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Need help with my 2.5R...

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A

AC48

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I've been having problems with my 2.5R lately. I cannot get the darn thing to start :shrug: I was running it in the sand pit and all of the sudden it just stopped. No big deal I thought so I went home put some ARO in and didn't have anytime to run it for a while. I picked it up the other day and just could not get the damn thing to fire even once.

I am using the EZ start to turn it over but I use a glow ignitor, not the little wire that goes to the plug. I know the ignitor is fine, I use it all the time on the SP1. I have tried three glow plugs, one I an sure is fine cause it works fine in my B3. I know its not the right plug for the engine but I thought I would see if it would at least start, nothin.

Today I tore down the mill. I did not see anything out of the ordinary except for some rust on the crankshaft. It was kinda odd cause the rest of the engine is shiny new cause it has only a quart or two on it.

I took the carb apart as well and cleaned as best I could. I don't really know what to do once I get into the needles and everything, but the carb is where I think my problem is. I don't think its getting fuel and I think the HSN is blocked becuase its nearly impossible to prime the engine. I take off the pressure line and blow as hard as I can and the fuel doesn't move. After a while I can get some fuel up to the carb but its not easy. Any thoughts?

I always ran the engine at 240ish and it always ran decent, better than I thought it would do. It still has lots of compression and is basically a new engine. I have not seen any scratches on the piston/sleeve or crankshaft, just some rust on the backplate and the large part of the crankshaft. Any ideas?

O yea, HPI 20% fuel is what I'm using...its almost brand new.
 
if it is not getting fuel maybe you have an air leak? check the fuel tank o-ring,seal the backplate and carb with high temp rtv sealant. make sure you header isnt cracked, replace fuel lines, check fuel tank for damage. I'm convinced 2.5r carbs leak regardless of how many precautions you take to keep it from leaking. IMO that is why the 2.5r is so hard to tune and won't hold a tune. hope this helps a little.
 
Well even if I did have an air leak I should be able to atleast make fuel flow to the carb wouldn't I? If I did it would run crappy but it always ran fine. If I take the fuel line off the carb I can shoot fuel right through.
 
There's a filter internal to the tank, it may be gunked up, as well as any other filter you may have inline to the carb. One thing I can think of is to remove the carb from the engine and open your HSN all the way and blow through the pressure line to the tank and then to the carb and see. Try blasting the hell out of the carb with some 1:1 carb cleaner and see if it clears it up. Or try blasting through the fuel line with compressed air but not a very high pressure, under 10psi for sure.
 
Let me know, the 2.5 can be a bitch but the R is a good motor. I had good luck with mine until the fuel tank o-ring went TU and that killed it.
 
Go outside. Throw it as far as you could and hope for the best. I really hated that motor. Well the motor was fine if you could have it tuned for more than 5 mins. Good luck.
 
It always stay tuned for me, it just decided to quit lol. I heard that maybe plastic pieces could have been in the tank from factory and got sucked into the carb. I'm gunna take out the HSN and clean as best I can.
 

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