1986 TMC 102A3 - Slow Take off

[luvrbus]

If you want to check for a clogged muffler, you could install a pressure gage in pipe before muffler and note pressure with engine against governor. Under load would be better. Would need some hose and have someone read it from bedroom.

LOL it is a lot easier to check for a plugged muffler with a hand held IR temperature gun

[chessie4905]

But don't use one from Harbor Freight!lol

[jraynor]

Take that old war horse out and RUN IT.

Find a long hill, several miles long, one that brings it to its knees, and go back down and climb it again...

Don't come back for at least 2 hours of highway driving, longer if you're having fun.

report back.

happy coaching!
buswarrior

Ok everyone, I have an update from my drive today. I finally got to take the bus out today and I drove it for about 2 hours. No hills though as this is Florida not the smokies. I took it out on interstate 95 and had it running as fast as she would go. The bus got to a temperature of roughly 180. My thermostat only has ticks at 150 and 200 and it was just past middle between those two. She ran up to 75MPH and was really all it would do. As for smoke, very little if any smoke to begin with. After I got back I took her down the street and did some take offs. I get a small cloud of black smoke but only a little that you can still see through it. Wouldn't call it a cloud at all. I had one take off that was pretty quick but other than that, they were about the same. It seems to actually use all 4 gears this time which is good. It doesn't seem to skip 3rd.

As for the fuel filters, I have a fuel precessor so I can see how clogged my fuel filter is And it's less than half dirty. As for intake filter, box is clean and filter is in good shape. Tapped it with the handle end of the screwdriver lightly just to dump the lose dirt. I need to see if my model has the air flow indicator thingy that sits above the remote control box(the one with the rear start switch). I think mine has one but there's nothing connected to it?? That'll be for another day.

So what to check now? I'm wanting to look in for a tune up to see how that might help get some more power. No telling when it was last done

[luvrbus]

75 mph is about right on top end with a 6v92 and 3:73 gear,the throttle delay makes it slow on take off to prevent smoking,sounds like you have the typical CA 6v92TA engine 255 hp to 277 hp since it is running cool and not over heating as MCI intended it to do.You can bump the HP up to 350 if you want to fight the smoke and engine over heating that is your call,but it is best if left alone instead of opening a can of worms you will regret later JMO   

[Geoff]

Parlor buses in 1986 w/6V92TA ran 335HP.  Now if it was a a NJ Transit bus it may have been a detuned bus @ 277 HP.  You have to pull a valve cover and get the tag number off one of the injectors to see what you have.

[chessie4905]

I absolutely hate those temperature gages. Prefer something like this with more graduations.

https://www.vdo-instruments.com/instruments/by-series/singleviu/singleviu-2-1-16in-52mm-250-f-water-temperature-gauge-3341.html

[luvrbus]

You see a ton of MCI buses with 6v92TA @ 255 to 277 hp MCI didn't use high hp engines ,the standard setting on a MCI with a 8v92TA was only 365 hp in the C's ,lol bet you a quarter he has 9F70 or 9G75 injectors 

[buswarrior]

Most of your report sounds fine.

You knocked dust out of the air filter?

Go get a new one, it's done. As Tom YELLS, so shall I:

DON'T BLOW OUT an AIR FILTER.

If there's no smoking once she's rolling along, there's no tune up required.

1986, the 6V92 was positioned as a fuel economy choice against the 8V71. HP will be 277 from the factory.

Next project...

happy coaching!
buswarrior

[jraynor]

75 mph is about right on top end with a 6v92 and 3:73 gear,the throttle delay makes it slow on take off to prevent smoking,sounds like you have the typical CA 6v92TA engine 255 hp to 277 hp since it is running cool and not over heating as MCI intended it to do.You can bump the HP up to 350 if you want to fight the smoke and engine over heating that is your call,but it is best if left alone instead of opening a can of worms you will regret later JMO   

How well would this bus pull hills though? If it keeps from overheating, then I'm happy. I'll take the slow start versus an overheating engine any day. I just thought I remembered the bus having a better take off than it does, but maybe not

[jraynor]

Most of your report sounds fine.

You knocked dust out of the air filter?

Go get a new one, it's done. As Tom YELLS, so shall I:

DON'T BLOW OUT an AIR FILTER.

If there's no smoking once she's rolling along, there's no tune up required.

1986, the 6V92 was positioned as a fuel economy choice against the 8V71. HP will be 277 from the factory.

Next project...

happy coaching!
buswarrior

Just some dirt that had gotten sucked to the filter. And that's one of my maintenance items, just not the highest priority. Oil change is the highest priority. I have the oil, now just to get the change done. Is it best to get the engine warm ( I don't like saying hot lol) then change the oil? I possibly see myself building some ramps in the near future to make doing the oil a bit easier

[eagle19952]

Just some dirt that had gotten sucked to the filter. just not the highest priority.

it should be.
Detroit's suffer less on old oil vs. a filter you can knock dirt out of...even talc dust is a horror show waiting to happen

[Iceni John]

I absolutely hate those temperature gages. Prefer something like this with more graduations.

https://www.vdo-instruments.com/instruments/by-series/singleviu/singleviu-2-1-16in-52mm-250-f-water-temperature-gauge-3341.html

Or even better resolution, less than $80, custom-made to order in USA:  https://www.speedhut.com/gauge/G-WTR-01/1/Speedhut-Water-Temp-Gauge-120-260F
I think it's safe to assume that any original gauge is automatically suspect, unless it's known to be accurate.   The engine temperature gauge is the single most important gauge for a 2-stroke bus.

John

[chessie4905]

Yes any of your favorite brand temperature gauge. I also dislike 90 degree 0 to 4000 rpm tachometers.

[richard5933]

Or even better resolution, less than $80, custom-made to order in USA:  https://www.speedhut.com/gauge/G-WTR-01/1/Speedhut-Water-Temp-Gauge-120-260F
I think it's safe to assume that any original gauge is automatically suspect, unless it's known to be accurate.   The engine temperature gauge is the single most important gauge for a 2-stroke bus.

John

Have you found any that offer the green color on the pointer? Be nice if it looked like the original.

[luvrbus]

The Eagle with the VDO gauges had the easiest to read gauges of any bus ,if I redo my dash I'll bite the bullet and install a Sliverleaf Glass dash since they have came way down in price