:MTF_wel:
It look like the timing is off, did you check the basic timing? TDC (top dead center)? Flywheel key?
It look like the timing is off, did you check the basic timing? TDC (top dead center)? Flywheel key?
JD 165 Hydro Driving Me Crazy
Hi everyone....i've seen how helpful everyone here is and hope someone can give me some suggestions. Here is what I've got.
I bought an older but in relatively good condition JD 165 hydro from a guy around the corner. He was the only owner, had it serviced by the local JD dealer every spring. One day it wouldn't start. He took it to the dealer...they got it going, he brought it home and mowed the lawn. The next time he goes to mow, no start again....back to the dealer, and this time he goes home with an X300. (I know the dealer....they rather sell than fix) So i bought it, I don't mind a winter project....
Everything seems to be working right, but it just won't start. It gives nice puffs of smoke through the carb when the air cleaner is off.
So I start with the basics...spark? Check...just in case i got a new plug...still doesn't start, but now really pops back through the carb. Check the fuel, pump works great and plug is soaking wet....just in case give a shot of gas in the carb and in the spark plug hole....nothing. Compression...90 pounds. Pull all the shrouds off and check the flywheel key...which is good, and the coil air gap...good. Pull of the head...check cylinder...seems to leak a tiny bit of oil with each stroke from around the piston...and check the valves...intake doesn't have enought clearance (just) so pull the spring and valves, lap them, adjust clearances and reinstall.....
At this point I figure i'm good so reassemble everything and give it a whirl....same popping through carb....agggghhhh. This time, I give a shot of oil in the intake.. (saw somewhere that this can sometimes seal a bad intake valve long enough to start engine...and help diagnose the same)...no change.
Went out and bought a cylinder leak down tester (the nice part about working on things yourself...the ability to justify new tools
Did a leak down test...can hear whistling through the carb...nothing through muffler, but when i pull the top off the dipstick I have a oil volcano.
Pull it all apart again...maybe i made a mistake....check valves seating...seems to be good to me (i checked with a feeler gauge and by backlighting them in a dark garage) They seem to be seating perfect.
I'm stumped. I'm inclined to rip apart the engine and see if maybe the camshaft is out a tooth (bad timing). I've also been considering the spark....maybe its worth it to try a new coil before i rip it down totally. And then the leakdown test...how am i hearing air through the carb and past the rings if i have 90 pounds compression....should i just do a rebuild?
Sorry about the length of this post...any input would be greatly appreciated.
G
I bought an older but in relatively good condition JD 165 hydro from a guy around the corner. He was the only owner, had it serviced by the local JD dealer every spring. One day it wouldn't start. He took it to the dealer...they got it going, he brought it home and mowed the lawn. The next time he goes to mow, no start again....back to the dealer, and this time he goes home with an X300. (I know the dealer....they rather sell than fix) So i bought it, I don't mind a winter project....
Everything seems to be working right, but it just won't start. It gives nice puffs of smoke through the carb when the air cleaner is off.
So I start with the basics...spark? Check...just in case i got a new plug...still doesn't start, but now really pops back through the carb. Check the fuel, pump works great and plug is soaking wet....just in case give a shot of gas in the carb and in the spark plug hole....nothing. Compression...90 pounds. Pull all the shrouds off and check the flywheel key...which is good, and the coil air gap...good. Pull of the head...check cylinder...seems to leak a tiny bit of oil with each stroke from around the piston...and check the valves...intake doesn't have enought clearance (just) so pull the spring and valves, lap them, adjust clearances and reinstall.....
At this point I figure i'm good so reassemble everything and give it a whirl....same popping through carb....agggghhhh. This time, I give a shot of oil in the intake.. (saw somewhere that this can sometimes seal a bad intake valve long enough to start engine...and help diagnose the same)...no change.
Went out and bought a cylinder leak down tester (the nice part about working on things yourself...the ability to justify new tools
Did a leak down test...can hear whistling through the carb...nothing through muffler, but when i pull the top off the dipstick I have a oil volcano.
Pull it all apart again...maybe i made a mistake....check valves seating...seems to be good to me (i checked with a feeler gauge and by backlighting them in a dark garage) They seem to be seating perfect.
I'm stumped. I'm inclined to rip apart the engine and see if maybe the camshaft is out a tooth (bad timing). I've also been considering the spark....maybe its worth it to try a new coil before i rip it down totally. And then the leakdown test...how am i hearing air through the carb and past the rings if i have 90 pounds compression....should i just do a rebuild?
Sorry about the length of this post...any input would be greatly appreciated.
G
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You can do the same test wit a screwdriver.
Put the screwdriver in the wire spar plug hold the screwdriver close to the engine head or engine block (don't touch the steel part of the screwdriver with your hand) and crank the engine.
You should be able to see spark from 1/8" to 1/4" ( car go up to 1/2") and hear the tic tic sound of the spark.
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Put the screwdriver in the wire spar plug hold the screwdriver close to the engine head or engine block (don't touch the steel part of the screwdriver with your hand) and crank the engine.
You should be able to see spark from 1/8" to 1/4" ( car go up to 1/2") and hear the tic tic sound of the spark.
Ok...so I just finished relapping the intake valve and checking the lash..now it's all good. Put it all back together...for the umpteenth time..and no go...it just sputters harder now, but now its out of both the carb and the muffler. I checked the flywheel key again...it's not sloppy at all. I double checked compression...now i'm 100+.
So now the intake valve and the timing are basically ruled out (now that it's backfiring out of both ends The sparkplug is still wet so we are good for fuel.
I decided to go with BOSOX and stladrill and double check the spark strength....and i think we may have the culprit. When i test it by holding the plug near the head and cranking over i only the the odd random spark unless i'm almost touching the head. I'm going to go out on a limb and blame the coil. The only thing that bothers me is that it checks out as per the Kawi tech manual specs. The ignitor just gives me 27 KOhm no matter which way i test it. When i unplug it i'm totally sparkless...i'm going to assume this means that it works. Has anyone ever had a coil that checkout out but was just really weak?
Thanks so much everyone...i feel I'm getting closer!!
So now the intake valve and the timing are basically ruled out (now that it's backfiring out of both ends
The sparkplug is still wet so we are good for fuel. I decided to go with BOSOX and stladrill and double check the spark strength....and i think we may have the culprit. When i test it by holding the plug near the head and cranking over i only the the odd random spark unless i'm almost touching the head. I'm going to go out on a limb and blame the coil. The only thing that bothers me is that it checks out as per the Kawi tech manual specs. The ignitor just gives me 27 KOhm no matter which way i test it. When i unplug it i'm totally sparkless...i'm going to assume this means that it works. Has anyone ever had a coil that checkout out but was just really weak?
Thanks so much everyone...i feel I'm getting closer!!
I am still wondering why your compression is so high. Can you turn the motor over by hand with the plug in? Mine tests at about 58 and I can just get the compression stroke to turn with both hands on the screen on the flywheel. I am an average guy, average strength. My opinion though. 100 pounds you probably can't turn it over by hand.Ok...so I just finished relapping the intake valve and checking the lash..now it's all good. Put it all back together...for the umpteenth time..and no go...it just sputters harder now, but now its out of both the carb and the muffler. I checked the flywheel key again...it's not sloppy at all. I double checked compression...now i'm 100+.
So now the intake valve and the timing are basically ruled out (now that it's backfiring out of both ends
I decided to go with BOSOX and stladrill and double check the spark strength....and i think we may have the culprit. When i test it by holding the plug near the head and cranking over i only the the odd random spark unless i'm almost touching the head. I'm going to go out on a limb and blame the coil. The only thing that bothers me is that it checks out as per the Kawi tech manual specs. The ignitor just gives me 27 KOhm no matter which way i test it. When i unplug it i'm totally sparkless...i'm going to assume this means that it works. Has anyone ever had a coil that checkout out but was just really weak?
Thanks so much everyone...i feel I'm getting closer!!
I think someone else had the same issue with a coil. Dealer told them it checked out a couple of times. It was ultimately the problem. Have you checked your flywheel magnets? The manual tells how. It is sparking occasionally, just not every time. Or... as I type I am looking at the manual, does the plug wire have any breaks in it? Could be shorting on the way to the plug.
Be positive, we will get you through this.
1 - 20 of 35 Posts
