Power Jet Frustration

Mr. Deere · Post by **Mr. Deere** » Fri Mar 23, 2007 3:07 pm

I will get an exploded view for you Ken so you can the internals. BOB

Post by **ICCSF 108** » Fri Mar 23, 2007 3:19 pm

Jeff, Talked to Wade he doesn't remember either, Forgot to ask you, did you take off the muffler & shake it to see if anything rattles inside (anything being broke off inside) or feel at the exit to make sure that you have good exhaust flow & the pipe isn't restricted by a mouse nest or other foreign object???

Does any body know, If you unplug the rev limiter do you need to run a jumper wire to get the liquifires to run max RPM without the limiter or does it work by just unplugging them, Unplugging just the 3 wire plug & leaving the single wire plugged in or unplugging all wires????

Kenny

Spitfire79 · Post by **Spitfire79** » Fri Mar 23, 2007 3:23 pm

Kenny, nice to be able to talk with you. Thanks for the help.

As we discussed, does anyone know if you can just unplug the rev limitr or do you need to run some sort of jumper wire?
I've unplugged th single and triple wire from the limiter. Once the sled warms up, it has a hard time getting over 4000, as if the limitr kicks in or runs on one cylinder. Sounds like both fire though.

Ken, I'll try the temp gun like you mentioned

Any help is appreciated.
You guys are awesome. Thanks

Jeff

Post by **ICCSF 108** » Fri Mar 23, 2007 3:27 pm

Jeff, read above

Kenny

Mr. Deere · Post by **Mr. Deere** » Fri Mar 23, 2007 4:51 pm

What you can also try is unplugging the main harness to see if there maybe is a problem. Also Ken my boots have a solid plastic piece that has a gasket up to the cylinder then a rubber piece with a gasket to the carb. BOB

Post by **ICCSF 108** » Fri Mar 23, 2007 5:43 pm

Yup, a heat insulator, like I mentioned earlier, I've never seen them used with a Mikuni carb, maybe this was something that someone found out worked better for some kind of application, (high alt.????) i think you could do away with the plastic block & the gaskets..
Might see what Rich or some of the other guy's think of why it was on there.

Kenny

qwerty · Post by **qwerty** » Fri Mar 23, 2007 6:51 pm

while you guys are digging around down there could you have a look at your clearance between the mag side float bowl and the steering shaft. mine is contacting and i think i may have a problem with incorrect boots or maybe thier installed upside down? thanks in advance.

Liquifire 4/6 · Post by **Liquifire 4/6** » Fri Mar 23, 2007 11:15 pm

Jeff, it sounds like you've tried lots of different things on your Liquifire. I've tried to read all the posts, but I mighta missed some. I don't recall seeing any compression test figures, but I assume you've done that and found it to be ok. Regarding the speed limiter, it's been a long time since I've owned a Liquifire, but if I remember correctly, just unplugging all the wires from it would bypass it entirely with no need to run a jumper wire. I know that's what I had to do on my Snowfire this winter and it works fine that way and I see no reason why the Liquifire would be any different. Clutching is very critical on a Liquifire....as soon as any excessive play develops in the primary clutch bushings, flyweights or buttons, you get real bad bogging problems. The belt deflection is also very important...if it's at all loose, they'll barely pull themselves. But, it sounds like your problem is there, even before clutch engagement. Way back when, one of my Liqs did act exactly the way you describe. It was down for half the winter because it had me completely stumped. I was getting a decent compression reading, there was no evidence of crank seal leakage, I had swapped absolutely every ignition component from my other good running Liq...and it still behaved the same way. Swapping the carbs and fuel pump made no difference either.Finally, I completely tore the engine down and at first glance, I could see nothing wrong with it. But upon closer inspection, I discovered a hairline crack that was almost unnoticable in the skirt of the mag side piston. Replacing it resolved the problem....I guess the crack was hampering the proper transfer of fuel from the crankase to the top end. Now this was the problem with mine and I'm not saying it is necessarily the same problem with yours, but the symptoms do sound similar....so I wouldn't rule it out. Another prob that my Liqs had was exhaust gases coming back into the engine bay thru the hole in the belly pan around the exhaust outlet...resulting in warm less dense & oxygen deprived air reaching the airbox...this seemed to be a problem more in warm weather (or sometimes in very fluffy snow conditions). This prob was only an issue when the sled was sitting and idling...once it was in motion, the exhaust gases went where they were supposed to, but it would often result in a bog at take off. I solved that problem by modifying an exhaust seal from an older Ski Doo model and mounting it between the exhaust downpipe and the belly pan. Ok, one more Liquifire tip for all you younger fellows that don't have a ton of miles on one yet (everybody else will know this)......beware of the lower coolant hose that snakes it's way from the water pump around the lower part of the steering post and over to the heat exchanger. It is in almost constant contact with the post and it does wear out. Keep an eye on it....it cost me an engine. Yeah, I know, I shoulda been watching the temp gauge.

Pete

Danzig · Post by **Danzig** » Sat Mar 24, 2007 12:54 am

I too have a 1980 Liquifire, I have not had alot of time on it yet, but it acts the way you are have explained your problems almost perfectly. I personally think the ambient temperature is playing the games with me. CDI was changed out, carbs cleaned, air box installed however I do not have the snorkle tube yet for the air box. 2 days ago I just got her fired up after sitting all winter, it took me about 30 minutes to get her running, kept soaking plugs, backfiring out the exhaust then it would pull over real hard, plugs then pulled cleaned and installed and finally it would run about 5 seconds and die. After enough times of these 5 second runs, the motor got a little heat built up in her and she fired off and ran. Ran not to bad either but the weather was about 64 degrees too. Sled hasnt been started since October of last year.

This thread is reminding me of my problem......that being the X8.

I feel your pain.

Mr. Deere · Post by **Mr. Deere** » Sat Mar 24, 2007 7:09 pm

Ok Ken i guess you were right. Querty my carb is a pain in the but to put in next to the shaft but it doesnt rub its close but i think my airbox might. BOB

Spitfire79 · Post by **Spitfire79** » Sat Mar 24, 2007 11:46 pm

You guys have all been a huge help.

As I discussed with Kenny, I think my problem is something simple. Just need to figure it out.

So... let me think. Carbs all cleaned ( several times) and set.
Coil and CDI replaced.
Compression good ( 120 & 123)
New plugs B9ES
New plug boots ( plastic- ICCSF suggested Briggs/Stratton ends )
Carb boots replaced, air box on.
Chokes set ( 1/8" play)
Will start in 5-7 pulls usually
Idles at approx 3600 rpm

After a couple minutes warm-up it will run good- some bog but nothing major.
I can drive around crack it open runs fine for 10-15 minutes.
After this it will still idle but wont make power. If I lift the track off the ground, sometimes it will turn it.
Then engine sounds slightly different as well. Doesn't seem to have the same tone to it.

Qwerty...... My mag side sits very close as well. I did notice that if I didnt push the carb completely into the boot, that it would hit the shaft.

Danzig, you didn't send your gremlins up to Canada , eh?

Jeff

kenv56 · Post by **kenv56** » Sun Mar 25, 2007 12:43 am

Do you think it could be excess cylinder to piston clearance?

I had experience with an engine, had good compression, 120 on both sides, started up fine, but bogged so bad at the end of its life that it couldn't even drive anymore. took the exhaust and y-pipe off, and looked at the pistons, found the PTO side to have a piston skirt completely gone. couldn't even tell on the heads that something was wrong but the skirt was gone on the exhaust side of the piston. I found this very interesting since it still had good compression.
So we had another engine that we put in, same type, had the same type of thing, bogs really bad on take off but once moving it was okay. So we went ahead and rebuilt the original engine, and after that ran great. Had nothing to do with carbs. My theory on that was with too much clearance the engine wasn't able to make a good enough vacuum to draw the fuel in. What do you guys think about this theory? Its the only thing that i can come up with.

Mr. Deere · Post by **Mr. Deere** » Sun Mar 25, 2007 7:52 pm

I am still betting on the seals. BOB