Suz. LT80 Hard to turn engine

[surveywaters]

I have an '87 Suzuki LT80. It was running great. Kids parked it before supper, afterwards I couldn't start it. The engine is really hard to turn with the pull rope. It has oil in the tank and the oil pump is working. what could it be?:confused:

[fearlessfred]

hydrostatic lock the fuel petcock/fuel pump goes out and fills the crankcase with fuel pull the spark plug and crank it over and see if fuel blows out

[surveywaters]

what would cause the crank to fill up? would the needle valve not prevent this? I believe this is my problem. Once I figure out how to empty the crank I need to figure out how to prevent it from happening again. My petcock is bad so I run it on prime and when it isn't running I have an inline shutoff I use.

[fearlessfred]

i think what happens is the rubber diafram in the fuel pump/petcock gets cracked and the fuel leaks past into the the vaccum line that operates the pump therfore bypassing the needle and seat u could prob. ck. that by pulling the vaccum line and seeing if fuel runs out i have allway just changed them out when they start doing that and that fixs it the pump/petcock assem. cost 75.00 to 100.00 depending were u by from if the vaccum line does have fuel running out of it maybe u could plug it off and run on prime to prove that is the problem u really have to turn the motor over a lot with out the sparkplug to get all the gas out of the crankcase

[surveywaters]

Thank you!
I have been rackin my brain trying to figure out how that gas got in there. I have been running on prime for over a year now but I guess it finally started doing this drain through the vacuum line. Out of all the possibilities, that makes the most since. I ordered a new reed, rings and a top end gasket set. So I'll pull the head to drain the crank, reassemble and just plug off that vacuum. I have seen an aftermarket petcock that just has the traditional on/off/res , I think I may replace the OEM with it. I really do appreciate you answering this post. I was ready for a rebuild, lol.

[fearlessfred]

if u are doing a fresh top end make sure u ck the end gap on the rings with them in the cylinder i think that gap is a min.of .oo6 the last three topend i have done needed to have the end gap widened [not enough clearance] maybe thats just how they come from suzuki if u dont do it u probaly will end up tearing it apart again good luck

[surveywaters]

if the end gap is short what do you do? seems like stretching it out wouldn't do a thing.

Also, I have torn the engine out and removed the head. The reeds are cracked and chipped and the lower ring was seized in the piston (not protruding at all). I emptied the crank of fuel and I can feel grit in it. Should I just rinse it with kerosene or do I need to open the crankcase up and clean it? I don't have all the specialty tools needed for that.

[fearlessfred]

that grit thing doesnt sound to good i have used diesel to clean out the bottom end before back to the ring thing what i was talking about was the minimum ciearance on the rings u put the ring in the cylinder use the piston turned upside down to push the rings a few inchs down [but not to far were the ring is into the exaust port] the piston is used just to square up the rings then measure the butt gap with feeler gauges i think the minimum gap is .006 u need to double check that no. in a repair manual the reason for doing this is because if the gap is to tight the rings will expand as they heat up and the gap will come together and not have any room to grow. that causes the ring to be out of round and not seal to the cylinder. then the motor will not start for lack of compression this should be done on all rebuilds. the clearance is different depending on the size bore my reason for telling u this is the last three lt80 rebuilds the gap was to small and i to file down the end gap to get proper clearance. afriend of mine decided not to do this and the bike would not start after the first heat cycle

[surveywaters]

thanks for the clarification. I have the Suzuki shop maual and it has a maximum tolerance but no minimum. 0.006 sounds good, surely it won't expand more than that and it's well under the max. The grit seems to be loose carbon, not deadly sand. The exhaust was filled with gas and I believe it may have washed backwards bringing deposits back into the engine.

[fearlessfred]

right on ,gota keep the kids bikes running with 4 boys i have had to keep those 80s running for the last 14 years

[surveywaters]

Any tips on getting the clutch off with out the $70 tool?
I pulled the front driven gear off and the grease had solidified, I don't think it has hit the high band since I bought it 6 years ago, can't wait to get her back together now!!!

[fearlessfred]

sorry ,never had to get into that before

[surveywaters]

It is recomended as regular maintenance and I see why. The grease in there literally solidified. If you haven't done this, you may want to consider it. It was not that difficult to get to and with the right tool could probably be done in an easy afternoon.

[fearlessfred]

dont have to worry about it my youngest twin 10 year olds have moved up to bigger quads now they can ride in the big sand dunes with there fat old man its so cool riding with your kids and seeing the learn to haul *** thanks for the info just the same fred