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Discussion Starter #1
I have a cag with the big bore 51cc motor. I bought the motor complete with the carb and mounted it in the bike.

I have had a lot of trouble with the carb. It's tough to start. It dies when its hot and wont restart. Gas leaks from the throat while its sitting. I've adjusted the float several times and it starts leaking again after I ride.

Here is a link to the carb
Deltoro Racing Carb


I was looking at it again and I'm starting to wonder about the angle of the carb. Its leaning slightly downward. Is this normal? I don't believe I put the intake on upside down. I think it only fits one way?

I talked to the seller several times about it and he sent a replacement and I've had the same symptoms. I'm hoping I just did something stupid you all can point out.
 

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But who prays for Satan?
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I think the angle is wrong, flat is good, a bit of a tip into the engine is ok, but not kicked back like that, the float wants to be pretty flat, and gravity (when the carb is tipped into the engine) will pull the fuel into the case, right now it's pulling it away.

*I think* :):thumbsup:
 

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Discussion Starter #3
After looking around I see a metal intake that seems to have a better angle on it. I wonder if the intake int he kit just isint right for the bike
 

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No that is a Cag kit, the problem is the carb is to Big, has three 3 jets, the stock jet is probably too big, and there are no smaller one unless you can make your own. Go read Cam2s Cag, Cag Cag, post he goes thru running it on a Modded Cag.
 

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I bought a engine from this website also, Have not got to run it with exhaust, but when I did let it run I did not see any issues
 

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I put the same carb on my 5 port engine and I had to mega modify it to work right...........

Youre right about the angle and the leaking problem......I made a thin steel hanger that hooked under the carb airfilter clamp and fastened it to the seat crossbar to raise the angle........

I first did it with thick copper strand wire as a tester first but after reangling the carb it worked pretty good but not as good as my WT603 w/boost bottle nipple in the hp manifold....

To see how I got the deltoro carb to run the best it could on my engine check out my cag build thread.......

http://www.pocketbikeplanet.com/f82/cag-cag-cag-oh-yeah-cag-60828.html

 

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Discussion Starter #8
Thanks for the ideas. I'm going to try raising the carb to make it level as CAM2 suggested. If it runs better I might take a chance on the this metal intake. It seems to have a better angle and without the worry of the rubber intake collapsing I can adjust it more if needed.

I've also toyed with the idea of spacers on the rear engine mount screws to tilt the motor up if the exhaust will allow.
 

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Thanks for the ideas. I'm going to try raising the carb to make it level as CAM2 suggested. If it runs better I might take a chance on the this metal intake. It seems to have a better angle and without the worry of the rubber intake collapsing I can adjust it more if needed.

I've also toyed with the idea of spacers on the rear engine mount screws to tilt the motor up if the exhaust will allow.
Thanks Nick............

That intake is way smaller than 19mm's..................... I had that carb setup aswell and ill tell you your wasting your loot.....That manifold is only 14mms and will require a downstepped silicone rubber coupler with 2 clamps like I had to do to get that carb to fit on my PW80...........



For your exhaust problem take a plumbers torchhead with yellow mappgas and heat up the spot and bend it to fit..........Its easy to do....

This pipe had a straight top pipe before the 45 degree bend...on one of my cag builds I needed more bend to the straight part so I made the appropriate changes with a turbohead torch w/yellow mapp gas before cutting off what wasnt needed............



 

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But who prays for Satan?
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ha hah, Those tricky little so and so's are
the outside diameter of the manifold, and comparing it to the INSIDE diameter of the carburetor.

CAM is totally right!

the normal way to mount the phbg's is in the rubber manifolds!
 

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That manifold is for a 14/14mm Dell SHA Rep carb, forget putting a 19mm on it. I have 3 of both carbs, the 19mm and the 14mm, the 14 Del is not any better. Sent your stock 12mm Cag carb to Boosted306 and for $20 he will Swirl taper bore it out to 14mm re-jet and send it back to you and they work great. $95 and a 10mm FC and Sam will turn your stock engine in to a Screaming Motor.
I taper bored and thru bored a 14/14 Dell SHA Rep carb to 16/15mm bored out the alum piece to 15mm, one jet size up, put it on my 40cc Polini Rep engine.
 

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Discussion Starter #14
Hmm, that's very deceiving. Thanks for clearing that up.

Ok, I just had another idea. I don't know the origin of this bike. When I got it it was in pieces. Perhaps the motor mount platform was bent. What if I apply some force and bend the mounting plate down at an angle to level the carb?
 

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You all ready have a 2 pcs Alloy Head, B/B already. You can change the compression piece, in the head, in 5 minutes. Its my favorite engine style of the Big Bores, and I have 2 Sam's 3rd Stage 3 piece heads, better cooling but 6 screws and take two pcs off to tighten the head bolts.
On my Blue Demon engine I releaved the top of the starter cover so I can get to the bolts without taking it off.
Do, you have a full circle crank, or stock crank?? They both come in 10 and 12mm rod bearings.
If you move the angle of the engine it will change the angle on the end of your exh pipe. I like the carb pointing down a hair, so the gas runs out the front not flood the engine. The angle don't look that bad to me. If you bend the mount plate, better weld a brace underneath.
 

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Hmm, that's very deceiving. Thanks for clearing that up.

Ok, I just had another idea. I don't know the origin of this bike. When I got it it was in pieces. Perhaps the motor mount platform was bent. What if I apply some force and bend the mounting plate down at an angle to level the carb?
With some heat from a plumbers torch it just may budge easy enough to work.......These frames are welded and assembled by chinese kids so every frame is a littlebit differently built,,,,,,,,,,,,,,Customizing is a must on most cases...............
 

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Discussion Starter #17
ERP, Not sure exactly what the internals are. I bought the the engine online assembled. Even with the carb issues it does really well when it runs. I'm 190 and it pulls me faster than I care to go.

CAM2, I was going to try removing the motor and standing on the platform. I really only need a few degrees. Actually I think there is enough play in the muffler hanger to make it work. If it doesn't work at the manifold side I'll try heating it with some MAP gas.
 

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You might try some vibration washers, rubber on one side, steel on the other, about 20 cents apiece, stack 2 or 3 in the back engine mounts and 1 up front, that will rasie the rear without modding the plate. and help with vibration at the same time. Stack them rubber to rubber where you can. Play with it till you get what you want. You might used a steel washer with the rubber till you get the right height.
 

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The angle for a Dellorto carb is up to a 30 degree angle is ok. But I have seen alot try to run the 19mm on a cag engine and it never worked out to their liking or what they expected. Its to big!!!
 

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Discussion Starter #20
ok, I needed to replace the clutch as well so I pulled it all apart. One of the clutch springs that loose so they sent a new one. Odd, there was no woodruff key in the clutch, was beveled to squeeze onto the shaft...thats another thread.

I was able to bend the motor mount down at a more level angle. I'll put it all back and try again.

Is StrayDawg63 right? is that too much carb even for the .51 BB? Odd they would sell me a motor with a carb that wont work.
 
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