Hanging rev 250r air cooled passed leak down test

[barnett468]

Yes I will perform more tests and get back to you guys. Yes my petcock is clean.....and yes that was funny (mixed fuel joke) I'm not against you guys or trying to piss you all off. I am working on these tests but I do feel the need to comment back whenever someone asks me something I will meSs around with it today and see what happens.

Just some trivia. Imo, it is better to start with a super rich main on a bike that is new to you irregardless of how it runs. The reason is that it might have been jetted too lean by the previous owner and/or it might have been jetted properly but for warmer conditions and/or higher elevations and if you live near sea level and/or where it is much colder than where it might have come from etc.,it will be lean and might be lean enough to cause it to seize. This is the same if you have a new engine but performed high perf mods too it during the rebuild.


PLUG CHOP - You do NOT want to do this on any bike that you are unfamiliar with. The reason for this is, if it happens too be too lean, it might seize during the wot plug chop run. If this occurs, it would be unnecessary to do a plug reading.

This actually happened to someone on the site around 6 months ago. I asked him why he did that and he said a mechanic told him to.



It must have been a HONDA mechanic! Ahhhh, ha ha...

[El Camexican]

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. . .

I don't know who did it but someone cleaned the bejesus out of this one!

Keep in mind it's spelt "petcock" and not "pet cock" which as we all know operate best if polished regularly

[El Camexican]

I know this is as half assed a way to determine a main jet as there is, but I’ll throw it out there anyway. I believe the 250 Tri Z came with a similar Mikuni carb and a 470, or 480 main. It that’s true I would think you would want to start with at least a 450 main on your Honda and if need be work your way down.

[barnett468]

Keep in mind it's spelt "petcock" and not "pet cock" which as we all know operate best if polished regularly

Hey...give me a break...isn't it enough that I'm a pig that talks and now you want me to read well too. Why don't you just BITE MY BACON!.


Holy crap...pig..bacon....polish..pet...

[barnett468]

I know this is as half assed a way to determine a main jet as there is, but I’ll throw it out there anyway. I believe the 250 Tri Z came with a similar Mikuni carb and a 470, or 480 main. It that’s true I would think you would want to start with at least a 450 main on your Honda and if need be work your way down.

Hey...that's not as half assed as the way we've been doin things!


Holy cr_p!

[DohcBikes]

I know this is as half assed a way to determine a main jet as there is, but I’ll throw it out there anyway. I believe the 250 Tri Z came with a similar Mikuni carb and a 470, or 480 main. It that’s true I would think you would want to start with at least a 450 main on your Honda and if need be work your way down.

There we go.

Only thing i would add is why not a 480 first but anything up in this range is gonna at least give an indication. As barnett mentioned, I like to start way rich and lean it out till its happy.

Again, we're very focused on the main jet here, but dont overlook some pilot jet tuning! Process of elimination at the very least.

[knipfeldustin]

It's been awhile but the death rev has finally been fixed!! I tried so many different things and tore into the top and bottom ends, new gaskets, different fuel octanes, carb settings and little hondabond along the way. All of this was to no avail. We even had this thing continue running for a few seconds after pulling the plug wire off (explain that?) but anyways finally borrowed a different carb and thumb throttle setup from a friend of mine and its running like a champ, no death rev, very responsive and pretty damn fast. I still have no clue as to how this was caused by my old carb or why but its fixed now and I'm happy.... Learned along the way it has pretty aggressive porting and has a .060 over bore (piston says 1.5mm 431p6 cd) appears to be a fairly fresh top end. Crank seals ended up being good when I checked them also. I should have just tried a different carb a long time ago but never thought it would be that easy. Just thought I'd share with you guys what all i found out and I appreciate the help along the way.

[nicker71]

I've said it was probably that old POS mikuni carb that was on it. And I was right!!