1978 Spitfire restore/restart, problems past idle

[Paintdan85]

Hello Guys,

I got a 1978 Spitfire with a kohler 340 engine, it has been barn kept for 10years then thrown out in the weather for another 21years since its last use. I cleaned it up re-ran some mouse chewed wiring, had to add a new CDI (it was missing) and a few other misc parts. When I took apart the butterfly carb, the high speed needles where corroded away, and I could not get the sled to even fire up, so I bought a new Mikuni vm30 carb with a 270main jet and 35 pilot. Throw it together and it would idle and die, new plugs where heavy soiled, so I cut the pilot back to .25 and I now have the sled idling, when I press on the throttle, you can hear the change of the sound of the engine running at idle, but it never picks up speed after idle (at least not enough to open the clutch)

Any ideas guys? I almost have 1k into this project and so close to making things run, its starting to frustrate me! I haven't removed the motor, just really cleaned things up, do you think its a carb out of adjustment issue, timing or ignition??? Thoughts?

I was looking up online and a lot of people where mentioning the CDI, and there was a way to test it in the service manual, so I looked up the service manual, and It says to check for continuity / ohms and the CDI that I just bought and put in to the sled has no continuity on any of the leads, so I dont know if It could be just a bad cdi?


Dan

[Paintdan85]

here is the carb I bought for it:
https://www.ebay.com/itm/Genuine-Real-M ... 2749.l2649



here is the service manual, page 80 is where I found testing the CDI:
http://www.vintagesnow.com/John_Deere_f ... July79.pdf

[WinnipegStPaul9]

The first three things to do is: change the crank seals, change the crank seals, and change the crank seals. Not doing so will lead to burning the engine down.

DA

[Matt]

Per the service manual, stock main jet should be 210, so you're way too rich. The 30 pilot should have been correct but the 25 may work. Here's a link to the service manual for your use: http://vintagesnow.com/John_Deere_files ... July79.pdf

Also stock slide valve is a 2.5 and you have a 2, but try it first before you buy a new slide valve, they aren't cheap and it may work.

[nick80lf]

I could be wrong but I was thinking that the round slide carbs used on these were an odd "small body VM30" (similar to the Snowfire's). Not trying to say the carb you have will not work, just something to keep in mind.

Sent from my HTC One A9 using Tapatalk

[75522]

Agree with DA. He gave the same advice to me two years ago. I tried all the 'easy' stuff, to no avail. Finally took his advice and changed out the crank seals (cleaning up the stator in the process) and now it flies! The bogging after idle is directly related to oxygen getting into engine through the crank seals.

[Paintdan85]

Hello Guys,

Thanks for the tips, I seen about the seals, but I figured if air was leaking past the seals that it would be running lean, but would still be running with no issues. I bought a gasket kit will all gaskets and seals, I just got finished pulling the whole motor apart and getting ready to bring everything to the sand blaster to clean things up (the sled was sitting outside for over 21years!) so things are kinda rusty / corroded. Once I get everything back together I will update all you guys!

I just got a liqufire 440 up last year, and had a blast on it, no seal changes on that one, so I figured id be safe with the seals on the spitfire too, now on my liquifire (i was thinking that it just needed adjusted) Idle is fine, low is great, mid throttle its good till about half throttle, then it bogs down also, do you guys think its the seals also or just out of adjustment?

Thanks
Dan

[Paintdan85]

Hello Guys,

I got the case all blasted tonight and ready to put back together, the next question I got for all of you, the Stator According to the manual posted by Matt above pg 79, testing the Stator with my Mutli meter on omhs, the L1 charging coil is reading within spec 182ohms, Meanwhile the L2 coil is reading 179 ohms, which according to the manual should be 1.5 to 2.3 ohms which is no where close. Dose this mean the Stator is bad? Could this also be a reason why the motor dosent want to throttle up?

Also my coil pack (page 81 in the manual) it says to put the ohm meter between both spark plug wires and you should have 1100 to 1700ohms, mine is pulling 1930ohms again since it is out of spec, would I have to replace this also?


Any help is appropriated guys! Thanks

Respectfully,
Dnaiel McKay