BenP

hi all, here with yet another problem I am now on my third engine with this bike :/ as the first one went bang as the big end bearing went then second time with the oil pump packing up unfortunately anyway im having a problem starting the bike even when its warm, everything is spot on ive checked it all over, however it just dosent like to start, i have a feeling that its something to do with the coil, reasons being as its still the original from 1991, so i think it may be breaking down, also i was wondering if any one knows the colour the spark is meant to be, as i have a feeling its not very strong, the spark is coming out as a pinky colour and dosent sound very aggressive. also could the weak spark cause lack of power at high revs as anything above 8500 rpm the bike stutters like its fuel exhausted. if anyone has any idea what may cause the bike to not start up well i would much appreciate it may i add it does start up after 10 kicks or so the last engines always started up first or second kick, the plugs the correct one. Ben.

I have now eliminated all the things you have said about turns out there was dirt in the carb however it didn't sort the problem I also decided to change the stator plate so I put my original one in from my last engine and still no difference so I'm really running out of options so my last guess is. Could it be the crank seal letting in air disturbing the fuel/air mixture ratios at high rpm?

Out of curiosity could it be anything to do with the stator plate/coil??

Thanks very much for the help I checked the plug and it was a nice Brown so I'll do the following of which you have stated and I'll let you know how I get on thanks again

Yes it is the original carb and when I say pop the big end bearing went causing the debris to go up into the barrel destroying the piston the crank was mullered etc so I just decided to buy another engine

Hi all sorry about yet another post. I have a 1991 dtr 125 and just put a 1998 engine in it as mines went pop Anyway I got it all up and running but after letting it wear in blah blah blah I thought I would cane it just to check it was all running as it should however after 8500 rpm the bike acts as if it's starved from fuel or something it keeps slowing down then picking up speed again but won't go any faster so I thought this could be the reeds so I changed them to boysen carbon reeds as the ones I took out were very worn now after putting the carbon reeds in it hasn't made any difference apart from throttle responce so I'm wondering if it could be an electronic problem? But I can't see how has its still running on the 1991 electrics and the other engine was fine but ever since putting this 1998 engine it just won't rev high If anyone has any ideas I would highly appreciate it

Hi guys sorry about yet another question but I'm having big problems trying to find any engines for my 1991 and was wondering if any of you know if the 2003 dtr engines would be okay to fit in my bike with little problems? There are many 2006 RE engines but I''ve heard that would be a bit tricky to fit onto my bike due to the electrics? Any help would be much appreciated Ben.

Okay cheers for that! Do you reckon I should contact Yamaha to get me an engine as I would like it asap or do you reckon it will be ridiculously expensive?

Hi all I've got a bit of a problemo yesterday my engine decidied to go bang as the big end bearing self destructed ruining a lot of the engine including piston barrel head and a lot of scoring in the bottom of the engine. Anyway I'm looking for new engines and struggling to find any engines for my model however there seems to be a lot of dt 125 re engines kicking around and was won dering if they would fit in my 1991 frame?

Just out of curiosity recently my engine went bang as my big end bearing broke shattering the piston and damaging to much to fix so I've been looking for new engines and was wondering if a 2006 re engine would fit into the frame of a dt 125 r 1991 model

Okay cheers for that!! Saves me being bored having to change gear at 5000 rpm!

I've recently had the barrel rebored, head skimmed and a new piston fitted and was wondering how many miles I should do before I can take up the revs as at the moment I've done 200 miles and have been changing gear and 5000 rpm and not going over This is for a dt 125 r

One more thing just to double check I recently had the barrel rebored and a new piston put in 100 miles ago roughly. How many miles should I be taking it easy for i've been told I should aim for a round 500 miles then start to rev it more and more as at the moment I'm changing gear around 5000 rpm

Cheers for the help guys, it turns out that head was warped so getting it skimmed today then putting a Yamaha gasket on and hopefully that will seal the deal

Thank you very much! I'll order up a Yamaha head gasket now!