RE: RPMs

[broski]

RE: RPMs



I have a john deere 325 18 H.P. Garden Lawn Tractor. In the winter time with the snow blower attachment, the RPMs stay at the max with no problem.

In the spring and summer when the mower deck is on after mowing for 10, 20 or 30 minutes the RPMs just drop to about half on it's own. The throttle lever is at the max and stays in that postion. Sometimes if you sit there for a few minutes, the RPMs come back to Max. Sometimes NOT.

I am going crazy, I don't know what is going on.

Anyone experience the same problem.

I maintain this tractor regularly, and am flabbergasted as to this problem.

Thanks,



Broski............

 

[jenkinsph]

Re: RPMs

I would check the compression when engine is warmed up. Easy to do and could determine the engines condition quickly. Once the engine is warmed up you may not have enough compression to develop the hp you need.

I would also check the fuel system for blockages, the motor could be starved for fuel and with the added load of the mower deck it can't keep up.

Last I would check the ignition advance to make sure it is moving freely. This is more of a long shot, but is easy to check.


I am assuming you have replaced the plugs and filters already.



Steve

 

[broski]

Re: RPMs

Thank you Steve. Plugs and other items are replaced regularly.

The thing that drives me crazy is, in the winter with the snow blower on everything works normal.
This thing only starts happening in the spring and summer the last 2 years.

John Deere replaced one of the coils last year and she worked for awhile. then she went bad again.


Thanks,

Broski....

 

[mfreund]

Re: RPMs

Check the coils that were not replaced. I had a 322 and all 3 went out 1 after the other about 15 hrs apart until all were new.

 

[broski]

Re: RPMs

Thank You Mfreund.............

 

[jenkinsph]

Re: RPMs

I agree to check the coils again too. I was thinking this morning about all the things that could experience a delayed failure after a 5-10 minute period. Coils are slow to heat up and could very well be the problem. If you consider for a moment that these are machine made parts then a whole batch of them may be defective, further since sold to Deere in group lots it is easy to imagine that all of the coils on your tractor are from the same batch.



Steve

 

[broski]

Re: RPMs

Thanks for all your help.


Broski...............

 

[broski]

Re: RPMs

Guys, just got off the phone with the John Deere repair guy. I told him about my old problem with the RPMs, and the new one with the current RPM situation.

He checked his file when I had this problem 2 years ago. He now tells me that people are having the same problem with different J Deere equipment.

He said that the 10 percent ethanol might be giving the engines a problem.

I drained the tank and got some of the dirt from the bottom removed. I will put a higher octane fuel, and see if this solves my dilemma.

Thanks again.....



Broski

 

[mfreund]

Re: RPMs

Please keep us updated if that fixes it.

 

[jenkinsph]

Re: RPMs

Not to change the topic but on the boating forums I have read about lots of ethanol related problems, most of us boaters keep Stabil in all our fuel tanks.
Gasoline isn't what it used to be. Today gas is a **** of a solvent and will destroy old style fuel lines from the inside out, the ethanol will absorb the water in the tank and make a mess. Don't know if this is your problem but worth checking out.



Steve

 

[broski]

Re: RPMs

O. K. I put 93 octane in the john Deere 325. She ran about 10 minutes longer then previous, then the RPMs dropped as usual.

I am assuming it is one of the coils that they replaced 2 years ago.


I guy I work with who repairs these machines thinks it is some dirt in the carburator that kicks up after a while then lowers sthe RPM.

Got to get her fixed, the lawn looks terrible.

Thanks.


Broski........

 

[broski]

Re: RPMs

After 2 days of having the 93 octane gas in the john deere the unit ran about 20 minutes and then I lost 1/2 of the RPMs again. It seems to me it is the coil, the same problem I had 2 years ago.

I will have to make an appointment with deere this week.

 

[broski]

Re: RPMs

Ran the mower 2 times yesterday. she ran for about 15 minutes and then the RPMs lowered. The second time I ran her, she ran for about 20 minutes and then the RPMs lowered again.
Later on I ran her, and she ran consistently to complete the lawn. I don't know if the 93 Octane finally cleared the system or what.

When it did this 2 years ago, they replaced 1 coil and that solved the problem.

She never does this in the winter. She runs consistintly in the cold weather.

 

[broski]

Re: RPMs

Mowed the lawn the last 2 days, and the RPMs stayed up like normal.


One buddy of mine said there might have been some dirt in the carburator bowl that was causing the original RPM drop.

I will check it out the next few days. If the RPMs drop again, I will bring it to J Deere and let them sort it out.......

 

[broski]

Re: RPMs

The last 2 days I have been mowing with the 93 Octane gas. The 318 John Deere has not lost the RPMs. Maybe the higher octane blew some bad stuff out of the carb. If it happens again, I will take it to the Deere people, and see what the problem is.

 

[mfreund]

Re: RPMs

You might try some carb cleaner mixed in the gas. My mechanic recomends Chevron with Techtron. It is not the cheapest but works well for me.

 

[broski]

Re: RPMs

Thanks, I will try the carb cleaner.