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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Bob Gil on March 22, 2008, 08:11:16 PM

Title: 6V53 rpms power
Post by: Bob Gil on March 22, 2008, 08:11:16 PM
I know that my little engine does not have a lot of power.

But I can't stop wondering after I have driven it about 50 miles.  I have it feeding out of a 5 gal can thur an electric fuel pump and a new filter.  Is the fuel pump and the 3/8 inch line a restrictor that might not be allowing it to get the fuel it needs to rev up to the faster rpm's?

I am not sure if that is all of the problem i seam to feel a little restance on the pettel not allowing it to come back up when I take my foot off the pedell, it is all mecahial is this normal? 

Does it sould like I have more than one problem?
Title: Re: 6V53 rpms power
Post by: hargreaves on March 22, 2008, 09:14:43 PM
Most engine have a throttle delay on the rack on one head. it is a little piston that is clamped to the rack shaft. If this is not set right it will slow your throttle response down. remove it and try it without it. There is a small hole in the back of the cyl. that lets engine oil out slowly. If thats not it , the governor needs to be looked at and set up., or maybe even a tune up and setting the racks.. Good luck   Gerry
Title: Re: 6V53 rpms power
Post by: TomC on March 22, 2008, 11:56:07 PM
The 6V-53 is rated at 2800rpm, with revving to 3000rpm normal. If I remember right the torque is created at around 1800rpm, so the engine should stay pretty much in the 1800-2800rpm range.  Make sure the pedal works smoothly and hopefully you either have an air cleaner on it now or will in the very near future.  Good Luck, TomC
Title: Re: 6V53 rpms power
Post by: Sojourner on March 23, 2008, 12:09:14 AM
Find out via 2-cycle-diesel mechanic what is engine's governor set at....maybe too low??? Or pedal to engine is not wide open throttle.

I think you need someone that knows your bus model to drive test for power comparison.

FWIW

Sojourn for Christ, Jerry
Title: Re: 6V53 rpms power
Post by: Bob Gil on March 23, 2008, 09:56:22 AM
Yes I did put the air breather on before I moved the bus.  I still need one more 90 elbow to connect the breather to the side of the bus but it will not matter that much as the air is getting filtered now.

The old engine seams to run good it does not smoke when started and only a little when you first start moving.  It does not seam to smoke any time other than that.  I would have expected it to smoke a little when I started pulling a hill if it were at full rpms, trying to maintain top rpms.  This makes me think there is some thing not quite right.

Gerry I do not remember seeing any thing like what you described on this engine.  I might not have paid enough attention!  I will look again.

I did have my brother press the pedal to the floor and I played with the linkage at the rear of the bus and it seams to me that it could move further if the linkage were set correctly.  There seams to be some dragging in the linkage from one end of the bus to the other.  And looking at the linkage at the rear it seams crude.  See PIC  Washers welded to the firewall and the shaft going thru them with pins and washers holding the linkage up at the rear end.  And the pedal seams to come up more when you put you foot under it and pull it up.

I assume nobody thinks the 3/8 fuel line or electric fuel pump are the problem.  I was not sure since the other lines are about 5/8 coming from the tank.

As to find someone that knows this bus I don't think there is anybody that does, any more than you guys.  I have not been able to find out any thing from any body else that I have talked to and the things I have been told here seam to be right in line with what I am finding.  Too much of the original has bee covered up or taken away.  It seams to have the steering column out of a 80's GMC pickup in it.  Has the tilt wheel and dimmer on the turn signal switch along with I think the old cruse control too.  This needs to go as the tilt does not seam to want to hold as you put the power on it to turn the wheels when moving slow.

I will see if I can find come one that knows DD to look at the gov, mean while I will take my rpm counter with me and see what it is doing with no load next time I go down and hope to bring it home some time this week.
Title: Re: 6V53 rpms power
Post by: Dallas on March 23, 2008, 10:34:35 AM
Bob,

If you are using an electric fuel pump like they use to sell at the el cheapo auto parts stores, it may not be able to deliver enough fuel to run the engine, let alone cool the injectors, which can cause early failure of the fuel system.

The original fuel pump on those engines delivered 45 to 70 PSI at governed RPM.
Install a mechanical oil pressure gauge in the fuel line between the pump and the head.

Why doesn't this engine have a mechanical fuel pump on the engine? what is filling up the hole that it would have left when removed?

If you can get to the engine block, I believe that down below the head on the drivers side at the water pump end of the engine is a pad with some numbers stamped into it.
If you will get those numbers and post them here, I will be happy to send you the tune up specs for that particular engine.

BEWARE doing a tune up (running the rack) on the 2 stroke Detroit is not a simple matter and takes a certain amount of finesse. It's not for the faint of heart or for anyone who cannot follow directions to the letter.

Good Luck,

Dallas
Title: Re: 6V53 rpms power
Post by: Bob Gil on March 23, 2008, 10:52:41 AM
Yes I am using a cheap O that was with the bus when I got it.  I think the original use was to prime the fuel system.  I use it to make sure the fuel is pulled up to the system.  The fuel pump you speak of is still there.  i have not messed with that. 

I was afraid that the delivery system I had was causing it to not get the amount of fuel it might need to run the higher RPMs.  I tested it and the fuel will go Thur the electric pump if the pump on the engine will pull it.  Is the size of the line a problem?

in the picture you can see what I had to start with. 

I have put a new filter in place (a lot bigger than the old one) I got the filter # from you guys.. I did not get both of them replaced as the lines are going to need to be remade to make things right.  But you can see the can I am running out of the fuel pump.
Title: Re: 6V53 rpms power
Post by: makemineatwostroke on March 23, 2008, 11:07:41 AM
Bob,put your fuel system back in place and things will start to go better for you like Dallas said that engine is not going to rev up with out the correct fuel pressure  just work on one item till you fix that problem and the stress level will be lower