gingertom Posted July 17, 2011 Report Share Posted July 17, 2011 Hi all honda experts, I have a TLM 200 which i have just done a full engine rebuild on, main bearings main seals ect. It runs (somtimes)on a keihin pe26 and will currently not tick over for more than a few seconds and any aplication of throttle just kills the motor, the carb is all clean with fresh fuel at 50:1 the spark plug is a new ngk and has a visible spark. The confusing bit is it will start easily a few times and then cut out but after about the 5 or 6th go it will then not start again for the rest of the day This is rather disapointing after its been totally re-built at some cost and lots of time, i just want to use the thing now, any suggestions anybody............... Quote Link to comment Share on other sites More sharing options...
keychange Posted July 18, 2011 Report Share Posted July 18, 2011 Sounds like it is flooding (loading the engine with fuel. If you remove the plug is it wet? Try another plug - a plug that sparks outside the chamber may not spark inside the chamber. Did you fit the piston the correct way round? Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 18, 2011 Author Report Share Posted July 18, 2011 Thanks for your speedy reply, I shall try another plug tonight, as for the piston in the right way around, yes it is cut out facing towards the carb (rearwards) i did have this thought myself but quickly discounted it. Any other suggestions appreciated. I Was thinking of trying a new cdi unit for a bigger spark, i was thinking as more fuel goes in the motor could this extinguish the spark if too much fuel present...........just a thought what does anyone think.....as a last ditch effort can anyone suggest a decent motorcycle engineer in lincolnshire....not a dealer though. cheers jimm Quote Link to comment Share on other sites More sharing options...
bashplate Posted July 19, 2011 Report Share Posted July 19, 2011 could the coil be braking down when it gets hot? same for the cdi unit. Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 19, 2011 Author Report Share Posted July 19, 2011 could the coil be braking down when it gets hot? same for the cdi unit. I don't think the coil has time to get hot as it only runs for a few seconds at a time, i did all the electrical resistance checks on the coil last night and all came up good. The cdi resistance checks are a little more tricky as it says in the manual to use a certain type of tester a SANWA T/N 07411-0020000 or a KOWA DIGITAL TASTER T/N 07411-0020000. I only have an AVO 8 or pocket sized multimeter (modern)i wonder if you really neeed the ones they say as modern technology has come on leaps and bounds since the 1980's. Quote Link to comment Share on other sites More sharing options...
keychange Posted July 19, 2011 Report Share Posted July 19, 2011 could the coil be braking down when it gets hot? same for the cdi unit. Doesn't sound like it has a chance to get hot and as he says it then won't start for the rest of the day. When this next happens turn fuel off and remove the plug - then kick the bike over and check if fuel mix is being pumped out of the plug hole - if so it is flooding and loading the engine chamber with fuel - if so check your float level and make sure the the needle seat is blocking fuel when the chamber is full - from memory the Mikuni float level should be set using measurements upside down ( do a google search Mikuni float level) but you can test if the seat is sealing off the flow by working the float and either gently blowing through the fuel line or allowing fuel to flow through Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 19, 2011 Author Report Share Posted July 19, 2011 Doesn't sound like it has a chance to get hot and as he says it then won't start for the rest of the day. When this next happens turn fuel off and remove the plug - then kick the bike over and check if fuel mix is being pumped out of the plug hole - if so it is flooding and loading the engine chamber with fuel - if so check your float level and make sure the the needle seat is blocking fuel when the chamber is full - from memory the Mikuni float level should be set using measurements upside down ( do a google search Mikuni float level) but you can test if the seat is sealing off the flow by working the float and either gently blowing through the fuel line or allowing fuel to flow through This sounds like a good diagnosis, just to clarify when you say "make sure the the needle seat is blocking fuel when the chamber is full" you are talking about the float bowl/chamber being full and not the engine chamber, your diagnosis seems to make sense as we all know a flooded crank case/engine chamber will not help in the starting of the motor.I will do what you have suggested some time this week and post the results on here.....again Thanks for everyones responses..jim Quote Link to comment Share on other sites More sharing options...
keychange Posted July 19, 2011 Report Share Posted July 19, 2011 you are talking about the float bowl/chamber being full Yes correct I am talking about the float bowl - if your carbie is flooding and/or your fuel tap isn't turned off correctly the engine chamber could be loaded with fuel - first kick with a dry plug and it might splutter but as soon as you open it up it will die and stay dead until it dries out. Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 22, 2011 Author Report Share Posted July 22, 2011 I checked the float valve is doing its job and unfortunatley (for me ) it is, it cuts of the fuel supply when the float is at 19mm. This is the correct height from the manual. At a loss as to what to do next now has anyone else got any suggestions.........jimm Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 22, 2011 Author Report Share Posted July 22, 2011 I checked the float valve is doing its job and unfortunatley (for me ) it is, it cuts of the fuel supply when the float is at 19mm. This is the correct height from the manual. At a loss as to what to do next now has anyone else got any suggestions.........jimm Yes and the needle blocks fuel when throttle is shut.......boooooo Quote Link to comment Share on other sites More sharing options...
keychange Posted July 22, 2011 Report Share Posted July 22, 2011 Yes and the needle blocks fuel when throttle is shut.......boooooo You didn't reply on the "remove plug and check if wet" - yes please still do that. Otherwise - now check for leaks between carbie and inlet - there are many ways to do this some people spray water, other spray fuel or LGP gas - whatever you use you are listening for a change in engine revs. Finally see if you can borrow a CDI and see how that works - do this last as CDI's are not cheap Quote Link to comment Share on other sites More sharing options...
gazza Posted July 23, 2011 Report Share Posted July 23, 2011 A couple more things to check, Check the fuel flow through the tap with the petrol cap on and off the tank Check that the spring clip ( not the circlip) holding the needle in the carby slide is fitted correctly and not allowing the needle to "hang" when the throtle is returned to idle cheers Gazza Quote Link to comment Share on other sites More sharing options...
bigmike1961 Posted July 24, 2011 Report Share Posted July 24, 2011 When it won't go after the 6th kick is there still a spark? (cdi good) Is the wiring all in good condition? ( once had terrible trouble with an XL185 engine because the pulse generator wire was worn.) What is the plug like - wet with fuel or dry? ( over rich mixture ) What happens if you turn the fuel off, take the plug out & spin the engine over to clear any excess fuel? Will it start again? In the opposite direction:- Is fuel actually getting to the carb in sufficient quantities? (blocked fuel line, filter or fuel tap) Take the fuel lie off the carb and make sure the fuel floods out with the fuel tap open. Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 25, 2011 Author Report Share Posted July 25, 2011 You didn't reply on the "remove plug and check if wet" - yes please still do that. Otherwise - now check for leaks between carbie and inlet - there are many ways to do this some people spray water, other spray fuel or LGP gas - whatever you use you are listening for a change in engine revs. Finally see if you can borrow a CDI and see how that works - do this last as CDI's are not cheap yes to plug being wet, as for spraying water /fuel between carb and motor i can't do this because it does not run for long enough 3-4 seconds currently. Thanks for the reply Quote Link to comment Share on other sites More sharing options...
gingertom Posted July 25, 2011 Author Report Share Posted July 25, 2011 When it won't go after the 6th kick is there still a spark? (cdi good) Is the wiring all in good condition? ( once had terrible trouble with an XL185 engine because the pulse generator wire was worn.) What is the plug like - wet with fuel or dry? ( over rich mixture ) What happens if you turn the fuel off, take the plug out & spin the engine over to clear any excess fuel? Will it start again? In the opposite direction:- Is fuel actually getting to the carb in sufficient quantities? (blocked fuel line, filter or fuel tap) Take the fuel lie off the carb and make sure the fuel floods out with the fuel tap open. Yes to fuel getting through, iv'e emptied the tank and flushed out with fresh fuel, done all the wiring checks stated in the manual, primary and secondary coil pulse generator and generator coils. Plug is always wet, yes to still a good spark even when it won't fire..............thanks for your ideas keep them coming..jimm Quote Link to comment Share on other sites More sharing options...
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