Kubota B7100 difficult start

[parallax]

Hello everybody!

I noticed my 1983 kubota b7100 (1400 h on odometer) has a quite difficult start. It doesn't start in the hot days without preheat. Tractor is in Romania now, bought it from UK. Tested it in August (30+ Celsius) without preheat and didn't start. Now I have to use preheat button for about 30-40 sec, and will start. When it starts you can see a bit of white smoke and then black smoke coming out. Please see the attached video link and tell me your opinion. Do I need to change anything on this tractor? Like glowplugs, injectors? I don't have any history about it, I mean I don't know when they changed the glowplugs (if they did it). Straight after I bought it, I changed the oil, filters, cleaned the tank and I put the best diesel in.

Thanks for your help.

 

[North Idaho Wolfman]

Looking at the video, and what I know from mine that looks to be normal.

If your not getting excessive blow-by out of the vent off the valve cover then everything should be right.

These little monsters have indirect injection so they are a lot harder to start when they are cold, newer designed diesels have direct injection.

Manual states Pre heat 60 sec, so if 30 works your still better off.

 

[parallax]

Thank you Wolfman for your opinion, I don't get any smoke while plowing, so I am thinking it might be some glowplugs fault in there? When I preheat and start it, it feels that it is struggling a bit to start. I would like to replace the glowplugs , any idea about some good quality ones? Cheers

 

[Tom in Arizona]

The video looks just like the way my 79/80 B7100 starts. I preheat for 15 to 30 sec. at the beginning if it is chilly.

 

[parallax]

The video looks just like the way my 79/80 B7100 starts. I preheat for 15 to 30 sec. at the beginning if it is chilly.

Do you use preheat even in hot days like 30+ Celsius?

 

[Tom in Arizona]

Do you use preheat even in hot days like 30+ Celsius?

Yes, about 15 sec. on the first start of the day. After the first start, no.

The tractor is used down in the Phoenix area where that is a cool day during the summer.

 

[parallax]

Thanks Tom for your replys, mine starts very difficult in the hottest days without preheat even if stopped for a half an hour before...we have very hot summer in South Romania. I don't mind to use preheat every start, just wanted to know if it's something normal.

 

[Sledge]

Perfectly normal, for my mid 80s B7001 at least. Lots of smoke but never fails to start, and no smoke after that. On cool days I have to use pre-heat even after stopping for only 15-20 mins, but again it never lets me down.
I do worry I'm flattening the battery with 60seconds pre-heat so I usually keep to 20-30s but that's still adequate.

 

[Piker]

Thank you Wolfman for your opinion, I don't get any smoke while plowing, so I am thinking it might be some glowplugs fault in there? When I preheat and start it, it feels that it is struggling a bit to start. I would like to replace the glowplugs , any idea about some good quality ones? Cheers

My 1980 B7100 always requires the glow plugs to start = 6 clicks on the hour meter or 60 sec in winter weather. Even after using it for gardening work & leaving it for 1/2 hr. requires glow plugs to start. It uses no oil, there is no sign of blow-by & has lots of power. Just the nature of the beast.

 

[lsmurphy]

Yep, normal.

 

[cb750k8]

I have a B7200 and your startup looks normal to me. Need to use preheat on glow plugs after half hour from last running. Need glowplug heating even in summer.
Cheers

 

[Apogee]

Perfectly fine and completely normal. Leave it alone and just use and enjoy it.

If you REALLY feel the need to work on it, disconnect the wire that hooks all of the glow plugs together. Then measure the resistance between the tip and the block on each glow plug. If you have a bad one, it will show open (0 ohms resistance)... You have to remove the jumper wire that connects to the other ones because otherwise you'll get false readings.

I believe NGK were OEM. Cheap to replace if you want to. Double check the number with those on your current glow plugs. It should be stamped on either the body or one of the flats like the pic shows (you might have to remove the paint):

http://www.amazon.com/NGK-Y103K-Glow-Plug/dp/B001B0WZR4

The only other thing to consider at 1600 hours might be to have the injectors checked to ensure their spray patterns are good. Bad spray pattern can also affect starting.

Again, based on the vid, I'd leave it alone and just use it.

Congrats on your new toy!

Steve

 

[parallax]

thank you a lot chaps for your opinion and advises. I am very happy to find good quality people on this superb forum. It seems it is something normal out there.
I have learnt a lot since I discover it. I will try to bring up subjects with video and pictures as I am sure there are many rookies like me on this forum regarding tractors.

 

[Tom in Arizona]

thank you a lot chaps for your opinion and advises. I am very happy to find good quality people on this superb forum. It seems it is something normal out there.
I have learnt a lot since I discover it. I will try to bring up subjects with video and pictures as I am sure there are many rookies like me on this forum regarding tractors.

By the way, have you downloaded the owners manual in Adobe Acrobat format. Forgot where I found it now?

 

[North Idaho Wolfman]

You can get all the manuals at:
Kubotabooks.com

 

[Apogee]

One other thought came to mind after I posted above. I would also definitely recommend checking the valve adjustments. If they are improperly adjusted it can affect starting.

Good luck and welcome to the forum!

Steve

 

[parallax]

wow, amazing how much info on that link, I had a manual but there's much more helpful info, I'll get them all
I am thinking to buy a new overhaul kit, just to have it there for when I'll be forced to change it.
I just want to mention that we've recently used the tractor for plowing in total around 1 hectare and the little kubota did a very good job. No smoke while plowing, apart of normal fumes because of the load. I will post soon some videos.
Thanks again for your valuable advises guys.

 

[parallax]

One other thought came to mind after I posted above. I would also definitely recommend checking the valve adjustments. If they are improperly adjusted it can affect starting.

Good luck and welcome to the forum!

Steve

Steve,
For the moment I will check the glowplugs and change them if any faulty. This winter I need to fix the holes and get rid of rust from the bonnet, change the back lights with the original ones I bought from ebay, wanted to repaint it all but changed my mind, I will leave the original paint As for the valve adjustments I will check them in the spring with a specialist when prepare it for new season.

Thanks a lot for your support

 

[Stubbyie]

I don't have one of this series of machines so I'm not intimate with their starting characteristics.

But I do know about using glow plugs, especially in cold weather. Cold or hot, using GPs heavily sure pulls the battery down---especially for short periods of use if the battery doesn't have sufficient run-time to recharge.

May I suggest--don't know if this applies to our overseas friends--installing an on-board battery maintainer hardwired directly to the battery? In the US, Schumacher makes a good one designed for mounting on the machine. I've had zero luck with Harbor Freight models. If you can't mount it, you can run wires and leave a polarized plug hanging loose that you can get to.

Sure makes a difference on starting and on battery life. If your machine(s) have the compression release you can pull the release 'on' and use your strong battery to spin up the engine before pushing the release 'off' and getting a good strong well-lubricated start.

We make it a habit on our rolling stock to pull into the shed and plug the battery in year-round. Like I said, makes batteries last longer and life easier.

Please post back with your experiences so we may all learn.

 

[parallax]

Thanks for the advices Stubbyie,

Well, I will keep an eye this winter and see how tractor starts, for the moment I am away, overseas in Middle East and tractor is in the shed back home. I don't know if I will fit a battery maintainer but definitely I will use extra power from a second battery booster just to save tractor's battery life. Tractor has a decompressing knob but the wire cable is stiff and didn't have the chance to fix it (clean it or change it) after I bought the tractor this summer. I didn't do much on this tractor as I had to leave with my work. When I will be back I will try to apply all the advices you guys post it here, thanks again . I will update this post.