Track Tac

Carb type and size

DD83 said:
if you are going to ask if your lash is too tight you need to provide what your have it set at. was it hard to start? It's really hard to help you when you're jumping all over the place before you attempt to use any advice you were given here. Not one time did someone tell you on this thread your carb was too big and to get another. Again you're working on a radical build no carb is going to be plug and play. stick with one and fine tune it....or box it all up and send it to someone that know's what they are doing.
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That's what I would love to do honestly, I would love to say here please help me cause I can't figure it out.
Valve lash per Jimmy (JRPW) said to set at 0 lash, pull cord snatched out of hand, we went to an external starter for that reason. I think lash is still at 0 I will double check on that.
 
Boomanchoo27 said:
It's a flat slide, everything seems to be in place correctly, nothing seems to be fitted wrong. It just that when I give it part throttle or full throttle the engine somehow does not like it and I don't know what that is or why. It has 32mm intake valve so theoretically the 28 should work on it. Stumped is my guess that and running e85r instead of good ole gas or methanol which I know absolutely nothing about.
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E85 is nothing but 85% ethanol and 15 % gasoline. Ethanol is almost identical to methanol when considering jet size. So jet it a little smaller than you would for straight methanol. Flattop 1 has the right answer just about double the jet. I would just guess somewhere around a 49 t0 51 would be a starting point. Anytime you hit the throttle and it just falls on it's face, Most likely not enough fuel.
 
I have the sudco book for the 28mm carb, where it talks about what each part does, and how it interacts with each other, but if the engine isn't set within specs, I guess tuning a carb doesn't much matter, I really wish some of yall lived closer to me. I sitting here poking it with a stick expecting it to do something, while yall can look at it say work, and boom it works flawlessly. I guess I just need to give up and concentrate on my son, who's motor is working great, with a stock appearing .690 from jrpw. I'm to the point of say for sale, I guess I feel defeated is all im saying...😮‍💨😥😞
 
Boomanchoo27 said:
I have the sudco book for the 28mm carb, where it talks about what each part does, and how it interacts with each other, but if the engine isn't set within specs, I guess tuning a carb doesn't much matter, I really wish some of yall lived closer to me. I sitting here poking it with a stick expecting it to do something, while yall can look at it say work, and boom it works flawlessly. I guess I just need to give up and concentrate on my son, who's motor is working great, with a stock appearing .690 from jrpw. I'm to the point of say for sale, I guess I feel defeated is all im saying...😮‍💨😥😞
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HAVE YOU TRIED ADDERAL?
 
DD83 said:
Focus daniel son..... one carb, one fuel, low speed, jet high speed jet you are making things way harder than they need to be.
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I understand that, the low speed I think I have figured out in the mikuni is a 12.5 idles perfect, just need to focus on the others
 
^^^ this . It shouldn't be this hard . Leave the air cleaner on , as it affects things . Part throttle is going to be kinda shakey as your only in that range for mili seconds . Get the low where it takes throttle. Then run it under load . If it burbles or shuts off at top rpm its likely too rich .
Put the neddle clip in the middle and leave it alone .
Too lean they tend too cough out the carb . Set your valves at say 002 - .003 leave them alone till you get it tuned . Double check ignition timing .
Make a list and stick too it .
Good thing is your sons is fine . Two sets of problems is much worse .
 
flattop1 said:
^^^ this . It shouldn't be this hard . Leave the air cleaner on , as it affects things . Part throttle is going to be kinda shakey as your only in that range for mili seconds . Get the low where it takes throttle. Then run it under load . If it burbles or shuts off at top rpm its likely too rich .
Put the neddle clip in the middle and leave it alone .
Too lean they tend too cough out the carb . Set your valves at say 002 - .003 leave them alone till you get it tuned . Double check ignition timing .
Make a list and stick too it .
Good thing is your sons is fine . Two sets of problems is much worse .
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Yea tell me about it. Just gotta work on gearing for him. I will double check everything again and try again.
 
Boomanchoo27 said:
Yea tell me about it. Just gotta work on gearing for him. I will double check everything again and try again.
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12.5 sounds lean when you crack the throttle with the air cleaner on is it responsive? if it coughs out the carb go up a size if it's responsive keep it and start to tune your high speed under a load.
 
DD83 said:
12.5 sounds lean when you crack the throttle with the air cleaner on is it responsive? if it coughs out the carb go up a size if it's responsive keep it and start to tune your high speed under a load.
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When I Crack the throttle it dies and very sluggish mid to wot, will do that on Friday and report back.
 
So guys, I didn't do this but my bro in law did today while he was off. I told him about the break, apparently he didn't listen to me.
He also said...
"So the adjusting screw on the exhaust rocker had backed completely out.. it was laying beside the push rod.. idk what kept it from falling down the tube but it didn’t.. readjusted valves.. fired right up.. so now I feel like the mikuni may work because if you think about it it has gotten progressively worse.. like I could barely keep it running with my carb.. screw was backing out slowly.. completely explains why it would rev once and then bog .. it wasn’t getting all the exhaust out"
 
Well thats a plus . Full transparency i changed three drop cord ends on two cords . Only to find the one i assumed fit , didn't
 
E85 could be (is in drag racing) a decent racing fuel. Definitely different tuning than regular unleaded (closer to methanol.)

Biggest problem will be that E85 at a pump is a range of ethanol %'s, not the 85% that is implied. It could be 75% one week, 83% the next, etc. That is the biggest reason I wouldn't recommend it as a racing fuel in carb applications (yet.)
 
tbyji2 said:
E85 could be (is in drag racing) a decent racing fuel. Definitely different tuning than regular unleaded (closer to methanol.)

Biggest problem will be that E85 at a pump is a range of ethanol %'s, not the 85% that is implied. It could be 75% one week, 83% the next, etc. That is the biggest reason I wouldn't recommend it as a racing fuel in carb applications (yet.)
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No longer using e85, we were buying it by the 5 gal bucket from sunoco, I'm using 93 octane as of now
 
Ok so I put the mikuni back on motor, changed to a 100 jet and 17.5 slow to start with, either I have no idea what I'm doing after reading all these posts or the carb just isn't going to work, let it get up to temp, stabilize on the low jet, pull plug and it's wet. Didn't go above a 110 on the main and it's still wet. Dropped needle down to the #4 and moved needle to the #2 position, pull plug still wet. Went back to the nibbi and no issues...🤞
 
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