New To This 87 LT80.. Lil Help

[rob12]

Well I got a 1/2 complete 87 lt80... I just got it together fired it up and runs excellent!!!

UNTILL

I started it the other day for its daily "look at me" ...

Was just idling and then I hear what sounded like an extra ting ting in there and sounding like a low sounding backfire every once in a while. Its not backfiring however, I felt the exhaust while it was doing this. It would idle and sound fine, then it would drop idle and start with the ting ting... It does not stall out but has what sounds like a penny in the dryer. I'm mainly a 4 stroke guy so the 2 stroke stuff is slightly greek to me.

Any help is appreciated !!!!

[LT80]

I wonder if it's piston slap. How did the piston/bore look when you assembled?
Compression test?
Did you service the clutchs?

[rob12]

The guy I bought it from did most of the motor work. He gave me a list of things he did and I only paid attention to the new crank and bearings part. I'll be getting with him tomorrow to get a full run down.

This is the first one of these beasts I've owned, so checking all the things you listed will be new to me. Have no idea what to look for when talking about clutches.

It takes off great, starts first pull and almost seems like it has too much compression. I can't get it to start off the battery even when on a booster. (turns over too slow)... But 1st pull on the cord and we're off.

Would this be a possible reed issue??? I say that cause of the sudden drop in idle....

Thanks A Bunch for the read and reply!!

[yophilly]

I would remove the flywheel and check the stator plate bolts, it sounds like that loosened up and it's banging around. If the timing is way advanced from that it will be hard to start by the starter.

[LT80]

Not that it couldn't be the stator bolts (good call) but I think his starter is bad.
I'll presume the compression is good considering it starts right up.
Also a good chance the clutchs are fine.

Ok, back to that starter.........It wouldn't be the first LT starter that the starter gear sorta floats around and comes out and hits the crankshaft starting gear and "pings".

[yophilly]

Originally posted by LT80
Not that it couldn't be the stator bolts (good call) but I think his starter is bad.
I'll presume the compression is good considering it starts right up.
Also a good chance the clutchs are fine.

Ok, back to that starter.........It wouldn't be the first LT starter that the starter gear sorta floats around and comes out and hits the crankshaft starting gear and "pings".


I agree , plus it's alot easier to check the starter than it is to pull a flywheel. I think they call that gear a 'bendix'? Maybe that's just on cars.....

[rob12]

I'll check the starter...

Started er up today and let it idle, the sound now sounds like its going with the piston. May take er down to make sure I'm not injuring it more...

Anybody got any good ideas on how to break one of them damn bolts loose from the top of the tank. Got one just spinning in there and it sucks!!!

[LT80]

ACK!!
You have to like pry and turn. If that don't work..
Sometimes you have to cut the plastic around the screw.

[rob12]

Well, fired er up....

No more dropping of idle, BUT the tick is constant and seems to possibly be in the bottom end. It gets faster with the touch of the throttle... Ughhh..

[rob12]

Well decided to tear the top end off n looked around. Rod has a fair share of side to side and a VERY lil bit of up n down play. The up n down is what sounds like the noise. Its so small that it makes me think it can't be it, but on the other hand I've been told any up n down is gonna make some noise. Is it the rod bearing or the wrist pin... Thats the next mystery to be solved. If its on the bottom, do I need a crank??

[LT80]

You need a crank. :(

Weird, it seems that this is "the year of the crank".
Ever so many have gone down this past 6 months.

One year it's~ clean the carb.
Then it's~ service the clutchs
This year it's bottom ends.

I have a good used crankshaft (plus new bearings/seals) here if need be.

[rob12]

Well got the crank on out tonight. Obvious new bearings and seals. Put together good and clean.

BUT... For sure who ever did the job just totally skipped the rod bearing. Everything looks great in there. Have NO IDEA why someone would cut the main corner.

Question: Should I simply buy a rod and bearing set?? My brother works at a full machine shop and would have no problem pressing it out n replacing.

OR... should I just get a crank with it all already there??

LT80... If the latter of the 2 is preferred, what ya looking to get out of your crank?? I only need it as the bearings and seals are brand new.... Feel free to PM me if thats the preferred method.

Thank You ALL for the help in this.

[LT80]

I think I understand the 'cut" thing. The rods have that cut in them for oiling purposes.

If you have the means (and it sounds like you do) get a new rod/bearing. I'm sure he has a press.

I use a Koyo brg at about 10 bucks each. Suzuki brgs are the same thing for 24 bucks or so. They are #6204 bearings. You can get them locally.
Suzuki seals are like 2 bucks or so each and I use nothing but Suzuki seals.
:)

[rob12]

Well, got me another motor. Guy says I can have whatever I need out of it... Bearings and seals in mine are new new new... Gonna swap cranks and move on out!!

[handbuiltxj]

Originally posted by LT80


One year it's~ clean the carb.
Then it's~ service the clutchs
This year it's bottom ends.



Looks like I will leave my LT80s parked this year and hope that next year returns to clean the carb year

[LT80]

LOL :D :D