1995 Suzuki LT-300 King Quad head pipe cherry red

[Guest spamble11]

hi

some kid wrecked my LT-300 into a pond.......upside down. don't ask. anyway, i think i have everything back to normal except, when the quad idles the exhaust pipe get cherry red, pretty quickly. i assume it to be a mixture problem. it starts and runs fine. any thoughts? if it is mixture, how do I adjust it?

one thing I should tell you is that a friend took off a cable screw from the bottom of the mikuni to let water out (which was wrong). anyway, i have put that back in the carb but, don't know what that is or whether that needs to be adjusted too. (it's a black phillips head screw that has a cable that goes to the bottom of the carb).

help me, please.

tx

Edited July 24, 2010 by spamble11

[DirtDemon]

I think the best place to start is take the carb off, take it completely apart and clean everything. The pilot mix screw is usually on the bottom of the carb just in front of the float bowl. Also, if you haven't done it already, the gas that was in it when it was submerged needs to be thrown out and clean the fuel tank out. I would also run some water through the fuel lines and petcock. The cable you are talking about is the idle adjustment I think.

[Guest spamble11]

tx DirtDemon. I removed all of the fuel and cleaned everything with drygas. i think you are right about the idle adjustement. i found an exploded view of the carb and it shows as an adjuster assembly. i'll try removing the pilot mix screw. I assume this is the fuel/air adjustment? if so, i'll try to richen it up until the pipe is't so toasty. any idea of a range for adjusting that thing?

tx again.

[DirtDemon]

On most machines the setting is between 1 1/2 and 2 1/2 turns out. This only affects the air fuel mix on the pilot circuit, which controls throttle positions from idle to about 1/4 throttle.

[Guest spamble11]

do you think that could cause the red pipe? should this be adjusted while idling?

it does occur at idle and pretty quickly. i would like to avoid taking it off again but, i may have to. i'll also hit it with carb cleaner, for what it is worth.

tx so much for your help. i'm better at breaking them than fixing them.

[Stoopidbot1]

You are in good hands with DD

[superswire]

Clean carb, clean petcock, change oil, make sure the muffler isnt clogged

[Guest spamble11]

i changed all of the fluids and I don't think the muffler is clogged. some watter came out at first but, that's all. I have stood the wheeler almost straight up and down using the winch and ran it for a long time so the muffler should be empty. plus, it runs well so I don't think it's obstructed and the way it heats up, any water in there should have evaporated. i may have to break down the carb as demon suggested. i didn't completely tear it down the first time. maybe I can get away with some carb cleaner and mixture adjustment. although, I don't want to touch the mix as it ran well beforehand and that really shouldn't have moved in the "incident".

[DirtDemon]

If you didn't take the carb all the way apart, it would be best to do so. You want to make sure there is absolutely no gummed fuel or any other debris clogging any passages of any sort. Since it sounds like the machine was pretty well submerged, there is a good chance that there is some foreign debris floating around in there. Spraying carb cleaner in it won't cut it, you need to take it off and COMPLETELY disassemble it. Make sure no passage is over looked. Take the pilot screw all the way out and blow compressed air through the curcuit. You can use compressed air in other spots, like the float bowl vent tube to make sure there are no blockages. You are correct about the pilot adjustment, if there were no problems before, and you never messed with it, then the problem is elsewhere. Most likely inside your carb.

[Guest spamble11]

Ok fellas, took carb out and apart, cleaning it with Castle's Shop Solve. Put it back in, adjusted idle, runs like a top....... wait for it...............and yeah, the head pipe STILL turn cherry red at idle.

Should I try the air/fuel mixture adj? is it possible there is something in the muffler? I don't see how, it runs great, just heats up. Scratching my head now.

I'm dumping the oil again, it's looking grey and sludgy. must be some water in there that I didn't get with the first oil change.

any ideas?

tx for all of your help

[DirtDemon]

The condition of your oil, could be causing your machine to run hot, if there is enough water in there to make the oil look like you described, then the viscosity of the oil will have been severely reduced. This ofcours will increase friction, which turns into heat. I would start by making sure the crankcase is clean and dry. If the problem persists after the oil issue is fixed, I would probably say the following.

I guess it would be a good idea to ask if the machine is completely stock with the airbox and lid unaltered? If there have been any alterations to the machine, a jetting change may be in order. If the muffler is flowing well, seems unobstructed and is not excessively loud, then I would say it is ok. Also, I assume that you never noticed the glowing pipe before the pond incident, do you know for sure that it never did that before? Some machines do get a slight glow on the head pipe that you can usually only see in the dark or really dim lighting, this is normal. Also, since the machine is air cooled, it will tend to run hotter if it is not moving, since there is less airflow running over the engine to help dissipate the heat, you are relying completely on the fan (if you have one) to move air around the motor. Have you confirmed wheather or not the cooling fan is still working? Does your machine have a cooling fan? It was an option on those machines. If it was ruined in the incident, this could be the cause of your problem. Just to err on the side of caution, I would try adjusting the pilot screw just to make sure. Turn the pilot screw inward until the machine starts to run poorly. Then start backing the screw out until the idle reaches its highest point, if needed adjust the idle back down. This should give you a proper air/fuel mix on the pilot circuit. Also, look at the plug, the color of the insulator is a good indicator for judging the condition of your jetting conditions. Good luck, I hope you get this figured out soon.

Edited August 24, 2010 by DirtDemon

[Guest spamble11]

DD,

Thanks again for the help. I agree about the oil, it certainly isn't doing what it is supposed to if it is grey. i'm going to change that, at least once, before I do anything else. What do you mean by the crankcase clean and dry?

The bike is stock, no alterations at all. Muffler flows well and bike runs great, just hot. So I agree, I don't think the muffler is a culprit. Besides, anything in there would have evaporated by now and it's not like the thing was buried in mud, just water. The pipe never glowed before this and I have run it inside the garage so I would have seen it.... i think. Also, it only take like 3 min of running to get it cherry red, there is definitely something up with the bike. There is no cooling fan and it is air cooled but it does have the oil cooler and an indicator light (last I knew it worked) for when the oil temp gets too high. So far, the light has not come on.

I'll change the oil (flush the cooler too) and adjust the pilot screw and see what happens.

If anyone out there has an infrared thermometer and can tell me the approx temp of their head pipe after running at idle for 1, 2 or 3 minutes, that would be great!

tx again.................. the saga continues.

[DirtDemon]

By clean and dry, I mean no water in it for the oil to mix with. You may want to let it sit and air out for a while after draining the oil, let every thing get a chance to pool up and get out the hole. Maybe it wouldn't hurt to blow some compressed air in the hole with the drain plug out to help. Good luck.