No gas!

[Andreas Piepke]

Hi All,

Today I wanted to do the first test run of my rebuilt 1973 Penton Hare Scrambler. At least that was the plan. I can't start the motor as there is no gas going into the float bowl, even when holding down the tickler. I am now trying to remove the float bowl to inspect the floats to see whether they are somehow stuck, but I can't get it off, not enough clearance between carburetor and engine case. The following picture shows the situation:



1) Is there any obvious reason for gas flow blockage? Gas flows out of the supply line freely.
2) How do I get the float bowl off without disassembling the carburetor? Is there some must-know trick? I would think that one must have access to the jets without prior engine removal!

I had hoped for some two stroke sound but only got a gasoline bath!

Thanks for your input!

Andreas

[454MRW]

Loosen the front and rear clamp and rotate the carb to remove the float bowl. The needle valve is probably stuck. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Andreas Piepke]

OK that worked. I could rotate the carb to remove bowl. I wiggled the needle a few times and the bowl fills up now. There seems to be only minimal clearance to move the float bowl out of the way though. In the process I broke the cork gasket (darn), Al can look forward to another order.
Even after kicking the engine over many times it won't start and I can't see any fuel on the spark plug. I don't think I am getting fuel into the cylinder. I will need to puzzle over this one for a little while I am afraid. Michael, thanks for your input, this certainly brought me forward.

Andreas

[Daniel P. McEntee]

How certain are you of the float level? Does the carb over flow when you tickle it? Little things will cause big problems and give you proportionate headaches!
   Good luck with it,
    Dan McEntee

[454MRW]

Starting a KTM engine usually requires holding down the tickler until fuel starts to dribble out of the overflow hoses, then I usually kick it over 2-3 revolutions slowly with the kill switch held down to keep it from kicking back, then one swift kick should get it to at least fire or even start. The colder the temp, the more they like fuel on start up. If you can't get any dribble out with the tickler, then you can lean the bike over until it dribbles out. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Andreas Piepke]

Yes, the carb does overflow when I hold down the tickler. I probably kicked it over some 50-times or more with throttle open or closed, pet cocks open or closed etc. When inspecting the spark plug I would have expected some gasoline on it but saw or smelled nothing on the plug. There is no audible trace of ignition. This leads me to believe that gas doesn't make it into the cylinder. But I will try your method, to be sure. Maybe Dan's hint at the fuel level in the bowl is the right track, I don't know.
I am riding a Norton (on the side so to day). Brit bikes usual start when you flood the bowl real well. So I tried that but to no effect. I am no stranger to swift kicks on the lever!

Thanks for your input, I really appreciate you help. I want to get this thing running now!

Andreas

[Paul Danik]

I have heard that sometimes "others" will put a few drops of fuel into the engine down the spark plug hole. sounds a little shaky to me... But, from what I have heard, sometimes a balky machine will come to life....possibly this could be referred to as "manual fuel injection", but obviously I would never suggest this type of fuel-lish-ness...

Paul

[Daniel P. McEntee]

I had a Hodaka Wombat that I built up by mixing and matching the best parts from two donor bikes, and went through the engine to replace bearing, seals, rings and such. When it came time to start, it fired a little bit on the first kick, then absolutely nothing, not even a pop over the next several days. Went through the ignition, checked and changed everything twice! I posted my troubles on the VINDURO list and Ed Chestnut responded with a similar story on a Wombat engine he built up from all new parts. Ed was the service manager for Hodaka back in the day, so you can imagine the fit that this put him in, Finally he decided to tow and bump start the bike, and had success. After that it started 1st or 2nd kick every time. I followed his advice and after towing it about 50 feet or so, it fired up and ran normally, and started 1st or 2nd kick every time after that! I was sure I was getting fuel through all of that, though. The dry plug makes me curious. Try Paul's advice of putting some premix down the spark plug hole, just a tea spoon or so, and see what happens.
  Keep us posted,
   Dan McEntee

[Andreas Piepke]

I'll first remediate the cork gasket I broke (the carburetor is now leaking and I don't want to have a bonfire) and then try the "enriched mixture". I'll keep you guys posted when I manage to start the bike.

Thanks for your input!

Andreas

[tofriedel]

Andreas,

Use some gasket sealer on the float bowl gasket.  That should eliminate the leakage at that site.  Just to make sure, is the timing correct and are you getting spark at the plug?  If either one of these do not exist, it will not start.

Tony

[454MRW]

An all too common mistake is to leave a rag or wad of paper towel in the intake or exhaust port, that was originally intended to keep dirt/debris out of an newly rebuilt engine. I purchased a 78 RM400 this past summer from a individual who was moving and the engine had locked up after kicking it over several times before he was able to get it started after a top end rebuild by the famous engine builder/modifier Eric Gorr. The individual was sure the kick starter had locked up and didn't have the time to tear it down and fix it, so he sold it to me. Upon taking the head off, I found a black ankle sock that was in the exhaust port had worked its way partially into the cylinder and jammed the engine tight. It never hurts to double check! If it can't breathe, it can't pull in fuel. A plugged up exhaust pipe will do the same thing. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Andreas Piepke]

Yea, I already thought about this possibility but dismissed it based on: "no I wouldn't have done that..." If nothing else helps I will peek in there. I really hope to get the bike running over Thanksgiving. The last thing missing after that: painting of the tank.

Thanks for the brainstorming!

Andreas

[454MRW]

Maybe not, but mice love introducing nuts and other items into pipes even hanging in the shop. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Andreas Piepke]

I took the carburetor off and looked into the engine by means of a small mirror and a lamp: nothing is stuck in the inlet or exhaust, at least as far as I can see. I replaced the gasket between the float bowl and the carburetor body. This is how the under side looks like:



I tested the level of the floats using the method described in the repair manual and found them to be correct. I probed the rear end of the exhaust with an elastic metal rod and found that I can put it in until reaching under the tank. The float needle moves freely. When taking out the holder of the float needle I found some hardened sealant that fell off. Does sealant belong there?
I put 1 ml of pre mix into the plug hole. The engine came to life for a few rotations of the crank but then died down, it wouldn't rev. I further see that the carburetor is leaking.
They only thing I see now is to replace the float needle with one with a rubber tip from Al. The one that is in my Bing 54 has a polished steel tip. It also seems very difficult to seal the fuel lines against the carb and the T-piece, connecting it to the two petcocks, even when using hose clamps (maybe Teflon tape would help). Maybe I need to gain access the front end of the exhaust and probe it with a wire to assure that its free of stuff.
This seems a difficult problem to solve! I had hoped for a Thanksgiving weekend test run but it probably ain't gona happen.

Cheers

Andreas

[Paul Danik]

Andreas,

  When you pull the carb off is there much fuel in the bowl? Is the carb leaking out the overflow or just leaking from  

  I realize you set the float in the way that you feel is proper, but I wonder if it is correct, no offense intended, just trying to help.

  With the carb off the bike and the float bowl removed. With the carb upside down and level, if you blow into the fuel line and slowly lift the float upward from its resting position, does air start to flow thru the fuel line when the float becomes level, if not when does it start to flow?

Paul