Guests - If You want access to member only forums on HSO. You will gain access only when you sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
wall_guy_101

Mid 80's 25hp LS....Won't stay running

20 posts in this topic

Alright,

Last year my motor was getting progressively harder to start. Now it won't start at all. I've put in a new carb kit,jets have spark but my plugs seem excessively wet. Flooding out? Perhaps float adjustment?....need recommendations cause it's driving me nuts. It will spit and sputter but just can't get it to keep on keeping on.

Thanks.

Share this post


Link to post
Share on other sites

fuel filter, carbs rebuild, replace fuel lines, etc, it sounds fuel related

Share this post


Link to post
Share on other sites

Sounds like it is time to replace the plugs. Then, when you get it going, do a hard shot of sea-foam through the carb throat, get it in there until the motor dies, then put a bit more in, let it sit for a spell (20 minutes minimum) then take it out and run it wide open until the whole system is cleared out.

To me, it sounds like plugs are fouling out, and the system just needs a good decarbonizing.

Steve

Share this post


Link to post
Share on other sites

Wow, what happend to the search function on this board? I can't do a specific search... so... I tried to search a thread I had going and all the steps I did. Mine was remarkably similar to yours, and I think it would help you out, if anybody can find it.

BoxMN was posted, and it was about in April of this year. Good luck finding it... maybe my problem finding it is related to my IE8 issues with this board. I jsut wanted to post the link to my thread.

Share this post


Link to post
Share on other sites

Old gas is definitely not the problem....made sure to empty and clean tank and also ran non-oxygenated 91oct. fuel. The plugs were brand new a week ago so i have to eliminate that as an issue. I have to think it may be a stuck needle?? Perhaps it's not seating all the way letting to much fuel in. Will keep you updated and thanks for the responses!!

Share this post


Link to post
Share on other sites

something cheap you can try: Replace the plug wires. Over time, the plug wires will eventually lose their capability to carry a current due to build-up of of resistance in the wire. Shouldn't cost more than a few $$ and is good preventative maintenance. Being a mid 80's motor, it certainly couldn't hurt...

tough thing is that it's like shooting in the dark.

What brand motor?

Share this post


Link to post
Share on other sites

Yep, thanks Black Bay, that is it.

You will see the mistakes I made and the little things to check. All in all, everything was easy on my motor, just make sure to check every detail to make sure you did things right.

Now it is "running like a Mercury" wink

Share this post


Link to post
Share on other sites

Thanks so far for the responses!

I tore apart the carb today (again) with no better results. It looks like i'm getting a very good solid spark. Im beginning to believe it may be an electrical issue such as timing. It is a mercury by the way. The plugs are still wet looking even though I turned the needle way down. Still spits and sputters but can't get it to stay going. Will try the new wires but my mind is telling me it's something different. Still not sure what though. Another thing i'm encountering is after so many pulls today i'm getting really black oil dripping off of the bottom of the motor.......What next?? Perhaps it's the crank seal??....thanks again.

Share this post


Link to post
Share on other sites

Sounds to me that you have the opposite of BoxMN's problem - too much fuel..

Which would point me back to the carburetor if you have good spark. If your float is made of a sponge-like material, sometimes they will get soaked with fuel, and when that happens, they won't float up and shut the fuel supply off like they are supposed to...

Share this post


Link to post
Share on other sites

Afraid thats not it....its the hard plastic bladder style....

Share this post


Link to post
Share on other sites

if you take the float out and shake it does it have fuel in it? Have you checked the oil level to make sure that it is not making oil by pushing gas into the crankcase? We have this on some smaller equipment when it sits with the valve on, it seeps into the crack case then wont start. Just a thought.

Share this post


Link to post
Share on other sites

Still think your getting too much fuel some way - needle valve not closing all the way or float not adjusted right, or something on that order.

Does the motor have good compression?

Share this post


Link to post
Share on other sites

Not familiar with that motor but if it has a fuel pump maybe the diaphragm is shot. Is there a primer bulb? If so does it stay hard.

Share this post


Link to post
Share on other sites

did you check the compression with a tester you need at least 85 psi or its not going to want to stay running.

Share this post


Link to post
Share on other sites

Euro has a great suggestion in the fuel pump. If the diaphram is shot, it will pump gas directly into the crankcase.

Share this post


Link to post
Share on other sites

Again, thanks for the replys.

The bulb is staying hard so i'm not tending towards that idea. I'm now thinking towards the crankshaft seal itself. Will check compression tomorrow. Thanks again

Share this post


Link to post
Share on other sites

Hey gents,

After almost a total tear down of the motor i seem to have found the problem(s). #1 Found a slight tear in the vacumm line thatruns from the top of the head around to the intake port. #2 My fuel line bracket was tweaked not allowing it to stay forward enough to start while in the neutral position. Seems to run like a honda now. Thanks again for the responses.

Share this post


Link to post
Share on other sites

Hey gents,

Seems to run like a honda now. Thanks again for the responses.

You mean it is now running like a Merc wink hehe, my "real" boats have Mercs...

Glad you found it! Have fun smile

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0



  • Posts



    • BEFORE BEGINNING

      Before you begin, make sure you have a good strong battery and make sure it's charged up. If you have a bad or weak battery, you may want to replace it because if it doesn't crank good and strong, you are likely to get a low, inaccurate reading. Make sure your engine is warmed up to operating temperature(if possible). About 10 minutes of riding should do.

      First, take out the spark plug and thread in the adapter for the compression tester. Make sure you have the correct size adapter for your particular ATV. Slide your kill switch to the "off" position. Some ATVs won't crank over with the kill switch in the "off" position, so if yours is like this, then you will need to either unhook your ignition coil or ground the end of the spark plug wire to a good ground. You can use a jumper wire with alligator clips on each end to ground it. Next, make sure the throttle is in the wide open position. You can either hold the throttle lever with your thumb or you may be able to tape it or use a zip tie to fasten it to your handlebars to hold it in the wide open position. If you don't have the throttle in the wide open position, you will probably get too low of a reading. Also, if you are testing a newly rebuilt engine, the engine needs to have been run for, at least, 30 or 40 minutes or you will probably get too low of a reading.

      NOTE: Before you begin with the actual test, make sure the threaded adapter is screwed in good and isn't leaking any air out around it.

      ACTUAL TESTING

      With the throttle in the wide open position, push the start button and crank the engine over until the hand on the gauge stops moving. Each time the engine turns over the hand should raise a little more until it reaches the maximum compression of the engine. When it stops, that is your compression reading. This usually takes no more than 10 seconds. Try to avoid cranking an engine for more than 10 seconds at a time as this is hard on the starter and the battery. Now, push the relief valve on your compression gauge and that will reset the hand back to zero. It's a good ideal to repeat the test a couple or three times to make sure you get an accurate reading. On kick start models, it will be the same procedure, but obviously you will be kicking it over instead of using a start button. Worn piston rings and cylinder walls will increase the number of strokes it takes to reach the maximum reading. If you're kicking, it could possibly take as many as 10-20 kicks to get the highest reading.

      THE READING

      You will need to check your repair manual for your particular model for the correct compression specifications. See note below. Usually, an engine will run OK if it has at least 100 PSI of compression. Most engines will have somewhere between 100-250 and some as high as 300 PSI, depending on the engine. Sometimes they will run with under 100 PSI, but usually not very well. If you get a low reading, you can do a "wet test" to try to help determine the problem.

      If your reading is too high, then you probably have carbon built up on your piston and combustion chamber.

      NOTE: You may get a low reading on some engines because some engines have a decompressor assembly built into the camshaft. Check the service manual for your quad to see whether or not your quad has a decompressor assembly built into the cam.

      WET TEST

      If you got a low reading, pour about 1-2 teaspoons of clean motor oil down into the cylinder through the spark plug hole and do the compression test again. If your reading increases, then your rings or cylinder walls are probably worn. If your reading doesn't increase, then it's probably your valves. You could have a bent valve, you may have leaky valve seats, or your valve clearance may not be adjusted properly. Also, low compression can be caused by a blown head gasket.

      CAUSES OF LOW COMPRESSION

      *Worn piston rings or worn or damaged cylinder walls
      *Leaking valves
      *Valve clearance not properly set
      *Blown head gasket

      CAUSE OF HIGH COMPRESSION (stock engines)

      *Carbon buildup in combustion chamber and on piston

      NOTE: Compression testing is a good way to keep track or "gauge" the wear in your engine. When you first get your ATV or when you rebuild the engine in your ATV, you can do a compression test and then later on, you can do them periodically. This will help you determine the wear in your engine each time you do a compression test and will guide you in knowing when your engine needs rebuilding.

      This is about all I can think of. I hope I didn't leave anything out and I hope this helps everyone with their compression tests.
    • As dumb as this sounds how is this done?
    • Try a compression check. And make sure the choke is opening all the way.
    • They are not the best out their but for the price and your average person not too bad I guess, Its going to send lead to where its pointed. This is probably what is going to happen he is going to buy a package shoot it for awhile then start upgrading everything to how he wants it and it is going to end up costing way more than if he just built one himself how he wants it.  
    • Hello, well I convinced my brother in-law to pick up my buddies old 1980 185 although pretty sure he said it was bored out to a 200? Here is the deal it's been sitting for a solid 8 years. I know it ran fine before. Not the delema-----   It starts right up (he bought a new carb odd amazon) although it sounds like a jet with high rpms. Looked at the throttle cable that's fine. Floats are fine. So he plugged this hole in the air filter and got it to idle down although when he hit the gas wouldn't get any power. Read a few things online and they tell you to just bypass the filter box and all that so back to amazon we went to get one of those filters that mount right up to the carb and it's still the same issue..   I just haven't seen anything like this? Do you guys have any thoughts or tricks that we/he could try?! Thanks in advance
    • Hi Everyone,  I'm looking into buying my first true fish finder and I'm a little perplex with the mapping card situation.  I'm looking at Humminbird Helix 5's and 7's.  I'm drawn to the autochart feature.  From my understanding, you can record 8 hours of charting onto the internal storage, but, is there any native mapping included on the unit or do I absolutely have to get some sort of mapping chip, zerolines or lake master, or navionics?  Can I store data on a blank SD card?  I've been researching this a lot and haven't found any conclusive answers. Thanks everyone!
    • Saul Good, Man.....  LOL 
    •   When do the not so rare Highjack birds show up?  Oh ah. 
  • Our Sponsors