you guys done?

I don't know about using series III parts on a 670HO. Are you sure that would not slow it down?

Where talking about plug wires. It will work as long as its the right size.

Remove the plug wires from your 670 and check the wires AND cap together with an ohmmeter. Should be about 5K ohms resistence. Inside the cap there is a built in resister to allow proper spark. As long as the Series 3 wires have the same resistence you will be fine. "Black stuff" on your plugs and inside the caps show that something is moving around(plug cap) and getting worn. This can cause damage to the resister, impeding spark.