Hey guys need some advice with my 1999 mc22 i just got . Main problem I'm having is the RPM hangs when you twist the throttle. Yesterday i rebuilt the carbs and set the pilots to 2 and 1/2 turns they were set much higher than that, has fresh plugs new z92 fuel filter new fuel lines (7.9mm) changed fluids when i first started it up it was running perfect, i snapped the throttle and the RPM came back down nice and quick back to 1500RPM, i let it warm took it down the block and it started to die . I dont have a right angle screw driver so cant just adjust the screws without pulling them out so was hoping to get some advice on what to do next i made a quick video sorry its sideways ]
Sound's like it's too lean, and wasn't tuned when it was at operating temperature ? Did you take it for a ride before trying to tune it ?
Try and set the screws to where they were before. I've had cases where the Honda settings aren't quite right anymore on older bikes. With that said, on my 91 MC22 the stock settings were perfect. My tips would be use a water bottle and hose a small fuel tank for easy removal and make sure you have the main jets correct (the outer and inner one are different). Make sure the throttle is snappy. And make sure the carbs are balanced properly. Otherwise you'll just have to do some trial and error. I would give it some more revs though as my MC22 never ran properly if you just revved it under 10k. Also, double check the vaccum hose is good. I had an issue once - I just chopped the hardened end of the hose off and she was good to go. They're supposed to have small clamps but my bike never had them / needed them.
From my experience the MC22's never did quite agree with a fuel filter. Being gravity feed they didn't flow enough through an extra filter as they have a mesh screen over the pick up for fuel tap. Try removing z92 filter and see if it makes a difference. Fuel tap diaphragms are also prone to stop working properly.
Is it one of those opaque plastic ryco filters? I never could get fuel through them even on my FZR250 with a fuel pump. They are designed for cars with higher pressure fuel systems. I use the supercheap auto SC4F filter in place of the ryco ones, it behaves with gravity/vacuum feed systems, but it's a bit bulky. Have yet to find a smaller alternative.
Yep. Ditch the filter. No value whatsoever. The gauze screen in the tank (assuming it is still there) is adequate. However, check that it is not the issue. Make sure you have fuel in the tank (plenty) and the tap is on. suck on the vacuum tube for the petcock valve with the main fuel line disconnected. Fuel should flow freely out of the tap. I would also be looking for air leaks in the induction system. Check that the carb boots are sealing correctly. These are not that expensive to replace. I purchased a set on ebay recently for about $40. Peter.
I have never heard of someone so against fuel filter's ? especially when they are fitted from the factory along with a strainer in the tank, and sometime's another strainer on the needle and seat inlet It make's sense to have a secondary filter. I have seen plenty of dirt get through those factory plastic fuel pick up strainer's/filter's in the bottom of a tank, this was in my FZR fuel bowl's when i bought it I'd rather it didn't go through my carby and engine causing problem's
That is some horrible dirt. Yes I am going on a bit like a broken record. You will note that this post is about an MC22. As far as I am aware the MC22's have a gravity fed fuel system and do not have a filter as standard. Both my 92 and 98 MC22s do not have filters. The fuel bowls on both do not have the level of sediment that you have found. I think some of the earlier model CBR250s (MC19???) have a pump and also have a filter. Don't get me wrong. It is not that I am against filters. It is just that slapping one in on a system not designed for one is likely to result in more issues than solutions. The primary purpose here is to help Brett track down his problems. Sorry for offending.
Have you checked that the fuel tap is supplying enough fuel? Try taking the fuel vacuum tube off the carby or manifold and the fuel line, hang the fuel line into a jar or tin Turn the tap to the on position and suck on the vacuum tube, fuel should flow freely out the fuel line. If it seem's restricted you might want to drain your tank and remove the tap from the bottom and check it out, could be blocked or the mesh filter's may be blocked ?
Dirt ruins engines and gets in three ways. 1; at assembly (dirty tools or workspace) 2; no or sub standard air cleaners (eg pod filters) 3; dirty fuel (from rusty tanks/drums or bowsers) I agree that the feed problem needs to be sorted first, but when fixed a good flowing filter will be essential to long engine life. MC-19 has a pump after the filter (if it was before the filter it would fill the pump with crap and stuff it reducing flow), but does not the MC-22 have a prime setting on the fuel tap? If set to prime then fuel should flow freely to the carbs. If no flow then a look at the screen inside the tank will be required. I run a filter of the biggest size I can fit in all my bikes. The extra capacity of the filter has sometimes been a help in WOT situations where the flow from the tap is just enough to feed the engine.
I have managed to get the bike to running condition still needs a tune but it runs well, the petcock is damaged the knob is snapped off so removing the tank can get messy, sometimes i pull it off and fuel wont flow out of the tap other times it just pours out then i just open up the tap and it will hold petrol again in have ordered one almost 2 weeks ago from china as well as some carb boots i also got new grips and levers at the same time and only took 5 days to get here really happy for 30 bucks. Sent from my SM-G900I using Tapatalk
This is the fuel filter i replaced with the z92 Has a 4mm id on one side and a 6mm id on the other Sent from my SM-G900I using Tapatalk
Good to hear. For the future reference of others, I have attached some images of a petcock valve assembly and in-tank fuel filter removed from one of my MC22 bikes. This filter looks clean enough but will not flow fuel. I replaced it and the fuel flow problem was solved. The point I am trying to make is that you only need a minimal obstruction in the fuel supply line to cause issues on these bikes.
That filter is far too small for a 250cc. That would even restrict the flow on a lawn mower. I have one of those taps (new, doesn't fit MC-19) here if you want it.
