Robins 295 won't start after rebuild
 

I sent off my Robins 295 and had it rebuilt. I received it back and after 9 months finally dropped it in my ezgo txt. I kept it in my garage and covered and all of the ports covered. I am trying to get it running now and it turns over great, but it will not fire or pop. I have had the spark plugs out and they seem to spark good but I spray starting fluid into the carbureator and nothing happens. It just continues to turn over but never fires. I have not contacted the company that rebuilt it for me yet as it is usually something I have done but I can't seem to figure this out. I have a fairly good mechanical background but sometimes I just miss something. I have brand new NGK spark plugs in it as well.

Thank you for any help
Kevin

Re: Robins 295 won't start after rebuild
 

May sound crazy but often overlooked is the battery being connected backwards and engine spinning backwards...

Not casting stones but where was the engine rebuilt?

Re: Robins 295 won't start after rebuild
 

Gotta check all the basics:

1. Good fuel flow/pressure to carb
2. Compression, check procedure for your engine
3. Good spark, use a spark tester
4. Good air to the carb, no obstructions

I'm not a fan of using starting fluid as a diagnosis tool. I've seen perfectly good engines crack in half using that stuff improperly.

One thing I do is remove the fuel line, remove the air filter and intake, spray good clean fuel from a spray bottle into the carb as it's being cranked, may take two people. I do this while in neutral, of course, or have the wheels up in the air safely. If the engine won't run on fuel sprayed directly in the carb, it won't run.

Re: Robins 295 won't start after rebuild
 

Engine was rebuilt at Precision Engineering in Saint Louis.

Since this post I pulled the timing cover off and it was NOT timed correctly! I timed it correctly and set the valves to .004.

It still does not run. Compression is only 70. Could this be the valves were not lapped?

Re: Robins 295 won't start after rebuild
 

If the timing was off it could have bent a valve

Re: Robins 295 won't start after rebuild
 

They should change their name to "Not So Precision" :lhmo:

Really though, I'm not sure how that happened but I agree, check the valves. Also check the top of the pistons for damage. Document everything, sounds like you might have recourse with the rebuilder?

Re: Robins 295 won't start after rebuild
 

Or maybe timing belt is still a tooth off. May have “adjusted” slightly once tensioned. You have to have the non-tensioner side of the timing belt pretty tight and all the slack in the belt on the side of the tensioner pulley. That way the tensioner takes up all the slack. If there was any slack on the other side, it may still be a bit off

Re: Robins 295 won't start after rebuild
 

I checked the timing AFTER I put the tensioner on to make sure the marks were still aligned.

Re: Robins 295 won't start after rebuild
 

It was just a shot in the dark. 70psi is way low. Should be more like 170+ psi on a fresh rebuild. Maybe put an a ounce of oil in the spark plug hole and check compression again. If it comes way up then they built something wrong in the bottom side (rings, cylinder bore). If it doesn’t change, then something is wrong in the top side(valves, head gasket).

Make sure to hold the throttle wide open by hand on the carb when checking compression. If the throttle isn’t allowing full airflow into the motor, less air going into the motor is less air to compress, which will result in a lower compression reading. Don’t trust the gas pedal to hold it wide open, I always do it by hand.

Re: Robins 295 won't start after rebuild
 

How did you line your timing marks up ? There is a dot on the bottom gear but it has nothing to do with timing these engines. Easy to mistake for timing mark. Not sure why Robbin even put that dot on bottom gear to begin with.

Did you check the compression before you changed the timing ?
Is yours timed like the picture I uploaded ?

Just asking because it can be done wrong if you didn't have a repair manual.

I agree with CP241. Check that compression holding throttle wide open with your hand or you will get a false reading.

I have seen them show low compression readings if throttle cable is broke or not connected correct so make sure that throttle is wide open.

I went to a shop last week to help a friend who had just installed a rebuilt 295 engine. Sure enough the throttle cable was not moving. I reached over and manually opened the throttle when he spun it over and it cranked. :shock:

How far was the timing off before you changed it ? if it was incorrect from the rebuild person ? .

Like CP241 said. If you put a teaspoon of oil in it and compression don't move then you have problems with the valves. Could be bent like kgsc stated. I never seen one bend a valve and I am not even sure these are interference engines .

Looking at Precision Engineering's website they look legit . Hard to believe they made that mistake but things happen.