80 Liquifire

kenv56 · Post by **kenv56** » Tue Dec 19, 2006 3:54 pm

I never checked the impulse line. I could check it but I really dont think so since I put a brand pump on it this summer.

The idle is around 2800 - 3000 and when cold there is no bog when takeing off. I just goes and runs like a champ.

Mabey I shouldnt say when the engine is cold, but more like before it starts doing the bog thing. Which can be 5-7 miles.

I also put gasline antifreeze in and made no difference.

Mr. Deere · Post by **Mr. Deere** » Tue Dec 19, 2006 5:28 pm

WOW YOU CAN START IT BY HAND HOW I CNT TURN IT THAT FAST. AND YOUR EVEN USING 93 Octaine VERY HARD STUFF TO IGNITE.. BOB

kenv56 · Post by **kenv56** » Tue Dec 19, 2006 9:32 pm

I would not be starting by spinning the clutch. Its very dangerous. I only did it as a last resort to start my sled, and that was when it was warm.

Mr. Deere · Post by **Mr. Deere** » Tue Dec 19, 2006 10:18 pm

BY HAND OR BY CORD AROUND CLUTCH MY NEIGHBOR STARTS HIS DEERE BY THE CLUTCH THOUGH ITS AN OLD TRACTOR. BOB

kenv56 · Post by **kenv56** » Tue Dec 19, 2006 11:13 pm

Yes thats with my bare hands
But ya any ideas on my problem?
I have a spare CDI that I want to try. I think it might be losing spark under load what do you think?

Rodimus Prime · Post by **Rodimus Prime** » Wed Dec 20, 2006 2:03 am

under general i post the schematic of cdi they either work or they dont.

mag side is soaked way to rich but pto side is dry ... sounds like the same jetting problem .. take it to limit should have posted the correction to jets...

both carb mains should not be the same mag side is usually 1 under the pto side. ie if main is 210 on pto main on mag should be 200 .

so if both your mains are same lower mag by one size...

if your carbs are not the same and have the higher jet on mag your carbs are mixed up .

kenv56 · Post by **kenv56** » Fri Dec 22, 2006 1:13 pm

Which injection pump lines go where on this engine? Thinkin that if one cylinder is getting extra oil that might foul sparkplugs.

kenv56 · Post by **kenv56** » Sun Dec 24, 2006 2:10 am

Okay the oil pump lines were right, and changeing the CDI made no difference at all. This is really confusing me.

cyclone crazy · Post by **cyclone crazy** » Sun Dec 24, 2006 8:32 pm

I had a Liquifire that did the same thing. The problem was finally eliminated after replacing the coil. Must have had a crack in the case or something that was affected by heat.

kenv56 · Post by **kenv56** » Mon Dec 25, 2006 6:24 pm

well i changed the muffler with a different one and it still does the same thing. So i put in brand new plugs and set the gap to .025" and still no difference.

grasscutter97 · Post by **grasscutter97** » Mon Dec 25, 2006 9:02 pm

As I read all the posts, it seems that we have a heat/warm-up related problem. (which points to fuel/carbs) You said you pressure tested the engine? Do a compression test cold. Then run the sled until the problem develops, then do a 2nd compression test. Report back on the results.

I don't believe you will find much difference, but it is one of the 3 basics that needs to be covered (fuel, compression, spark).

The spark is a HOT, blue spark right? And is the same for both cylinders?

Impluse line is tight at the engine and at the pump?

REMEMBER, when an engine is cold, it functions great with carbs set a little rich. A warm engine does not function well with carbs set rich. Not to beat a dead horse, but you completely dismantled EVERY jet, screw, etc in both carbs? New mikuni needle / seat? Floats are set correctly? It only takes one thing in those carbs to be off, even a little bit, and you will not perform.

I personally run (1980 LF) 150 mains, 100 powers, 3.5 cutaway, 40 pilot, 159 P-4 needle carrier, 6DH-4 needle. (Per Take it to the limits suggestions). Compression is fair at 125 both sides. Fantastic performance, cold to hot. No bog at any time.

Solution # 2 (long shot) is that your head gaskets are not sealing well when the engine is warm. I have found many liquifires that have been overtorqued at the heads. It's not too difficult to correct. (get a set of head gaskets, check the flatness of the heads, etc.) You don't need to get new cylinders or heads if you find yours to be warped or if there is some rocking around the head bolts, you can have a machine shop take care of it for a FRACTION of the cost of new cylinders.

kenv56 · Post by **kenv56** » Tue Dec 26, 2006 8:32 pm

Well today I replaced the main jet washer, i lost mine and just used a steel one, after putting in a brass one i havent had the problem yet and I went for a long time.
After riding I pulled the plugs and the PTO side is very light and the MAG side looks good. I find this very strange as the PTO side was always the good side and I never touched it. I moved the needle jet clip for more fuel and it didnt do much other then cause a bit of a midrange bog.

Rodimus Prime · Post by **Rodimus Prime** » Wed Dec 27, 2006 2:00 am

makes sense if washer for main is bad never thought of that..

grasscutter97 · Post by **grasscutter97** » Thu Dec 28, 2006 12:20 am

I have at least 10+yrs restoring deeres, and I have never heard of "the main jet washer". HUH?

Are you talking about something else?

kenv56 · Post by **kenv56** » Thu Dec 28, 2006 2:40 am

Probably not the right term but I posted a picture that should help