Big Red 250es Dies at WOT

[ps2fixer]

I have several 250es big reds that run well, but if you floor it at near idle, it acts as if you turned off the key. If I rev it slightly then floor it, it runs fine. I'm guessing something is in the carbs causing the problems.

They are all bone stock of what I know, but the last owner said he combined something like 10 250es machines to make 4 complete and a 5th near complete. 3 of them have mocked up fenders and look bad and a couple were still in good shape but have other issues.

Background story on them: One of them I took apart the carb and cleaned it pretty well and it still had the same running issues, so I tried SeaFoam in it and after ~30 mins of running it, the carb started to run with out choke and could get into the higher revs a bit. Another 15 mins or so it got to the point I could ride it normal except for the issue above. Did this with one other that you could only start with full choke and have it idel for a few secs and die. It had the same results with the seafoam treatment with out taking the carb off. The last one I got it with the WOT issue and isn't used since it isn't complete (missing fenders, lights, etc) but has the cleanest engine of them all (no rust, looks to have been kepted in doors).

Anyway, thanks for any help on this issue.

[vonlindheim]

i'd put that clean motor in whatever rig you want to ride most. take your best carb and put it on the different motors to isolate if it is the carb that is the issue. i would also compare your best carbs inner workings with your worst. i've had guys put strange parts inside that are either junk, broke or not even the right fit. try using small wire to clean out passages and take your jets out and inspect/clean. keep trikin :)

[ps2fixer]

thanks for the details, I swapped a carb that didn't work well with the super clean engine to use it's carb on the other (since it is complete) and problem moved with the carbs. When I get some time I'll have to pull a working and a couple of the ones giving me problems apart to compare.

[WJG1000W]

do you have a broken or cracked intake manifold

[ps2fixer]

I didn't check, but I should since I had them crack on my 99 warrior and the TTR dirt bike. Thanks for the replys :).

Edit:

Just noticed my best runner does the same thing, maybe it is just a normal thing.