ltr 450 top end rebuild

1bad06ltr450 · #1 (**permalink**) 05-23-2010, 06:15 PM

Hi guys, i just rebuilt the top end on my 06 ltr. Used a JE piston and rings, new gaskets, etc. I got the wheeler together and it started right up. I let it idle for a min or two, then idled it up and down the driveway. It ran fine for maybe 5 min then it just stalled out. I thought maybe it had bad gas since it has been sitting a month and a half. drained all the old gas and added new 93. It would start and stall within a few seconds. It did this a few times and now im getting nothing. It sounds like its out of time. Has alittle lope to it now when i crank it over, It also keeps blurping out of the air box. I checked the timing and it still seems to be right on. The valves are still also in spec. What the heck? Before it would crank real hard, to the piont where i had to put the charger on it, now it just spins over fairly easy when trying to start it. Am i overlooking something here? I cant believe there is something wrong with the piston allready. It only ran for maybe a total of 5 min. it is a 12:5-1 piston but alot of guys are using 93 without a problem. I also checked the plug. Any suggestions?

jfaubus · #2 (**permalink**) 05-23-2010, 08:34 PM

I would check the timing again just to make sure.

1bad06ltr450 · #3 (**permalink**) 05-24-2010, 05:54 AM

I double checked the timing again this am. The Gears are still lined up right where they should be with the T on the flywheel. BUT the cam lobes are suppose to be around 10 o clock and 2 o clock position. The exhaust cam is in the 10 position but the intake cam is in a 5 o clock position. At first i thought the cam chain jumped but the gears are still lined up and im still 15 pins on the chain. The lobes were in the 10 and 2 when i put it together so now what happend?? Did the cam gear spin on the cam? Anyone had this issue? I saw a post similar to this before but i never saw what the outcome was. Im thinking im going to get a new intake cam i guess.

**CQR** · #4 (**permalink**) 05-24-2010, 06:07 AM

Sounds like the cam spun. Pop off the cam caps and see if the head is junk. Usually this happens from over torquing cam and the cam seizing in the journals.

1bad06ltr450 · #5 (**permalink**) 05-24-2010, 07:34 AM

Omg. How would i be able to tell if the head is junk? Look for scoring where the cam rides? My damn torqe wench must not be acurate i guess.

NWI_#73 · #6 (**permalink**) 05-24-2010, 07:52 AM

Did you torque them to 7 ft-lbs?

1bad06ltr450 · #7 (**permalink**) 05-24-2010, 08:00 AM

i thought i did but i was using a older torque wrench so it probably isnt the most acurate. I guess i didnt realize how seriuos it was for them caps to be excact. I never had this issue before. Now i dont know what to do. It only ran for maybe 5 min but the way my luck has ran lately the head will be junk. I allready know i will need a cam. Is there any hope for fixing the head on my own?

Baracudaaa · #8 (**permalink**) 05-24-2010, 09:09 AM

Dont feel bad, there are a bunch of us who did the same thing.

Bad part, get ready to drop about $700 on new cams, head work, and gaskets.

1bad06ltr450 · #9 (**permalink**) 06-16-2010, 06:30 PM

Hey guys, just an update. I bought a new intake cam after my experience with overtightening the cam holders, and spining the gear on the intake cam. The exhaust cam was fine. Installed both cams, and torqued it down. It runs great. I have about 5 hr on it now and seems good to go. Just alittle incuregment for the guys out there with the same issue. You may get away without replacing the head. Allthogh i only ran mine for maybe 4 min idleing when the cam locked up. If you lock it up when your ripping on it, well that may not go so well.

shrimp2 · #10 (**permalink**) 06-19-2010, 01:09 AM

i overturned my cam holders, bought new ones put it all back together and now the thing doesnt start and hardly wont hand turn over. my motor seems to be done /: