Rtv400

eserv

Well-known member

Equipment
BX24, A1000 Kubota Generator
May 27, 2009
2,140
139
63
Hardisty, Alberta
I have a RTV400 ( air cooled Subaru engine with fuel injection) that is getting fuel into the engine oil in cold weather. Any suggestions?
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,205
1,889
113
Mid, South, USA
If you do a lot of low speed operation, it's considered normal.

The engine is basically a lawn mower engine. In other words, it was originally designed to run 3600 RPM continually with a load against it most of the time. In the RTV application, it idles most of it's life. The downside is that the engine oil never really gets hot enough to boil any moisture and/or fuel vapors out whereas if it were in a mower or snowthrower or something similar, it would get up to 200+ degrees and stay there until the engine was shut down. That heat is what keeps the vapors from building up.

The Kawasaki Mule 600/610/620 has the same issue.....in fact at one point I had a customer tell me that his had a blown head gasket, and he was not one to be told any different. Said it was getting antifreeze into the oil that way. And nobody could tell him any different.
 

1970cs

New member
Apr 26, 2016
1,124
3
0
Grand Ledge
The RTV 400 has a known problem with this! It will be fine and then it starts to run rough and then you pull the dipstick and it's inch over full with fuel dilution.

Since we bought one back with Kubotas help from a customer and he has a second one that only does it about 2 times a year. He said he could live with twice the other one was doing it once a month.

Kubota may have a fix now, but we have had not had one on the lot for close to 2 years.

Pat
 

eserv

Well-known member

Equipment
BX24, A1000 Kubota Generator
May 27, 2009
2,140
139
63
Hardisty, Alberta
We are a dealer too, in central Alberta Canada. We already installed the experimental air restrictor to try getting the engine to warm up. We installed a complete new engine in the fall because the compression was low and Kubota thought that might be the problem. I have no doubt this customer is put-puting around doing chores and idling the machine!