motor ticking under load

[SicRipp83]

hey guys just as the title says. motor runs great, but if you put a big load on it in any geat thier is a distinct ticking coming from the motor. sounds almost like a small exhaust leak, but i checked that. also thought mabey the plug was loose ( happened to me on a sled once) butit wasnt any help would be great thanks

[DnB_racing]

it could be several things...


1:: low octane fuel.did you change your brand of fuel and is it fresh

2::it could be a main bearing, have you been keeping up with the oil changes, next oil change cut open filter to look for any metal particles

3:: it could be one of several things in your valve train, cam chain loose or worn, worn cam chain sliders, bad adjuster, worn out valve springs, bent valves,out of spec valve clearance

4::water pump bearings could be getting worn, oil pump making noise

5::Piston pin is getting worn from poor lubrication,

6:: timing off slightly from a worn cam, or chain

as you can see it can be many things,
but most of them will give some symptoms, check your plug and see what it looks like,
get a good stethoscope and see if you can isolate approximately the noise is coming from
run new high octane fuel
check your valve clearance
do a leak down test
and definitely cut open your oil filter and look for particles
if you lucky enough like me to have access a thermal camera, take some images to try to find a unusual hot spot
Ive got full temp images and 20 minuets after shut down images of all my motors for reference

I personally would do a tear down on any of my motors if I couldn't isolate the problem with all the things Ive mentioned, but that's me, some will run it till its bad enough to easily find, but Ive found there is usually more damage done this way

[SicRipp83]

im going to start with the valve clearence, hasnt been done in awhile. i was told that if the valves were getting way out that it would start hard when hot. always fires. idk also u should know that the piston has about 20hrs on it. quad is a 2007 with an hrc kit, je piston 12:5 i hope i dont need a rebuild the thing runs beatiful besides this also gas has been ****ty latly

[SicRipp83]

checked the valves, all in check but the decompression looked like the clearence was huge can anyone walk me through how to adjust it

[DnB_racing]

Originally posted by SicRipp83
checked the valves, all in check but the decompression looked like the clearence was huge can anyone walk me through how to adjust it the manual has a recommendation of .010 inch for decompressor mech. plus .011 for exhaust...

but I use a compression tester instead,I like to set my starting compression for a lightly modified engine like yours to around 62psi

but I will still check the gap with a feller gauge

then I document both measurements for future troubleshooting

[desratt]

Crappy fuel.