JLO 295 will not fire

Route 6x6 Discussion Board: Shop Talk: Tech Tips and Q&A section: JLO 295 will not fire
Top of pagePrevious messageNext messageBottom of pageLink to this message   By Fran on Unrecorded Date: Edit

I have and older max with a JLO 295 engine in it. I am getting spark and I have compression, but it does not seem to be getting fuel to the cylinder. I am getting gas into the carb(tillotson HD)but it is not flowing through to the cylinder. Any suggestions?
Fran

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Kevin Percy on Unrecorded Date: Edit

Fran,
Has the engine sat unused for a while ?
If so I would check for a sticking fuel inlet needle in the carb. You have to pull the carb off and remove the plates on the bottom to get at it, it is in the main body of the carb. If you carefully remove the lever (don't lose the wee spring under it) and pull the needle out gently, clean it and put it all back together it should run. If the needle comes out real easy (falls out)check the diaphram (it looks like a gasket with an aluminum disc attached to it)for cracks or holes. If you can see light through it anywhere you need a new one. Make sure you put the plates and fuel lines back in the right order. Ideally you should install all new gaskets when you put it back together.
Kevin

Top of pagePrevious messageNext messageBottom of pageLink to this message   By ISAAC EISENMAN (Tropicjungleboy) on Unrecorded Date: Edit

HEY FRAN:

the situation that you mention looks like the follow causes:
* loose or brocken vacuum-pressure hose (from engine housing to carburator)
* clogged needle-seat
* improper adjusted needle actuator...this actuator should be "flat" at center of carburator
.....this actuator is activaded by vacuum-pressure diafram that contain a metalic point at center..when piston get down inside cylinder liner built up pressure below piston area..this pressure activate (lift) this metallic point and open the needle-seat gap so gasoline can get thru the ventury ( tunnel inside carburator where the gas/air ratio is performed)..when piston get up, a vacuum is formed below piston...this vacuum return the diafram so needle gap get closed and interrupt the flow of gasoline from carburator pump (lower membrane area of carburator)to ventury.....
hope that this explanation will help to resolve your jlo 295 gas starving problem....

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Eugene Kochnieff on Unrecorded Date: Edit

Hi Fran.

If a 2 stroke blows a crankcase seal it wont move
the air fuel mix into the cylinder to be compressed.

Check the seals around the crankshaft and all
gaskets on the crankcase.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By david berger (Davidrrrd) on Unrecorded Date: Edit

hi fran, unless your using it all the time the tilotsen has a reputation for lasting only one season per rebuild, i'd get a kit and rebuild it just to be on the safe side, the kit will have new gaskets and pump valves, diaphram's, and also neadle valves, inlet valve, and lever too!
everything you need and probly in the nayborhood of $20.00,
iff your using it all the time and the gas stays clean it will last years,
it's the wether and condensation(water) that screws with them the most,

Top of pagePrevious messageNext messageBottom of pageLink to this message   By fran on Unrecorded Date: Edit

Thanks for all of the helpful hints on solving my problem! The carb has already been rebuilt this year. I am going to look into the crankcase problems. Any suggestions on what to look for in dammaged seals, or do I just have to tear the whole thing apart?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By roadwolf on Unrecorded Date: Edit

fran, usually the seals go on the pto side 'cause it is exposed to dirt and grime.
block off the carb and exhaust. install a schrader valve and a 0-20 psi gauge to one of the blockoff plates. rotate engine to approximately B.D.C. install 6 to 8 lbs, no more as it could blow out the seals, then spray a little water in suspected areas as seals, base gasket etc.
if it holds for 3 plus minutes go back to your carb.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Daron on Unrecorded Date: Edit

Fran, I had a problem similar to yours.My carb was brand new from Richard Clark.It would not start.Choking did no good.I sprayed some gas (do NOT use starting fluid!)into the intake, and it fired right up-then stalled.I had to spray it while it was running to keep it from stalling.Turns out, there was air trapped in the fuel pump part.Once I got it full of fuel,it run fine.It has been 2 weeks now..a little choke, turn the key.Hope this helps.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jeff Norris on Unrecorded Date: Edit

I have a similar fuel problem. A little gas directly into the carb. on my MAX II 14hp Vanguard and it fires and runs the gas out then dies. I disassembled the diaphram, didn't see anything out of the ordinary, replaced a slightly worn fuel line(just in case), reassembled and it started and ran fine. After it sat for a month or so I'm back to the same problem. Is this common ?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By ISAAC EISENMAN (Tropicjungleboy) on Unrecorded Date: Edit

HEY FRAN:

check for your gas-vacuum proper line conections....they should go as follow:

one line is vacuum/pressure from engine block...this line activate the gasoline integrated pump

one line is the input gasoline from tank
one line is the overflow or return line to tank

how to identify each one??

easy

the vacuum port will only allow you to blow (pressure) or suck (vacuum) a little... on any of above actions you should get resistant (end of diaphram gap) and should retain the vacuum or the pressure...otherwise the diaphram has leak (brocken diaphram or not enough torque on support bolts)

on the remain two lines, they has a couple of internal flapper valves that, if they are ok, only permit flow on one direction...

some carbs have and integrated screen filter device that have sense to check

the "float" device is a needle and seat design that must have to be flat level between bellcrank end (where upper part of center of diaphram touch it) and the carb body

check for leaks on the line that came from engine block.....if you don't have enough vacuum-pressure source (due to low compression on engine or brocken engine's cranckshaft seals or leak between the two halves that makes the engine crankcase)your fuel pump or the "float" device won't work at all............ if you can replace fuel hoses with transparent ones you can check "dinamic gasoline flow action".........

hope that this explanation will resolve your jlo 295 situation........

Top of pagePrevious messageNext messageBottom of pageLink to this message   By zerbo on Unrecorded Date: Edit

I also have a jlo 295 im rebuilding, the crank shaft bearings seem to look fine. can anybody tell me if i should replase them, or would they be okay. I have a older max 11 can sombody also tell me what size drive belt i need.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By mark harding (Promoza) on Unrecorded Date: Edit

hello what year is your MaxIV I also have an older one a 1975 with a 484cc motor glad to see I'm not the only one with an old one wish i could help with your ???s but i cant good luck finding help
mark

Top of pagePrevious messageNext messageBottom of pageLink to this message   By ISAAC EISENMAN (Tropicjungleboy) on Unrecorded Date: Edit

HEY ZERBO:

about the variable speed belt on your max ll with jlo 295 (my actual configuration)..i found good result on 28mm x 1180mm

asuming that an inch is equal to 25.4mm

that's equal to 46.45 inches long and 1.1 inches wide

now..on sae values a variable speed belt come on 1/16 of an inch wides.....each 1/16 of and inch equal to 1.5875mm.......so 28mm equal to 17.63/16...but variable speed belt on sae measures comes on 17/16 * 19/16* 22/16

numbers on sae belt (good year-dayco) goes like

1722-460....means 17/16 of an inch wide, 22 degree cut, 46.0 long

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Kevin Percy on Unrecorded Date: Edit

Zerbo,
If you are not sure about the bearings put new ones in while you have it all apart. They are relatively cheap and then you know they are O.K. You'll need a press to take the old ones off the crank. To put the new ones on wrap them in tin foil and put them on a 100w light bulb (turned on)for about 20 minutes to heat them. They should slide onto the crank, work fast so they can't cool down before they are in place. If they don't go all the way on you will have to press them on the rest of the way. Do not use a hammer , and only put pressure on the inner part of the bearing !

Top of pagePrevious messageNext messageBottom of pageLink to this message   By zerbo on Unrecorded Date: Edit

I think when i painted the frame it had a plate that read 1977 i cant remember. i got this max for 100.50 dollors what a steal.it was pretty clean, has a red top only had one small hole where front tire rubbed fender. painted frame, replased axel bushings,new chains,new seats lights.was pretty excited to join the 6x6 ranks.just nead to learn more about these motors so i can get more riding time.its been siting alot.thanks for the other info guys.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By zerbo on Unrecorded Date: Edit

isaac, your saying i can get a belt this size, 1722-460 from good year, or dayco. I checked RI Industries but was hoping to get one a little cheaper.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By ISAAC EISENMAN (Tropicjungleboy) on Unrecorded Date: Edit

HEY ZERBO:

about variable speed belt selection:

be aware to avoid purchasing a low price NON variable speed belt......they look the same external size but diferent construction design and diferent raw material...normal pulley belt will worn out very easy...and a worn out belt will drive your max NOWHERE!!!!......down here such belt (1722-460) hit the $ 38.00 figure..but if you want the best you should ask for snowmobile aplication kevlar variable spped belt...(at least gates rubber co made it)


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