hiya folks, as many of you may know, my old engine gave up the ghost, when i took the carbs of today theres flakes of metal on number 2 cylinder inlet, and on the exhaust port aswell, and when i took the plug out, there wasnt any left.
but anyways, after lots of phone calls all over the country ive managed to aquire an engine, had to drive half way across the country to get it though. i specified a good runner to partfinder ,its only done 29k as aposed to my old engine that had done 40k.
i started this morning, dropped the old engine out, and chucked the new one in, and put it all back together, the engine seems clean though i havent a clue how long it had been stood.
im using the same coils and carbs and everything off my bike, just changed the engine.
i didnt have any brand new plugs to hand but the ones in my old engine are 2months old so ive put them in.
the engine is turning over, and you can hear it just trying to do something, it splutters a bit and have had a couple of backfires, but shes not starting. could it be that my timing is out or something like that?
thanks, josh.

1. Check all connectors.
2. Check fuel pump working
3. Check you have fuel in carburetor
4. I would recommend to clear sparks to be sure.
5. Check fuse
6. Removed one spark from and connect to spark plug connector and lean it to frame - and start engine. If everything fine you have to see blue ignition spark.

Backfires? Check you've got the coils on the right cylinders. Even when I have big labels on my plug caps I still manage to get it wrong when I'm doing it in a hurry.

Have you checked all 4 plugs are sparking? Take one plug out and check each coil/lead.

as greggo said, mine sounded like that and it was the plug leads that were on wrong but when put right it started straight away.

hiya folks, just as a little update, turns out the pulgs were duff. and there was loads of oil in the cylinders, which i thnk was beacuse of the way it must have been stored, ive wacked some new plugs in it, and it fired up first time, ive also numberd my plugs leads alot clearer than they were. :-). there was alot of smoke coming from the exhaust at first, i think that was the oil in the cylinders burning off, and crikey, there was alot of smoke, but its cleared now :-). im gunna get the carbs balanced at the weekend to beacuse there all over the place. the bottom end doesnt sound to pretty though, ive notices a bit of whistling, so i think there may be a bearing worn somwhere? and second gear sounds absolutley dog awefull. its pulls through the gear but theres an awefull sound on the revolutions of the engine when in second, it selects ok, and pulls ok, it just doesnt sound healhy at all. all the other gears select fine and sound fine and pull ok. now, on my old engine i had the crack re-shelled and the gearbox was fine, so i mite swop them over?. the only thing is its my main mode of transport so im going to have to find time to do it. any ideas what could be up with that gear?

I'm going to guess your second gear noise is probably the hardening having been chipped off the gear teeth, and the gears having a rough surface. You would feel it through the bike under motion and hear it as it wouldn't be a smooth engagement of the teeth as it rotates.

Not sure how long the oil has been in there, but i'd be looking for metal filings or a shiney 'sand' in the oil and oil filter.

If you have a solid bottom end sitting around (sounds like a mother in law) i'd consider putting it in.

yer that sounds about right to be fair, the bottom end doesnt sound to great to be honest, my old engine felt a little 'smoother'. just got to find some time to do it to be honest.

just done a compression test on the old girl. numbers 1,3 and for a blowing at about 190psi which is great, but number 2 was only blowing 75. i did a compression test because the more the carbs were balanced, the more it didnt like it, so first i checked the carb rubbers for cracks, but they were fine, so i did the compression test. I have now dropped the engine out and gave it to my mechanic. ah well, im hoping its just a sticky valve, which i bet it is, i havent a clue how long that engine was standing round for. i will keep you posted folks, oh, just another point, are there any other forks to fit these yokes? and i seen graem france's ariticle on the nc29 in performance bikes, Nice job :-).

cbr_veze wrote:and i seen graem france's ariticle on the nc29 in performance bikes, Nice job :-).

Ooh, any chance of a scan?

yeah man, i will sort it out 2morow :-)