O.K. i have heard in the past that the dpm doesn't work below 3000 rpm. Is this true.

OOPS !! I guess this should be in the fuel / carb section, oh well sh%t happens.

Moved ;)

That's the way I understand it. If you hold the enleanment solenoid in your hand, you need to rev the engine past 3000 before you see/feel any movement. So it would be true to say that no dpm before 3000, unless of course the solenoid is sticking open, another story that I'm trying to forget, LOL.

Don't you ever sleep Rocketman? :p

I gave up on the DPM after the first year. Once you start pushing things in the high performance direction, the DPM is much more trouble than it is worth!! I yanked it. It's now in the spare parts drawer.

From what I know of DPm it does not work below the 3000 rpm mark except at start up. It does have an enrichment mode or something of that nature to help with start ups. As for it working at all I'm still confused. I still found myself playing with the carbs a lot even with DPM. I'm glad i don't have it on my 04.

speed is everything,

Last year there were threads on a couple of the forums outlining 3 requirements for the DPM to begin compensating:

1) RPM > 3000

2) Pressure below 1000mBar

3) Temperature above -4°F.

The latest Doo manuals I have are for 2001 and I do not remember seeing these listed though they make sense.

Hillpounder makes a good point with the solenoid. It is designed so that a failure (solenoid open) will leave jetting as rich as possible. Interesting to note that the solenoid constantly cycles open/closed and the rate controls the vacuum application to the carb float bowls. I don't know if the solenoids ever have a "partial" failure where they cycle, but at a reduced rate??? Probably not.

Most (maybe all?) of the DPM systems with the Series 3 engines have not had the ability to enrich the carb jetting at startup. This was on the 99 and older sleds (not sure about '99 600's) and I have heard maybe the electric start models of later sleds. It is easy to tell if the DPM system has this feature because there is an extra solenoid in the DPM rail fed by an air pump.

Hope this helps,

SummitAK

idooski brings up a good point.I myself have had great luck with the dpm on my sleds.he on the other hand did not.one differance between our motors was mine are stock with some external bolt ons,with the exception of the boyesson reeds.is his problem because the dpm uses the engine for the pressure?

Thanks for the reply's. I didn't know that there were any models that it helped at start up, maybe thats another discussion. I have never heard or felt any movement in the selonoid when i put the teather on or pulled up the kill switch on my 01 mxz 800 though.

To the best of my knowledge enrichment was only on the 99 models, the rest of the info is correct. The early DPMs were kinda poor IMO but since theyve switched to the small rail assembly The DPM seems to work just as its supposed to, I took it off my 2000 700, but its staying on my 2003.

I could be wrong about the enrichment thing. it may have been on only 99's or so. I just remember my dealer talking about it. I know DPM is a good idea but on my 02 MX Z 600 Doo did a really poor job calibrating the carbs. I found for my location I really had to fiddle with the carbs to get the sled to run better. Stock the plugs would look really black and occasionally foul. I dropped down to 490 mains and pulled the plastic washer out from under the needle. Big difference. Plugs looked way better and any midrange load up was gone. DPM may have enhanced these changes i dont know.

The '98X Summit had the enrichement circuit and used the aluminum DPM manifold. The manuals for that era show the system for a triple so some of the '98 triples must have had it too. Touring or GT type sleds maybe???

Its been gone from all the sleds I've seen after '99, but we have mostly mountain and performance trail sleds up here.

SummitAK

yes a grand touring 700 I rode,had the enrichment.man I wish i had bought that sled it rocked 700 triple/triple :0: .I am thinking 97 on that sled.

Could someone please instruct me as to how to disconnect the dpm mainfold. I too need to remove it, but am unsure as to which hoses to jump and which to plugg off. Thanks in advance

Could someone please instruct me as to how to disconnect the dpm mainfold. I too need to remove it, but am unsure as to which hoses to jump and which to plugg off. Thanks in advance

I have the same question for a 01'H.M.800----------Proflow