I used to (when cars and trucks had carbs) pull the jet and measure the opening with a drill bit, then either drill out to the next size up or solder the jet opening solid closed, and drill out the next size down, reinstall and see if I got the results I wanted. This is an easy way to fool around with jetting if you don't have the sizes you need lying around, or don't have time to order them, but the drills I used were about the sizes you'd use to clean cutting/welding torch ends. Just a thought.
2 Stroke 1988 CR250R Wont start / Wet Plug
- Thread starter Stringer
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I used to (when cars and trucks had carbs) pull the jet and measure the opening with a drill bit, then either drill out to the next size up or solder the jet opening solid closed, and drill out the next size down, reinstall and see if I got the results I wanted. This is an easy way to fool around with jetting if you don't have the sizes you need lying around, or don't have time to order them, but the drills I used were about the sizes you'd use to clean cutting/welding torch ends. Just a thought.
I like your ideA of starting with a plan. I didn't know about your original find on the float level. I think you are dead on about the former owner band aiding something. You may have been able to tell I have no appreciation for keihin pj carburetors. I don't. Before you take that one apart again, remove the choke plunger and confirm the sealing surface is good, that it isn't leaking air, and a needle exists on the downward end of it. Confirm that your power valves open as the revs climb.
Ok I will check out the choke and valves as you suggested and see what I can find, thanks! I didn't take the carb off yet anyway because it is getting too dark here. Hopefully I will have time tomorrow.
I did check out my transmission oil and new magnetic drain plug, let me know if this reveals anything. After the rebuild I put in 596cc's of belray gearsaver which is red, and a moose magnetic drain plug. I have about probably 40 minutes on this bike since the rebuild. The drained oil looks decent I suppose, definitely a darker red though. I drained out 540cc's, is this too much loss?? And here is what my plug looked like, lots of shavings in there. Is this alarming?
I drove the bike around a bit today. Nothing has changed. Easy to start, tons of hesitation, black oil out exhaust pipe, coupler, and black oil seeping from where pipe meets engine despite having a new gasket and sealing ring. I did also notice where the pipe meets the engine does not sit quite flush, even after trying to tweek mounts etc. The exhaust flange side with the springs sits flush, and the other end is about 1/8" from sitting flush. And if I operate kickstarter slowly with hand, it sounds like there is fluid in the cylinder. And my Radiator fluid was low maybe 2 or 3 ounces.
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If the coolant is not in the oil than its fine. Did you loose it or just not check it after the initial start up (air bubble). Trans oil is always stuck behind the bulkheads inside the engine. When I do and oil change I always crash the bike to one side and the other to make to oil get over the internal bulkheads and drain. Jetting, I'm not well versed but the guys have you going in the right direction.
How hard are you running this bike? Power valves not fully opening could cause some hesitation. I still don't hear any complaints on excessive or bad smelling exhaust fumes/smoke. I would tap this thing out 1st 2nd and 3rd gear a couple times and see what happens. Maybe posting a vid of how she runs would help.
Well I checked coolant level earlier as I was running it, and it looked a tad more full. Maybe because it was running the first time, and not the second? I am able to safely check the coolant after it's been running awhile. I am guessing because of the quality of coolant (evans waterless), new rads that claim 40% more capacity, and the bike is running so rich is doesn't get very hot. Just a theory.
Now that I have given it thought, I put in a slightly incorrect amount of oil. I had just finished getting the top end together, and manual stated after engine disassembly, use 0.63/qt (596cc's), otherwise use 0.58/qt (549cc's). I wasn't using my brain and now realize the manual was probably referring to bottom end disassembly which was not performed. Do you think this extra 47cc's of oil I put in was simply expelled through an overflow hose, or is this difference too small to matter entirely?
I have had no problems giving it WOT over and over, I have been running it hard since
One in awhile I can wheelie with it, but mostly not due to tons of hesitation. I peg the throttle often. It was smoking ALOT before I recently backed off the screw to 2.5 turns out. Many report best success with 1.5 turns out from what I've read. As far as smell I can't help there, I can hardly smell a thing :/ Smoke is white and seems like more an appropriate amount after going to 2.5 turns out, from two.
IT'S THE POWER VALVES
They are not moving and just collecting black oil. I was really afraid of this, because I have spent 80% of rebuilding this bike trying to get the valves right. There is just no information out there I haven't seen, or any tweeking or wrenching I have not done. I don't know what to do at this point, because I have tried it all and then some. And there is no known person who is familiar with this powervalve system. I am at a dead end at this point. The valves on this bike will just not work.
They are not moving and just collecting black oil. I was really afraid of this, because I have spent 80% of rebuilding this bike trying to get the valves right. There is just no information out there I haven't seen, or any tweeking or wrenching I have not done. I don't know what to do at this point, because I have tried it all and then some. And there is no known person who is familiar with this powervalve system. I am at a dead end at this point. The valves on this bike will just not work.
I think I am pretty familiar with them. I had mine down a few times and others, as well as with the somewhat similar 125's. I just never had any that didn't work before or after I disassembled them. I also have an original factory manual.
By the way, wet is far better than dry when talking about any power valve IMO.
By the way, wet is far better than dry when talking about any power valve IMO.
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Im wondering if your original factory manual gets more in depth than the Clymer in regards to this HPP system. Are you able to scan and send me the pages which reference the HPP?
I also did a google image search and came up with this. This is not how mine are set up. You see where I circled, the pinion shaft spring is under preload as you can see. Mine is not like that. I would imaging that would make it harder for the valves to open though? Does this picture look correct? Again the area circled is different than mine. My pinion shaft spring is not under load like that.
I am on iPhone today. Yours look as good as a small picture provides. If yours are getting no movement the first thing for me is open the covers and see and feel if you are getting something that is trying to move. There is a screw that acts as a plug. Down low on the cylinder where the rack is. Remove it and make sure it isn't too long. I am going to guess it is not the problem. But trying running the engine without it.
I think that judging by the former owner's band aid approach, indicated by jetting and float level that the problem us in the cases closer to the governor.
As frustrating as this is, do a little V dance for taking a critical look at the situation and not taking off like a ruptured duck towards the parts store for brass to lean out something once you determined that raw fuel in excess was pretty unlikely. My next step is to eliminate the things that increase vacuum and pull more fuel past the existing jets.
I can copy and fax. May be able to get someone to scan for me.
I think that judging by the former owner's band aid approach, indicated by jetting and float level that the problem us in the cases closer to the governor.
As frustrating as this is, do a little V dance for taking a critical look at the situation and not taking off like a ruptured duck towards the parts store for brass to lean out something once you determined that raw fuel in excess was pretty unlikely. My next step is to eliminate the things that increase vacuum and pull more fuel past the existing jets.
I can copy and fax. May be able to get someone to scan for me.