I want to pull the carb - my sputtering is back. I pulled the spark plugs and they were completely black, the truck stinks of gas when it runs, and the intake area once I pulled it off was wet. I'm almost 100% that my truck is running way too rich. Best way to fix this? I have no idea.... I pulled only the top off and cleaned the vacuum piston, needle etc.. but it looked relatively clean. (My truck has very low mileage. I think this is either a vacuum tube issue/or choke is sticking like oldmachinist commented on a while back). Only this time none of my tricks worked. I sprayed a ton of carb cleaner and that didn't do a thing. I tried using 94 octane, and added fuel drugs to the truck.. but no improvements. I would like to pull the carb, disassemble, and clean and check the float level. I've never done any work on a carb before.. so I'm only worried about ruining a gasket when I pull it. I have the english service manual, but it doesn't mention exactly what screws to pull in what order.. any help? Thanks guys. :frustration:
you can search the forum and find where old machine gave a great discription for the disassembly. It really isnt that difficult to remove the carb though. I will say that mine was very dirty and has run much better since, but on the driver side of the motor mounted to the carb is a bowl that coolant comes in to heat the carb. I wished I had not removed this. The O ring expanded about twice its size, tried another O ring a little thicker and broke the part. And so far my repairs have held and cant find a replacement. But good luck
I did a little write up on removing the Honda carb awhile back here's a link http://www.minitrucktalk.com/showthread.php?t=5752&highlight=carb+removal Your problem still sounds like it the choke not opening. Before removing the carb check the choke pull off with a hand vacumm pump to see if its working. If thats working alright then pull the two coolant lines off the right front side of the carb and make sure the coolant passages aren't clogged up. If you need more specific instructions on how to do these tests let me know.
I had actually removed the 3 screws from the top of that black thing and it stayed compressed until i forced it open with my fingers. When I put it back again it sucked out the air and I could see some levers move to a maximum position (i'm guessing moving the butterfly). Would this be sufficient a test? I do not have a hand pump yet.. if not, I could understand it may still have a leak if it doesn't seal the airways completely. (photo attached)
Describing pictures and the arrows within them: 1. i'm supposed to test this line for suction? If so, I took it off the black thing with 3 screws and then I sucked/blew into it and I can hear a bubbling coming from somewhere. 2. Spring seems totally fine.. This is the area in which I'm sure gets suction and pulls the diaphram up.. how much suction I'm not sure. 3. Diaphram looks in good shape, but I was easily able to pull it off (gently). Not sure if that's supposed to be a complete seal that's greased or wet? 4. Coolant line appears totally fluid and clear of obstruction. 5. Same as #4. 6. I took this off and found the needle is a bit loose, is that normal? 7. These are the levers i'm talking about that move when I take off #1 when engine is running, and they move again when I press down on the black thing to create proper suction in the diaphram. 8. I took this off and the engine revved like mad.. no idea what it does. It is somewhat cracked but might not be an issue since the cracking is on the other side of the clamp. I checked most of those suction lines and they appear all in perfect shape. This truck barely has any KM on it.
You suppose to put vacuum on the line going to the assembled black choke pull off and see if it pulls the linkage up and holds it there. You need to check for blockage of the part where the coolant lines hook. Coolant has to flow thru the part to heat it up and that's what pulls the choke the rest of the way open. The engine reved up when you pulled the line off the intake manifold because the engine was getting more air.
I see - yes, this is what I show as #7 arrow.. It does pull the linkage so the vacuum seems to be good. This does appear to be clear - however I'm not 100%. When I pulled each of the tubes off coolant flowed freely in and out of the carb section (kinda like your toilet bowl water moves on a really windy day). ahh I see.. it still did it's sputtering thing even with the revs. I guess I'm at a loss unless I pull the carb.. I had a look at your other post. I think I'd be ok with it. I just don't want to break a gasket or anything.
On second read I missed the part about holding it there. I will attempt the vacuum on the line and if I understand you correctly I just need to suction once and if there is a leak it will return the choke back to the original position until I reapply suction
When you put vacuum on the choke pull off it should pull the linkage up and if the diaphragm is good it should stay until you release the vacuum. In the picture below I've pulled 15 inches of vacuum on it and it is staying that way.
I finally picked up a vaccum tester and hopefully will try it tonight.. I'll let you know the results. I also drove out to Costco and was revving the crap outta my engine and it seems to feel a bit peppier and feel more 'normal'. Still was trying to stall out though, I was glad I didn't get stuck on the side of the road! Does anyone know what the labelled band range ---1---, ------2------, -----------3------------ are labelled on the speedo? Is that telling you that first gear range is 0-20km, 2nd gear 20-45km, 3rd gear 45-75km? If that's true, I've been short-shifting my truck pretty badly. Might explain *some* of the carbon build up.
Hi OldMachinist.. got me shiny new vacuum tester and put it on the carb.. pulled 15inches and... it stayed there! Now what?
Next you're going to have to see if the rest of the choke system is working. With the engine and top carb cover off start the engine cold, watch the choke linkage as it warms up. The device where the coolant lines hook to the carb should warm up and push the choke the rest of the way open.
The coolant does appear to push the the choke towards being open.. but i'm not sure if it's ALL the way. There is a metal flange that slowly creeps towards the white plastic and then starts pushing the white plastic thing.. but it doesn't look like it goes all the way to MAX. However, using my hands i forced it to be maximum and the truck didn't do anything different. (and the gear that obviously is attached to the coolant heating up part moves to its max). so It *appears* that if if force my truck to have the choke wide open it doesn't change the truck engine sounds one bit. It it still sputtering and revving in a yo-yo like fashion. What I mean by that is the RPMS fluctuate up and down all the time. The sputtering happens at all RPM levels.
Update: coolant does pull the choke all the way. 100% I just didn't let the truck warm up enough. I did notice that I have vacuum at idle on the distributor vacuum test... but I doubt that's related to this. It's ony about 5 inches of vacuum.
Well I thought for sure it was a choke problem. The next thing to look for is a vacuum leak. Try spraying each vaccum line with some carb cleaner along their entire length if the idle changes you've found the area with a leak.
How do i know which lines are 'vacuum' lines.. is it all the ones that are the same size? Please excuse my non-mechanical know how
Ok - so I practically emptied my carb cleaner over every line I could see.. I could not detect any difference in the idle whatsoever.
All the rubber hoses going to the carb and intake manifold are vacuum lines execpt the 2 coolant lines and the 1 fuel line. Not all of them will have vacuum on them at idle but you can't hurt anything by spraying them. Also spray the flange area where the carb mounts to the intake manifold in case its leaking there.
Ok - in fact I did run out.. heading out to the store to get another can to hit up the flange.. every other hose didn't work. Back in a flash.
You originally described it as smelling of fuel and fouled spark plugs so it really sounds like a carb problem. Have you checked and replaced the air filter recently? It may have gotten soaked with fuel and is now clogged. Try running it briefly without the filter and see if its better.
I ran it without the entire intake assembly off by removing the clamp and exposing the metal grille on the carb. Still no different. I did inspect the filter, it looks yellow. I haven't tried removing just the filter tho.. I'll do that now. I know the plugs are black all around, I haven't replaced them at all - and my exhaust tip is coated black. My oil pan leaks (or seal is broken) and I get low on oil over a couple seasons. Either she's burning oil (no there's no smoke that I can see) or she's leaking it. Possibly another issue.
On second inspection.. i pulled the plugs.. what do you make of them? I'm a bit concerned about the yellowing of the porcelain.
I wouldn't worry about the yellowing they all look that way after awhile. Somthing is going on with the cylinder that the plug in picture #4 came out from. I can't tell if its oil or gas fouled from the picture.
They are all kinda like that. I had rubbed the other plugs trying to clean them. #4 is the way they look without me cleaning them. I'm still sure is running rich given the gas smell and black sooty tailpipe. At this point is there anything else I can do without pulling the carb?
I think you're at the point of having to pull the carb. Mark all the vacuum lines before removing. I suggest you go slow and take lots of reference pictures. Be careful taking the carb apart because the only source I've found for new gaskets in from Japan. Good Luck
Ok - there is a guy in town here that does JDM part importing.. however I've never bought anything off him so I'll have to be careful.
