July 17, 201412 yr Hi all a bit of advice required please. Re 2002 Montesa 315r. PHBL26BS Bought Bike then stripped it straight away as I wanted a good one as getting back into trials after a long time, so done all bearings etc. Just had engine re built ie. new piston,rings,mains,seals and cylinder re-plated. The thing is I cant seem to get it running rite at slow revs, But starts 1st kick, Symtoms are..... 1) Doesnt idle well, 2) Air/Fuel screw doesnt seem to do much, 3)Off choke its not picking up sharply, 4)If you rev it a bit sometimes the revs just go up and up and have to stall it with back brake. Please note.... Throttle cable free and lubed, slide snaps shut and free, slide shows no sign of ware. carb has been stripped cleaned and jets have been cleaned with solvent and compressed air. Needle clip=3rd from top. The jets are main=110, slow=33 Had a look at manual and it says main=110 slow=35 Could this slow jet be causing the problem ? being a smaller number ? If I cant sort its going in to a shop (anyone recomend one in Bolton/Bury area?) as I want to start riding it !!!! Thanks in advance. Craig.
July 17, 201412 yr If you are looking for a good mechanic try Geoff who works at Sandiford Off Road in Burnley BB11 5SS 01282 455 697 about 20mins from Bury on the way to Clivinger practice venue. Good luck.
July 17, 201412 yr The difference in size shouldnt cause the problem you have it sounds like its blocked especially if adjusting has no efect
July 17, 201412 yr Didn't these bikes have two slow jets? Look up where you took your slow jet out and see if there's another one up there.
July 17, 201412 yr i thought that aswell like a mid range jet or inbetween ,, it is a dellorto isnt it ?
July 17, 201412 yr As jer says, my 315 had two pilot jets. One was well hidden if I recall, been a while since I owned it.
July 17, 201412 yr Author No I think its only one as its the later delorto, am going to have one last go at sorting it then will ring Geoff. Ta everyone , Regards, Craig.
July 18, 201412 yr Sounds like a possible air leak, or that jet or passage plugged. Run a fine wire through it to be sure! Corrosion may be restricting it if it has been stored. Although 35-36 jet may be more common today with the alcohol induced fuels. Edited July 18, 201412 yr by copemech
July 24, 201412 yr Stock jetting for my 04 is 35 pilot, and my mixture screw is out 2 1/2 turns so I'm thinking of going up to a 38 so the mixture screw will be in a more effective range.
July 24, 201412 yr Author Well Thanks people for advice, but took it to Sandifords offroad as I could not solve. Geoff has had a look at it in there workshop and found out the engine builder had left out the crank seal !!!!! Im not happy as there was another problem with the build that I sorted out ! and this Guy said he had 21 years of building trials engines ! Am not happy at all with engine builder, but well done to Sandifords Geoff for solving the problem, just waiting for the crank seal to arrive from the engine builder then hopefully get on the thing and give it a go !
July 24, 201412 yr dont know how someone could miss that , but then again ive heard of lads missing pistons out in tank engines , there were 12 though so maybe they got a bit sick towards the end
July 28, 201412 yr Author Sorted now, thanks to Geoff and Martin at Sandifords off road, Runs like a new one, after all that carb cleaning and taking it off and on the bike looking for the answer ! Just got to get time to get out on it, as its taken sooo long to sort. Cheers everyone for the advice. Craig.
August 4, 201412 yr Author Cheers Bud, Its like a new un and running perfect now. At long last !!!!! Craig.
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