Photos and Video:
https://onedrive.live.com/redir?resid=EF997A0CE0CD14D9!2505&authkey=!AAhWUVtzX99_d1U&ithint=album%2c
This is a RaptorIII from '99, i raced it about half the season and it's been in storage ever since...it ran fine when I put it up.
Now I have it back, and problem is it seems to be bogging upon the clutch engagement, it won't hook up and is overheating the clutch.
I did go through the carb and clean it out, it wasn't really gunked up at all. I did not change the diaphragm, but the fuel bowl inside the tank is always full, so it seems to be pumping fine.
Haven't got a new spark plug yet, this one looks light grey (maybe lean?)
Without any load, when I give a bit of throttle it hesitates and grumbles just above idle, but it will rev freely after that.
But under load, the RPM seems to go just above clutch engagement and hovers there quite a bit, just doesn't break through and hook up. Also by looking at the video, seems like alot of ping/popping going on, maybe detonation?
Initially I though this was just clutch slipping, but now seems like power issue, so re-posting here in Briggs forum...please give some advice!
Part of the storage time the kart was leaned upright against a wall, so i'm not sure if that messed anything up. Looking for suggestions of what could go wrong just sitting unused for so long. Carb is cleaned, fuel and oil are new, spark plug and everything else is OE.
Update:
Some prior suggestions were: sticky valves, or worn spark plug wire.
I've pulled the head to check the valves, both seem tight. The intake doesn't tighten up fully until compression stroke is about halfway up - i believe that is a pressure relief that is designed into the camshaft but I could be wrong there.
I went ahead and sprayed a generous amount of WD-40 down the valve stems.
Even with the valve lifted, they do turn but takes some effort, it's not very slippery...lubing them up seemed to help some - i'm not sure how tight or loose they should be, but I understand that under operation they're supposed to rotate around on their own.
The valve timing seems OK to me by looking at it.
Also located a rough spot on the spark plug wire, photo and video of that too...right where it rubs under the fan cover. It doesn't look like much, but i suppose it doesn't take much for Mr Sparky to escape. I'll try to test with some soapy water spray today, and/or put a couple layers of shrink tubing over it.
Also will try to get some video of startup/idle/RPM ranges.
If you guys can think of anything else please let me know!
Again, all the photos and videos are located here:
https://onedrive.live.com/redir?resid=EF997A0CE0CD14D9!2505&authkey=!AAhWUVtzX99_d1U&ithint=album%2c
https://onedrive.live.com/redir?resid=EF997A0CE0CD14D9!2505&authkey=!AAhWUVtzX99_d1U&ithint=album%2c
This is a RaptorIII from '99, i raced it about half the season and it's been in storage ever since...it ran fine when I put it up.
Now I have it back, and problem is it seems to be bogging upon the clutch engagement, it won't hook up and is overheating the clutch.
I did go through the carb and clean it out, it wasn't really gunked up at all. I did not change the diaphragm, but the fuel bowl inside the tank is always full, so it seems to be pumping fine.
Haven't got a new spark plug yet, this one looks light grey (maybe lean?)
Without any load, when I give a bit of throttle it hesitates and grumbles just above idle, but it will rev freely after that.
But under load, the RPM seems to go just above clutch engagement and hovers there quite a bit, just doesn't break through and hook up. Also by looking at the video, seems like alot of ping/popping going on, maybe detonation?
Initially I though this was just clutch slipping, but now seems like power issue, so re-posting here in Briggs forum...please give some advice!
Part of the storage time the kart was leaned upright against a wall, so i'm not sure if that messed anything up. Looking for suggestions of what could go wrong just sitting unused for so long. Carb is cleaned, fuel and oil are new, spark plug and everything else is OE.
Update:
Some prior suggestions were: sticky valves, or worn spark plug wire.
I've pulled the head to check the valves, both seem tight. The intake doesn't tighten up fully until compression stroke is about halfway up - i believe that is a pressure relief that is designed into the camshaft but I could be wrong there.
I went ahead and sprayed a generous amount of WD-40 down the valve stems.
Even with the valve lifted, they do turn but takes some effort, it's not very slippery...lubing them up seemed to help some - i'm not sure how tight or loose they should be, but I understand that under operation they're supposed to rotate around on their own.
The valve timing seems OK to me by looking at it.
Also located a rough spot on the spark plug wire, photo and video of that too...right where it rubs under the fan cover. It doesn't look like much, but i suppose it doesn't take much for Mr Sparky to escape. I'll try to test with some soapy water spray today, and/or put a couple layers of shrink tubing over it.
Also will try to get some video of startup/idle/RPM ranges.
If you guys can think of anything else please let me know!
Again, all the photos and videos are located here:
https://onedrive.live.com/redir?resid=EF997A0CE0CD14D9!2505&authkey=!AAhWUVtzX99_d1U&ithint=album%2c
Last edited: