Power Jet Frustration

Spitfire79 · Post by **Spitfire79** » Thu Mar 01, 2007 1:37 pm

I'm getting really rustrated with the Power jet carbs on my 80 Liquifire.
Had the sled running pretty good in the shop. ( Still need to get chokes set proper- won't lift high enough. Wrong cable I think) Couple squirts of pre-mix in the carbs and would start with 2-3 pulls.
Then I had it outside, tried starting after sitting for a couple hours and it would only cough and sputter. Run for a couple seconds. Seems to flood very quick. Plugs are soaked. Any ideas?
I'm ready to switch to regular Mikuni's. If so, what size should I look for? 36 or 38's?
And what size jets? I figure about 230 to start

Thanks

Jeff

Mr. Deere · Post by **Mr. Deere** » Thu Mar 01, 2007 5:23 pm

Power Jet should have nothing to do with the sled startup. The Power Jet only functions after 3/4 throttle. You propabply have a problem with your idel circuit. BOB

Spitfire79 · Post by **Spitfire79** » Thu Mar 01, 2007 8:46 pm

I've gone through carbs twice. Replace jets, etc.
When I had it running, it bogged unles you fathered the throttle. Running out of solutions. Gues I'll pull them apart again

Bassps70 · Post by **Bassps70** » Thu Mar 01, 2007 9:12 pm

I would check the choke adjustment. Make sure there is 1/8" of slack in the cable with the dash down. Also check the inlet needles and seats. The correct one is 1.5. When it's not starting, is it harder to pull? If it is, the fuel pump could be leaking fuel back into the crankcase. Hope you figure it out.
Mark

grasscutter97 · Post by **grasscutter97** » Fri Mar 02, 2007 12:09 am

Running good in the shop = warmth.
Running good outside = not jetted for cold or your (not correct) choke cable is in a bind when hood shuts and is flooding carbs...or you still have crap in your carbs.

Sidebar---> Had a friend clean his carbs on his 80 Invader 5 times. I know cause he was in my shop. Soaked them overnight every single time. Sled still ran like crap. We checked and re-checked everything. On the last carb re-build we found (not sure how to describe this...), the 'vent tube that is in the carb top 1/2, that pokes down into the bottom bowl..I'm thinking vent tube, or emulsion tube? Anyways, it was plugged solid! Took a small size drill bit and worked it down the tube by hand. Got it opened, soak the top piece overnight again, and sprayed that tube clean with carb cleaner then air. Assembled it and she purrrrrsss!!!!

Moral----> Leave no stone unturned.

Here are 2 carb options that work VERY well: (Don't match one part only, verify exactly what you have, write it down and keep a record of your jetting changes until you get it spot on)

Carb jetting 1:
150 main
95 powers
p-4 needle jet
6-DH4 needle
40 pilot
3.5 ca

or Carb 2:
160 main
95/100 power (mag/pto)
p-4 or p-6 needle jet
6DH4 needle
30 pilot
3.0 ca

Carb 1 is nearly identical to 80-81 PIP carb changes. Carb 2 is from Rich (TITTL).

I run a combination of the 2. (carb 2 with 150 mains and 95 powers = all around performance and decent fuel mileage @ 0-20 deg)

My 80 Liq is jetted for 20 deg and colder. If it hits 30 outside the thing bogs like the carbs haven't been cleaned in 5 yrs.

Bogs are also cause by weak clutch springs, incorrect gearing (i hear that 22/39 gears will help out the off line bog as well), bad clutches (prime + second)

I've got an NOS correct 80-81 Liq choke cable in package if your are going to shop around for one.

(NOS ones had one cable about 1.5" longer than the other. Aftermarkets have both cables same length. Aftermarkets work, just be sure it isn't in a bind and going into 'choke' mode)

Have fun.

Spitfire79 · Post by **Spitfire79** » Sun Mar 04, 2007 12:55 am

Well, I tore the carbs apart one more time.
Let them soak, rinsed, and blew them with air.

I have 150 mains
105/110 power jets, ( mag/pto)
6-DH8 needles,
p-4 needle jets.
30 pilots.
3.5 cut away.

re-set chokes according to manual.
Got it running ( mostly) starts with full choke in 5-6 pulls.
Problem is that when itr warms up, it pops / misses. Thought the timing was out. But I noticed that the carb boots were leaking. ( new boots) I couldn't get exact matchs so went with Invader boots. They are slightly shorter. Is there supposed to be a gasket between boot and intake? The ones I took off had a gasket?
What do otjhers use for boots?

Sorry for the long post. Just getting frustrated with this sled.

Jeff

sledchad · Post by **sledchad** » Thu Mar 08, 2007 12:41 am

I would get the boots from Parts Unlimited, they have the correct ones you need. They might come with a gasket if they dont just get a tube of threebond, clean cylinder mating surface and apply. Let dry for a couple hours before running. Did you check your gass tank?

Spitfire79 · Post by **Spitfire79** » Thu Mar 08, 2007 3:24 pm

Thanks Guys
It runs btter now after going through carbs again. I took the gaskts off, and there seems to be no leak on th arb boots. I did notice that if I'm not careful , the boots seem to flex and allow leakage.
Problem now is after it warms up, 4-8 minutes, it bogs, loses pwer, pops/misses. It seems to run on both cylinders, but not sounding right. If I pull a plug wire and put back on, it picks up again, running better but only for a coyuple minutes. My thought is the coil or CDI ?
Any suggestions? I've got a new coil on my Soitfire. Are they the same? The manual shows how to check CDI/ Coil, but uses the JDM-78 tester. How can I check with an Ohmmeter?

Thanks

Jeff

Liquifire 4/6 · Post by **Liquifire 4/6** » Tue Mar 13, 2007 7:06 pm

Hey Mark...you mentioned that the correct inlet needle valves for the Liquifire (kawasaki version) is a 1.5. I don't curently have a liquifire, but I owned a couple way way back.....and I know both of mine used 1.2 needle/seat assemblies. I did end up replacing them on one of my Liqs with 1.5's because that was all I could find, but I swear it never ran as good as it had with the originals ......I sold the sled without ever finding any 1.2's with the proper threads. Has anybody out there found a supplier for the 1.2's? someone must have them. Did some of the Liquifires come stock with 1.5's?

Mr. Deere · Post by **Mr. Deere** » Thu Mar 15, 2007 4:21 pm

Since we are talking carb problems I have a new one. I will ride around for maybe ten minuets and then it will sputter and almost actually i think it does drop to one cylinder and die. I took the fuel pump apart and found that is was clean so i am confused. If its the CDI I'm going to be rip S***. I think it might be dirty carbs. It just started doing this towards the end of the season. Also noticed a lot of air in the gas Lines. BOB

qwerty · Post by **qwerty** » Thu Mar 15, 2007 9:31 pm

mr deere. it sounds like you have a bad pick up tube. a plugged in tank filter. a plugged pump. these items will varnish/rust up just like the carbs. i would blow in the tank and see if fuel comes out the line. that filter should have a check valve which may be stuck. air in the fuel lines is not uncommon, but you should see a steady dribble flowing into the carbs when you yank on the starter. try this first.

qwerty · Post by **qwerty** » Thu Mar 15, 2007 9:43 pm

i have a feeling that these thigs dont start or idle properly unless the air intake silencer is installed properly. can anyone confirm this

Mr. Deere · Post by **Mr. Deere** » Fri Mar 16, 2007 10:09 am

Yes you need the AIR BOX Installed or else you will LEAN out the sled. Qwerty thanks for the help. I need a new check valve actually. I sometimes blow into the tank to prime the carbs after i empty them. Also When it was running Crappy i pulled the choke on my Mag side and nothing happened. I hope its not a CDI problem. Hold on Now that you mention the dribble. My Pto carb will have gas in the line and my Mag wont have any at all or very little and not enough to make it over the bend in the line. BOB

qwerty · Post by **qwerty** » Sat Mar 17, 2007 3:24 pm

the filter with check valve is available from kimpex for only $4 pn#07-241. use care when prying grommet out of fuel tank so as not to damage it. if it is rotten and needs replacement i know that one from a blizzard 5500 snowmobile is a perfect fit.

Mr. Deere · Post by **Mr. Deere** » Sun Mar 18, 2007 6:13 pm

Thanks. Deere actually still sells the check valve pickup. Im at a loss it did it again today. BOB