Question About A 500 Summit

[Billy Boy]

Have a question about a 97 500 LC Summit I own. I have had the sled since 99 and it has about 5100 klicks on it. It has been a very reliable sled and it is now the kids sled when ever we go riding but (there is always a but) the last couple of times we have had it out in the mountains it is very hard to start after it has been running for a while, it seems to be flooding out? (have checked the plugs and they are very wet). Now I have had several opinions on what could be wrong with the most likely being the floats are sticking or the H.A.C.K. starting to fail to the possibility that the rings are wore out. any ideas or opinions out there on what it could be??? I will be taking the carbs off and cleaning them out (start with the simple first) and see if that will help. Any ideas would be appreciated!!

Billy Boy

 

[J_E_SUMMIT]

What is the compression, also try adding a little oil to the cylenders and then re check the compression. If the compression goes up, then the rings are probably bad.
At that milage, I would also check the needle and seets in the carbs and the adjustment of the float bowls.

Thats all the ideas I got,

Jason E

 

[glengine]

Those are all raelly good points.. I think the first thing to do is check the compression with that kind of milage... It easier and cheaper to fix it now rather than wait till a piston comes apart... I go by a general rule that after about 3000km's i change pistons wether it needs it or not... I call it preventative maintanace..

 

[Murminator]

I find if they are pointed down hill the carbs load up with fuel a flood it....thats what mine seems to do if you burp the throttle to rev it up then hit the kill switch it seems to be fine next time you start

 

[Billy Boy]

Thanks for the info, Iam going to haul it into town and start by checking compression and if its seems to be okay I will take the carbs off and give them a good cleaning. Start with the simple and work my way to the more difficult. I know one of you suggested it would be a good idea to do the rings and pistons which will probably happen this summer if I keep the sled. It is a nice sled for women or young kids to ride and the body is still in excellent shape. Thanks for the info.

Billy Boy

 

[glengine]

The summit 5400's are an awesome young person or newbie sled.. They are light and go alot of places.. They are fun for alot of people.. Great learner sled...

 

[Billy Boy]

I still have a riot driving the 500, it is alot of fun to drive and it goes just about every where the bigger sled will go, you may not be able to be the king of the hill for high marking but being king is overrated!!

Billy Boy

 

[glengine]

You got her buddy.. It's not always about how fast you get there, it s about if you get there...And the 500's are good vlimbers... Just look at how many times it won jackson hole in the stock class,,,, And by as large margin....

 

[TABSTER]

It's not always about the size. Its the fun factor.

 

[glengine]

It's not always about the size. Its the fun factor.

That says it exaxtly!!!! Thats the most important thing that you are having fun!!!

 

[TABSTER]

Thats what I've been telling the wife for years. sled talk that is...... of course lmao

 

[glengine]

HAHAHA....yah I'm sure...LOL...HAHAHA...LOL just bugin...

 

[jay007]

I have heard about the HAC sometimes not compensating enough out in the hills, unfortunetly they are not a cheap unit to replace.

How does it run once you get it started??

 

[Billy Boy]

It runs great when you first start it for the day as long as you don't shut it down you can run for miles. The sled was starting hard after we had ran it for a while then shut it off when we were at Chatter Creek last April. The weather was quite overcast with low cloud, raining at the lodge and snowing very heavy once you started to climb up into the alpine, it was also very warm. The local Doo dealer said that foggy heavy moisture type days will affect the HACK but our last trip to Elkford it was doing the same thing under much cooler and dryer conditions. So I am kind of thinking it may not be the HACK but I am doing the process of elimination by cleaning carbs and checking compression, etc. I am hoping it is not the HACK because it would cost as much as new pistons and rings to replace. The worse scenario would be that the HACK and piston and rings would have to be replaced then the repairs would probably not happen.

Billy Boy

 

[Billy Boy]

Did the compression test on the Summit 500 and the results were 110 psi on the mag side and 110 psi on the pto side. I ran the engine for about 5 or 10 minutes before the compression test so it was warm. Is 110 psi good or bad???

Billy Boy

 

[TABSTER]

You should have done your compression test when it was cold, that way you know what it is with the biggest tolerances. You should be fine around a hundred. But I would at least change the rings if it less than 100.

 

[J_E_SUMMIT]

Do the compression test cold, then redo with a squirt of oil in each cylender to see the change. If there is a huge difference, then the top end needs to be looked at. Also, make sure that the compression is withen 10% from side to side, otherwise it needs a top end rebuild regardless.

 

[glengine]

Did the compression test on the Summit 500 and the results were 110 psi on the mag side and 110 psi on the pto side. I ran the engine for about 5 or 10 minutes before the compression test so it was warm. Is 110 psi good or bad???

Billy Boy

That compression is not bad.. I'm not to sure that it's the hack cause it doesn't really do alot in the starting part of your sled.. Does it go thru spark plugs? Does it have a choke or primer? If choke make sure that there is play in the cable and that one of the plungers isn't stuck open. If it's a primer check all lines that they are in good shape and not crack or leaking.. It sure seems to me to be a carb issue of some sort... Have you gone thru the carbs?

 

[KORE]

You could try tweaking your carbs air screw, or idle adjustment. In know for my 670 it made the diference between hard starts and easy ones. Im able to prime 3 times and pull 1 she fires right up. I dont imagine they are dirty. What are you idling at now??

 

[Billy Boy]

Okay I did the compression test cold, both cylinders registered between 118 - 120 psi. Put a drop of oil in the cylinders and then did the compression test again and it registered between 123 - 125 psi. So I am thinking the compression test was not that bad??? I also took off the carbs took them apart and gave them a good cleaning the floats were a little sticky so I took them out and cleaned the shaft they slide up and down on after that the floats moved quite freely. Also I replaced some of the air lines on the HACK system as they were quite brittle also with the HACK there is a line coming out of the centre of the HACK it goes down between the carbs and there is a foam filter on the end of the line. I gave the filter a good cleaning, in regards to the line with the filter it says in my shop manual that that line should be connected to a tube on the mag side of the motor, I located the tube but it has a cover on it so I am assumming the filter on the end of the line is normal??? Any input would be appreciated!!

Billy Boy