Starter options with new style heat muff

[engineerorange]

I have an RV7 with a circa 2016/2017 vans exhaust/heat muff. The muff is the type that clamps over both crossover pipes in front of the sump. I have the garbage Skytec lightweight starter that will only start the engine if it/the battery is warm and the battery is fully charged. Preheat or summer and flew in the last few days? No problem. I understand all the starter circuit testing etc. I want a starter that requires less amperage than a permanent magnet direct drive starter.

Does anyone have any starter besides a Skytec LS mounted on a vertical induction o-360 with the van's heat muff? How/what did you modify to gain clearance for a different starter or is there a starter that fits with the van's heat muff? A B&C definitely will not fit.

 

[blaplante]

I have a hard time believing that you don't have a starter problem with the Skytech, or it's wiring. Never heard of anyone having to go to a bigger starter.

• What gauge wire runs to the starter?
  Check the crimp terminals on it. Pull HARD.
  Check the engine to airframe/battery ground strap. Good contact to bare metal? Heavy enough gauge wire to return the starter current?
  Starter contactor... could have burnt contacts internally
  Battery - maybe try a start with jumper cables from a charged car battery? We once let our PC680 go pretty dead... it was never the same afterwards... always weak cranking
  What's the compression ratio on your engine? With high (10:1) CR pistons the engine will be hard to crank

 

[dmattmul]

I have a hard time believing that you don't have a starter problem with the Skytech, or it's wiring. Never heard of anyone having to go to a bigger starter.

• What gauge wire runs to the starter?
  Check the crimp terminals on it. Pull HARD.
  Check the engine to airframe/battery ground strap. Good contact to bare metal? Heavy enough gauge wire to return the starter current?
  Starter contactor... could have burnt contacts internally
  Battery - maybe try a start with jumper cables from a charged car battery? We once let our PC680 go pretty dead... it was never the same afterwards... always weak cranking
  What's the compression ratio on your engine? With high (10:1) CR pistons the engine will be hard to crank

The SkyTec lightweight starter is a known amp hog and the fix has been go to a different starter or use a EarthX battery that can supply enough amps to turn it over. Read the specs. Believe it or not, permanent magnet in rush current motor requirements are significantly higher than other starter motors.

 

[rockwoodrv9]

This is what I have. The starter works well. Low heat output from the muff but it all fits. Hope it helps.

 

[engineerorange]

This is what I have. The starter works well. Low heat output from the muff but it all fits. Hope it helps.

That looks like it might work, but over $1500 for that starter may lead me to custom heat muff fabrication so the B&C will fit.

 

[BillL]

The SkyTec lightweight starter is a known amp hog and the fix has been go to a different starter or use a EarthX battery that can supply enough amps to turn it over. Read the specs. Believe it or not, permanent magnet in rush current motor requirements are significantly higher than other starter motors.

The acceleration current is higher because the permanent magnets are the field and not compromised by sharing with the rotor. Once moving and engaged the PM motor/starters have much higher torque/amp than wound fields.

I would go back to basics on the starter + starting system if there is a spinning issue. The second compression stroke requires the highest amps/torque - so the compression ratio comment applies to the first rev.

I have and IO360 James cowl and AWI exhaust, so no help/comment on the heat muff.