jetting 800 ho

[2006sigouin]

Hi

I want to know if some of you are riding a top gun 800 HO with the jaws pipe and pods at sea level.I am trying to setup the one of my friend but it never run perfect like my 600 HO.We are riding between 700 feet to 2500.

For now is got 470 main and i dont know for pilot but i guess it is stock cause he only change the main from 490 to 470 has ad boivin recommend when he removed the matek for the Jaws.

His engine is bogging in the deep powder and does not want to rev good.The clutch setup is the same than the factory and they where working great.I have inspect the clutch and every thing is good.

Please help me ......i am not felling good when have fun in powder and see my friend waiting for me cause his hawk run like ****!

 

[mnsnowhawk]

How does it run when going on hardpack or trails? It could be clutching if it works good on that. I notice my stock clutching bogs a bit in deep snow, but works great on trails. 600ho I really don't know to much about clutching though.

 

[TLKDPROD]

That Gen1 Jaws Pipe out of the ADB factory on an 800 near sea level won't work too too good that's for sure ! Sounds like he's still too rich but :

1st "must thing to do" is to remove the inner sleeve inside the stigner of the Jaws pipe (where it connects to the silencer), look inside, they tacked a sleeve that looks like a 1/2" long tube that reduces the diameter which brings down the stigner size to around 38mm ID, waaaaaay too small for an 800 near sea level. New Gen2 800 specific is waaay bigger.

2nd ADB will always tell you to jet richer than you need. With this pipe at 2900 feet of elevation around -10C, I ran 430-440s. Your friend might want to try to go down again to 460-450. Carry jets when you ride and do it in the field ! We have the chance of having machines that are super-easy to rejet unlike most of the sleds out there... (though most of the sleds out there do have an automatic compensator and come jetted out of the factory a lot "better") So I'd go down to 460, go for a quick ride & read your plugs, adjust as needed !

3rd thing to do if it's still bogging in the pow, like if it's not pulling its RPM in the pow at all and plugs look great then work on your clutches; take some pin weight off the primary. Playing with clickers is something he can also do in the field, click up if you want more RPM, click down if you're over revving and want less RPM. I'd also suggest to put the Purple Doo secondary spring in the secondary (will allow for quicker backshifts and will hold RPM a lot better). As well gearing, if he has a Trail with 32-56 it's kinda high for stock motor setup in the pow and track transfers a lot of load to the system that's not setup to take as much. Spinning a track in the heavy Qc pow is a lot more load than accelerating down a groomed trail !

Good luck !

 

[2006sigouin]

more info tomorow

I am doing some testing and i will come back to tell you if the 800 came back to life .....

 

[sparky27]

bogging 800 hawk

I have an 800 hawk and went through lots of time and money to make it run good. I did all the jetting tried every possible clutch setup including the p-85, put the 28/56 gears and it still bogged in the powder at higher elevation. One of my later steps was digitron to see exhaust temps (should have been right away). The leaner I jetted the better it got and I mean lean white hot plugs the kind that melt pistons fast but at the same time only 1050 on the pyros. I think I had a dud cdi or the factory has these things set up with the timing too retarded to blow up or make power. I put a 2003 summit cdi, flywheel and pick-up coil with the addition of the altitude compensator and I now have brown plugs and 1250 on the pyros. It finally pulls like an 800 where before it was too embarassing to do a pull with anyone else around.

 

[TLKDPROD]

Going down 5 size on the mains, putting a Purple spring in the secondary (stiffer finish) as well as taking A LOT of weight off of the pins might have worked. Did work not too bad at all for me last year actually.

I agree with you that the fuel mapping/ignition mapping in the stock Hawk MPEM has to be something very weird like the rest of the engine setup (detuned pipe, the thickest base gasket out there, airbox with one 1.5" hole that sucks hot air rising from silencer... way to go ADB !)

Getting your MPEM remapped to something a little more agressive like "hot trail curve" like Rude CAN'T be a bad thing. I run the RKtek curve this season since I have this kit in as well.

 

[RudeAwakening]

my 800 has the new jaws gen 2 800 pipe and can and my mpem has been reprogramed to a more agressive mapping and i am running 520 mains (light dry brown) it runs great!

 

[sparky27]

thick base gasket also thats interesting do you think it is thicker than a skidoo model setup or just thicker than the rktek gasket

 

[TLKDPROD]

thick base gasket also thats interesting do you think it is thicker than a skidoo model setup or just thicker than the rktek gasket

What came out factory on mine was a 0.7mm thick for a 12.0 compression ratio (this compression ratio is according to the owner's manual (!!!)). Can you believe that... (pretty low for those who are not familiar with these numbers) You can get 0.5, 0.6, 0.7 and 0.8 from any Doo dealer. Even 0.4mm from I can't remember who exactly. Cometic maybe or Athena. I'd say if you are to rebuild your engine, throw a 0.5mm at it, DON'T do the 0.7 !!! A guy at Sea Level can run 13.0:1 comp ratio NO PROBLEM, at higher elevation we can run higher comp ratio. They've more than likely chosen this to reduce warranty requests/issues.

Rktek's domes are designed to produce their rated compression ratio with a 0.5mm thick base gasket.

So that's another one of my findings revealed... It is probably the same thing with the 6 hunnert I'm 99 and a half % sure.

NOTE : how do you know what Gasket you have ? Answer : look at the back of your gasket, there is either, 5, 6, 7 or 8 holes punched in the gasket itself in between the 2 back bolt holes. Do I have to explain the rest ?

, Ready, set, wrench !

 

[TLKDPROD]

thick base gasket also thats interesting do you think it is thicker than a skidoo model setup or just thicker than the rktek gasket

I think Doo were using the 0.6 in the 800HOs Summits and probably a "factory shaved down head" to produce a 13.5 to 1 Compression ratio. Hard to say because on every parts Manual out there, all 4 thicknesses are always listed... That is made so if a guy want to go to a race and still be "legal" in the stock class or wants to get the max out of his machine (without a head shave or aftermarket head), he throws the 0.5 . Want a "barber chair" ride for 16 000 miles, with less performance and probably less issues too, throw the 0.8mm.

Basically if you go from 0.7 to 0.5, it's like you're shaving your head 0.2mm (or around 0.008").

 

[sparky27]

its all good thanks for the info